text:
Can Feather bring back a spell with Jump-Start?
Jump-Start is a keyword ability that allows a card to be cast from the graveyard, and then exiled afterwards. (For example, Maximize Velocity.) According to the Comprehensive Rules, the exact wording of the cast-then-exile effect is "[i]f this spell was cast using its jump-start ability, exile this card instead of putting it anywhere else any time it would leave the stack."
If I cast a spell using Jump-Start while Feather, the Redeemed is in play, can I use Feather's ability to bring the card back into my hand (at the next end step) after casting it?
On the one hand, both Feather's effect and Jump-Start's effect are replacements that apply when the spell leaves the stack, which makes me think I can choose which applies.
On the other hand, Jump-Start's replacement exiles it instead of putting it anywhere else, not just the graveyard—so could it then replace Feather's replacement, exiling it anyway?

You can choose whether Feather, the Redeemed affects the spell or not.
From Gatherer rulings of Feather, the Redeemed:

If another replacement effect instructs you to exile an instant or sorcery spell, such as that of Dreadhorde Arcanist or the flashback keyword, you may choose to apply Feather’s replacement effect first. If you do, Feather’s delayed triggered ability will return that card to your hand.

Note that the Flashback keyword has almost exactly the same wording as the Jump-start keyword:

If [the relevant ability was used], exile this card instead of putting it anywhere else any time it would leave the stack.

Hence, the ruling above applies to Jump-start in the same way as it applies to Flashback.

Yes, Feather's ability can return jump-started spells to your hand.
Feather's effect is a replacement effect. When an eligible spell would be put into your graveyard as part of its resolution, you may exile it instead and return it to your hand at the end of turn.

614.1a Effects that use the word “instead” are replacement effects. Most replacement effects use the word “instead” to indicate what events will be replaced with other events.

The exile part of jump-start spells is also a replacement effect that affects where the card goes after resolving:

702.132a Jump-start appears on some instants and sorceries. It represents two static abilities: one that functions while the card is in a player’s graveyard and another that functions while the card is on the stack. “Jump-start” means “You may cast this card from your graveyard by discarding a card as an additional cost to cast it” and “If this spell was cast using its jump-start ability, exile this card instead of putting it anywhere else any time it would leave the stack.” Casting a spell using its jump-start ability follows the rules for paying additional costs in rules 601.2b and 601.2f–h.

Your example of Chemister's Insight is a bad one, because it wouldn't be eligible for Feather anyway, since it doesn't target a creature. Maximize Velocity would be an appropriate example.
As you can see from cards with Jump-Start, they fit the definition of replacement effects, and the following rule applies:

616.1. If two or more replacement and/or prevention effects are attempting to modify the way an event affects an object or player, the affected object’s controller (or its owner if it has no controller) or the affected player chooses one to apply, following the steps listed below. If two or more players have to make these choices at the same time, choices are made in APNAP order (see rule 101.4).

Therefore, you can choose to exile a jump-started with Feather so it returns, or exile it through Jump-Start so it won't return.

Good point on Chemister's Insight; replaced that in the question.

Yes you can use Feather's ability on Jump-Start casted cards.
From Feather, the Redeemed's gather page:

If another replacement effect instructs you to exile an instant or sorcery spell, such as that of Dreadhorde Arcanist or the flashback keyword, you may choose to apply Feather’s replacement effect first. If you do, Feather’s delayed triggered ability will return that card to your hand.

So now we need to determine if Jump-Start is a replacement effect. From the comp rules for Jump-Start:

702.132a Jump-start appears on some instants and sorceries. It represents two static abilities: one that functions while the card is in a player’s graveyard and another that functions while the card is on the stack. “Jump-start” means “You may cast this card from your graveyard by discarding a card as an additional cost to cast it” and “If this spell was cast using its jump-start ability, exile this card instead of putting it anywhere else any time it would leave the stack.” Casting a spell using its jump-start ability follows the rules for paying additional costs in rules 601.2b and 601.2f–h.

And from the comp rules of Replacement effects:

614.1a Effects that use the word “instead” are replacement effects. Most replacement effects use the word “instead” to indicate what events will be replaced with other events.

So I would say that Jump-Start is a replacement effect since Jump-Start places the card in exile instead of the graveyard. Since Jump-Start is a replacement effect and Feather's ruling states you can use it on cards that are being exiled due to replacement effects, you can use Feather's ability on the card.
Also, Flashback has near identical wording to Jump-Start and Feather's ruling specifically mentions that it can be used on Flashbacked cards.

702.33a Flashback appears on some instants and sorceries. It represents two static abilities: one that functions while the card is in a player’s graveyard and another that functions while the card is on the stack. “Flashback [cost]” means “You may cast this card from your graveyard by paying [cost] rather than paying its mana cost” and “If the flashback cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack.” Casting a spell using its flashback ability follows the rules for paying alternative costs in rules 601.2b and 601.2f–h.

Jump-start is a self replacement effect. According to 616.1a, if there are multiple replacement effects, as is the case here, the self replacement effect must be chosen.

@Aetherfox How does Jump-Start differ from Flashback in that regard? Feather's Gather page specifically mentions it can grab Flashback cards.

Huh, yeah, I must be wrong then. Clearly I don't understand SRE's as well as I thought. What is a good example of an SRE then?

@Aetherfox SRE replace the base effect of a card with something else. Things like Metalcraft. Look at Galvanic blast. Its effect of deal 2 damage is self replaced with deal 4 damage if you have metalcraft.

"Feather's ruling states you can use it on cards that are being exiled due to replacement effects" More precisely, on cards that would have been exiled.

@Brilliand The present progressive "are being exiled" implies that Feather's replacement takes place at the same time as the other replacement effect. But for Feather to work, it has to be applied before the other effect.

@Acccumulation Yeah, I realized within seconds that I was wrong.  The other replacement effect doesn't even activate, since it says "anywhere else" rather than simply "anywhere".


text:
Can I activate my "once per turn" effect twice if the activation is negated?
Let's assume I have two copies of "Spellbook of Secrets" in my hand. I activate one, and my opponent chains to it with their set copy of "Solemn Judgement". Am I able to activate my second copy? "Spellbook of Secrets"' effect reads:

Add 1 "Spellbook" card from your Deck to your hand, except "Spellbook of Secrets". You can only activate 1 "Spellbook of Secrets" per turn.

Since "Solemn Judgement" negates the activation of cards, would I be able to activate my other copy, or does it not work that way?

I wanted to put "hard once per turn" in the title, but I'm unsure if unofficial terminology is alright for this sort of thing. If someone could also clarify rules for that, I would appreciate it.

Good post, the difference between activation and negation is relevant. Regarding the "hard once per turn" to be honest I have never heard it used.

Hard once per turn, or HOPT, is a pretty common way to label effects like these. It's even used in the page I linked earlier. It's in contrast to soft once per turn effects, which cards like Red Eyes Darkness Metal Dragon have that can be activated multiple times per turn, but only once per turn if the card remains face up on the field.

Not "once per turn if the card remains face up on the field", but once per turn per card is a better way to say it.

Well, I think that once per turn per card reads more explicitly. However, the term hard per turn could be mentioned in the answer as to inform/encourage about its existence.

The answer is yes.
There is a difference between negating the activation and negating the effects of cards. "Only once per turn" effects, like "Spellbook of Secrets", may only be activated once per turn, and if the activation is negated you can use them again. However, if the effect is negated, say, with something like "Ash Blossom & Joyous Spring", you have still activated the card, and you cannot activate another copy.
You can read more about the distinction among these mechanics here.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


text:
May I use "Ash Blossom & Joyous Spring" to negate the effects of cards that send from deck to grave, but not in the specific scenario?
Let us assume that my opponent is playing a Shaddoll deck, and has activated "Shaddoll Fusion" on the first turn of the game. Since I have not taken a turn and have no monsters special summoned from the extra deck on my side of the field, the opponent is unable to send the Fusion materials from deck (part of "Shaddoll Fusion"'s effect), but can still Fusion summon using materials from hand.
Even though they can't use the part of the effect that sends monsters from deck to graveyard, am I still able to chain "Ash Blossom & Joyous Spring" to negate the effect of "Shaddoll Fusion"?

You will be able to chain Ash Blossom to the activation of Shaddoll Fusion.
Ash Blossom reads:

When a card or effect is activated that includes any of these effects (Quick Effect): You can discard this card; negate that effect.

Because Shaddoll Fusion includes the effect to send cards to the graveyard it counts towards being Ash'd. It doesn't matter if you actually have a special summoned monster on your field, simply having that effect in its effect text makes it viable.
Source: https://www.db.yugioh-card.com/yugiohdb/faq_search.action?ope=5&fid=20586&request_locale=ja

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Atemsis, All-Seeing and Mask of Immolation interaction
Does sacrificing Atemsis, All-Seeing equipped with Mask of Immolation trigger Atemsis' second ability, or does it not trigger because Atemsis left the battlefield already?
Atemsis' second ability:

Whenever Atemsis, All-Seeing deals damage to an opponent, you may reveal your hand. If cards with at least six different converted mana costs are revealed this way, that player loses the game.

Mask of Immolation's sacrifice ability:

Equipped creature has “Sacrifice this creature: It deals 1 damage to any target.”

(Emphasis mine)

"Atemsis' second ability:" That's Atemsis' third ability.

No, it doesn't. While it's certainly Atemsis, All-Seeing who does the damage (so a Circle of Protection: Blue would work to prevent it), the damage is done at a moment when Atemsis, All-Seeing is in the graveyard (it has been sacrificed as part of activating the ability). It has the reveal-your-hand ability only when it's on the battlefield, so it won't trigger.

113.6. Abilities of an instant or sorcery spell usually function only while that object is on the stack. Abilities of all other objects usually function only while that object is on the battlefield.

A list of exceptions follows but this ability is not one of them.

No.
What matters is the state of the board at the moment that the damage was dealt:

603.10. Normally, objects that exist immediately after an event are checked to see if the event matched any trigger conditions, and continuous effects that exist at that time are used to determine what the trigger conditions are and what the objects involved in the event look like. However, some triggered abilities are exceptions to this rule; the game “looks back in time” to determine if those abilities trigger, using the existence of those abilities and the appearance of objects immediately prior to the event. The list of exceptions is as follows:

None of the exceptions apply to things that trigger upon damage being dealt.
This means that when damage is dealt, the game looks at the state of the board to see if there are any triggered abilities that trigger. And as per rule 113.6 detailed in Glorfindel's answer, Atemsis is in the graveyard at that time and thus its ability does not function.


text:
Why the insistence on who has the most dice after removals?
In Ninja All-Stars, combat is resolved by each player throwing the amount of dice specified by the combatants' stats and any bonuses coming from the conditions, then matched dice are removed, then the one who has the most dice remaining chooses which of their dice to be the result.
Except... the rulebook is insistent that the decision of who gets to decide is made after the dice pairs are removed, but since those only ever remove one dice from each player, that shouldn't ever change anything - what am I missing?

In your use of words, it looks to me that you think that dice is singular, but it is actually a plural noun, the singular noun would be die. So the answer says that you must remove all the die that eliminate each other. So you remove at least 2 dice not 1 die.

1 die from each player's pool of rolled dice, which means that there an never be any change in whose dice pool is larger.

1 die from each players pool that matches another die in the other players pool which means that multiple dice can be removed.

Because the dice that are eliminated could eliminate possible results of the since every matching pair must be removed not just one dice from every player.
When they say all possible eliminations must be made, they mean that for each attacker/defender die elimination you can make, you must make that elimination. It is not trying to say that an attacker's own dice can eliminate each other, otherwise we wouldn't have this second sentence saying they can't do that
Beta Rules

Fire and Water eliminate each other.
  Earth and Air eliminate each other.
  Spirit and Void eliminate each other.
When two dice eliminate each other, remove them from the pool of rolled dice. Dice that the attacker rolled can only eliminate dice that the defender rolled and vice versa. All possible eliminations must be made.
Spirit: The attacker is Injured.
  Fire:All ninjas in the attacker’s influence zone, including the attacker, are stunned. (See Stun, page !X!)
  Air:The attacker may move the defender up to 3 spaces in any direction.
  Water:The player who picked Water as the result may move the attacker up to 3 spaces in any direction. The defending player then places the defender in the attacker’s front influence zone.
  Earth: The defender is stunned. (See Stun, page !X!)
  Void: The defender is Injured.

Some examples:
Attacker rolls 2 Spirit and Defender rolls 2 Void

Check for matches
Find a match of 1 Spirit and 1 Void and remove
Check for more matches
Find a match of 1 Spirit and 1 Void and remove
No more dice so attack results in nothing happening

Attacker rolls 3 Spirit and Defender rolls 2 Void

Check for matches
Find a match of 1 Spirit and 1 Void and remove
Check for more matches
Find a match of 1 Spirit and 1 Void and remove
Check for matches
Only 1 dice left and is Spirit so attacker is damaged

Attacker rolls 3 spirit, 1 Void and defender rolls 2 void

Check for matches
Find a match of 1 Spirit and 1 Void and remove 1 Spirit from attacker and 1
Void from defender
Check for more matches
Find a match of 1 Spirit and 1 Void and remove remove 1 Spirit from attacker and 1 Void from defender
Check for matches
The 1 Spirit and 1 Void that are left are in the attackers pool so not a match and the attacker can now chose which effect to use

The bolded text is nullified by the sentence exactly before it - you only ever nullify one dice each, so who has more dice never changes.

@vonBoomslang That is not the case as the second sentence just qualifies what a match is and isn't and the third sentence is informing you to remove all possible matches. I have updated my answer with some examples.


text:
Sheriff of Nottingham - Is the sheriff allowed to take your bribe and still search your bag?
I was playing in a game where I had offered a bribe on my merchant bag. The sheriff, in turn, chose to take my bribe and still search my bag anyway.  Is this type of play allowed?

I saw this in Hot Network Questions, thought it was Law Stack Exchange, and was rather puzzled.

No.
The sheriff can either take the bribe or search the bag, not both. From the rules, in Phase 4 (Inspection):

When the Sheriff has made a decision about a Merchant Bag, he has two choices:

Accept whatever final bribe was offered (if any) and hand the bag back to its owner; or

Reject any bribe that may have been offered and unsnap the Merchant Bag, revealing the cards inside.

Thank you! Darn, when I was playing it, I didn't know this. Time to get my money back!

No, once the bribe is taken is it a binding contract.
Rules

Once the Sheriff has made a choice it cannot be changed.
  As soon as you unsnap a Merchant Bag or hand it back,
  it’s too late to change your mind!
After the Sheriff hears your offer (and after any negotiation
  required to settle the issue), the Sheriff must either allow you
  to pass (accepting any bribe that may have been
  offered), and hand you your Merchant Bag,
  or inspect the bag (refusing any bribe that
  may have been offered).
Normally, all deals you make must
  be honored! However, there are a
  couple of exceptions:
  • Promises of future favors, which take place after the current
  inspection phase, are not binding!
  • A merchant might offer the sheriff a bribe, which includes
  Goods in his merchant bag. Of course, he might be lying
  about the contents of his bag. If he is allowed to pass, when
  he reveals the Goods in his bag, he need only pay the sheriff
  the Goods he promised which actually exist! If he promised
  Goods to the sheriff, which are not in his bag, he does not
  have to pay those.

As a side note in the group I played with bribes where frequently offered to open bags as well.

No, it is not allowed. Only promises of future action are non-binding. See the same question on Boardgamegeek.


text:
Eye of the Storm—Simultaneous or Sequential?
With Eye of the Storm and Thousand-Year Storm on the battlefield, I cast Lightning Bolt. Storm count goes to one, and Eye exiles the Bolt. Through Eye, I copy and recast it, and Thousand-Year Storm copies it once. Storm count to two. This much makes sense.
Now I cast Shock. Copied twice, the original is exiled, and my storm count goes to three. Now Eye copies both Shock and Bolt. Are these two cast in order (so one is copied three times and the other four), or do I cast them simultaneously, only choosing their order on the stack (and copying each only three times)?

There is nothing in MtG that casts multiple different spells simultaneously.

Sequential.
"The player may cast the copies" would simultaneously cast the copies. This is practically impossible to do (since casting is a long and complex procedure), so the card uses the wording "For each copy, the player may cast the copy" instead. The instruction only has you cast a single object, so there's nothing for it to be simultaneous with.

That said, I think that you can stack the Thousand Year Storm triggers in any order. Is that right?

@Arcanist Lupus, Yes. The abilities are only added to the stack the next time a player would get priority. At that point, multiple instances of TYS's triggered ability will need to be added to the stack. Each player in APNAP order adds their triggered abilities to the stack in the order they choose.

Not that APNAP order matters when one player controls all the triggers.  (I mean, it could matter if there are other triggers in play.  But just the scenario as described only features triggers from a single player at a time.)

Right. I was just being complete.

"since casting is a long and complex procedure" -- what does that refer to? Surely you can cast an Instant or a Sorcery by just tapping some mana, showing the card and declaring targets? (plus whatever other choices there are) Doesn't seem too complex.

Rule 601.2 describes the 9 step process to cast a spell. And a couple of those steps are whole paragraphs. In normal gameplay, that is usually equivalent to what you describe, but it can get more complicated.

Not to mention that one can activate other abilities add part of casting spells. How can that all be done simultaneously? Do you do each step simultaneously? What happens if there's a conflict? How do you handle both castings trying to tap the same land? How do you handle reversions? Etc etc etc.


text:
How to find online players for San Juan?
Where is a good place to ask for?
I googled a lot, also googled nicknames I see in San Juan leader board, but no success.
San Juan uses GameCenter in the iOS version, but Apple reduced a lot of functionality from GameCenter and Ravensburger didn‘t implement its own social game network, and it seems they dont do it in the future.
So it is almost impossible to find new player friends because friend requests are not working anymore, even you can send some.

This sounds like an issue with the app you are using and you need to contact the developer to get help.

Yes, the game manufactor could change it maybe, but they dont do updates anymore. But still a lot of people play this game, I can see them in the leaderboard but I‘m unable to contact them. This people got there friend connections before Apple changed/reduced the GameCenter functionality. So it seems I have to find other players without GameCenter, like the answer on brettspielwelt says. I‘m already searching there ...

I am not sure what you expect anyone but the developer to do to help you fix the issue of being unable to contact or make connections with people on the leader board.

Maybe there are ways to contact Game Center members outside the game (it uses a REST web service). And the tip about other communities was great. The question is ‚How to find online players?‘, not contact them only in the app over Game Center. Is it clearer now?

Asking about contacting game center members outside of the game is not in the scope of this site and you might be able to get an answer on the apple stack exchange site.

Then delete the question

You could consider joining BrettSpielWelt.
http://brettspielwelt.de
You may still play on your iDevice, even though it will be through the browser and not the San Juan app.
The user interface takes some getting used to, but once you get through that, it's a good way to find opponents for quite a few boardgames.
As a distant plan B, you may download JSanJuan, and play against the computer.
http://www.compoundeye.net/jsanjuan/

While this does give options to play online I don't think it addresses the question which is related to playing on iOS and not a computer.


text:
Can I cast a spell in combat check after having rolled?
In the Arkham Horror board game, consider the following:
I am about to do a combat check fighting a monster. I already decided I want to use a spell in combat (e.g. "Wither"; it is untapped, I have enough hands). Can I roll the dice without casting the spell at first and if it is not enough, try casting the spell and (if successfull) roll additional dice?
I could not find a convincing answer in the rules and FAQs. It definitely states two different things:

In order to use spells, you have to have enough hands
In order to gain their bonuses, you have to successfully cast them

So while you have to decide on the choice of your weapons / spells / hands before a combat check, just carrying a spell (or, more accurately, "spellbook") into combat does not seem to force you to cast it. Moreover, using hints works exactly this way (you can choose to use them to roll additional dice).
Is there any information on this that I have missed? I know the question might seem odd at first, but the longer I think about it, the less sure I am about the answer.

From the Rules (Page 13)

Skill Checks / Modifiers
  This number is added to or subtracted from the investigator’s skill value before the player makes the check. The result is the number of dice the player rolls to make the check. Note that modifiers always apply to the number of dice a player rolls for a check, not to the results of the individual dice.

A combat check is a skill check, and a spell is a modifier (with additional rules) to that check, therefore you must decide to use the spell before rolling the combat check, and you can not change your mind after the check to roll additional dice if you failed.
Thematically it makes sense as well, spells are hard to cast, require preparation and mental strengthening, so it's best to have them at the ready and in hand.


text:
Is Heritage Druid's ability limited by summoning sickness?
Heritage Druid's ability is:

Tap three untapped elves, add {G}{G}{G} to your mana pool

Once I play Heritage Druid, can I tap three elves (Heritage Druid being one of them) and get {G}{G}{G} to my mana pool?
Just trying to be specific here, thought that several players might have the same problems and could solve it with this thread. But still, thank you all for reading and trying to answer this problem for me.

I don't see how it's relevant to the question, but no, you can't Stifle that ability. It's a mana ability.

I looked at that question and I don't see where in the answer it talks about using abilities that do not have a tap symbol as part of the cost even though it was mentioned in the question.

I disagree with the duplicate, while the question is about summoning sickness certainly, the specifics of an ability that involve tapping creatures (potentially even this creature) but don't use the tap symbol as part of a cost are not covered in the duplicate question. We should never use the assumption that an answer is comprehensive and covers all cases, so the fact it doesn't say you can't do this means you can. Particularly with how much magic's rules have changed.

@Andrew From the duplicate's answer, under "How are the creatures affected?": Summoning sickness does not prevent you from paying other costs, even if they involve tapping the creature.

I added some examples to my answer in the linked question, including one that specifically addresses Heritage Druid.

According to gatherer it is not impacted by summoning sickness since it doesn't have the tap symbol.

Since Heritage Druid’s activated ability doesn’t have a tap symbol in its cost, you can tap creatures that haven’t been under your control since your most recent turn began (including Heritage Druid itself) to pay the cost.


text:
Can I use the Caestus with a shield on?
So, the Cestus has a special ability that, if you consume 3 Stamina, you can use it to attack, even when it is a "backup slot" of your weaponry.
Additionally, there is a rule saying that a player may make as many attacks as they have weapons in their hands.
So, if I have a primary weapon (the Longsword, for example), and a shield, and then place the Cestus in a backup slot (on the shield hand, for example) can I attack with the Cestus as well as the sword each turn, or does this just allow me to attack with the Cestus instead of the sword?

Yes, you can attack with both your sword and cestus.
The wording in the rule book (pg. 22) is as follows:

During an activation, a character can make up to one attack
  with each weapon they are holding in their hand slots.

The special ability of the cestus explicitly states you can use it to attack even when it is in your 'backup slot'. There is no qualifier regarding how many weapons are equipped in your hands. This special ability on the card overrides the general rule on attacks (hence the reason it's a special ability)
This means you could have a 'two-handed' weapon equipped and your cestus in your backup slot, or two single handed items and your cestus in your backup slot.


text:
Group of three tiles containing 2 Jokers
Assume, that there is such situation:
Player A creates a group:

[blue 8] [Joker] [Joker]

and declares, that it is a set of eights.
From this moment these Jokers should be treated as two eights, or is it possible to threat them as blue 9,10 or blue 6,7?
Also, if the declaration of eights is not valid, could these jokers be treated as blue 7,9, despite 8 is not in the middle position?

I'd have to look up the official rulebook, but if I'm not mistaken, Player A should not only declare it's a group of eights, but also specify the exact colors (e.g. 'red 8' and 'green 8').
This is further supported by e.g. this page:

However, a player who has in hand the tile which is represented by a joker on the table, the player can substitute the real tile for the joker and then re-use the joker in some combination on the table.

(emphasis mine); there's only one tile it represents.
Since you've tagged it house-rules, there is room for some variation on the rules. Some of them are discussed in the linked page; when I was a kid, we played it in a more liberal way than you describe; during your turn, you could use the joker for whatever tile you want (i.e. you don't need to substitute it), as long as the final configuration consisted of valid sets only. That meant e.g. that if you had a blue run of 1, 2, 3, joker, 5, 6, 7, you could basically take out the joker and do whatever you want with it.

I was about to tag it with [rules], but it seems that there is no such tag and I didn't noticed that [house-rules] tag was used. Anyway, declaring even colors seems to be against rules: "In the case of a group of 3, the joker can be replaced by the tile of either of the missing colours."


text:
Alternative costs stacking (flashback+spectacle)
I cast Slickshot Lockpicker, which says:

When Slickshot Lockpicker enters the battlefield, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

In my graveyard I have Skewer the Critics which has:

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)

I have thus 2 alternative cost at the moment. One is the mana cost (from flashback), one is the spectacle cost (assuming an opponent did lose life this turn).
How do I choose which cost apply? Can I replace the mana cost with the spectacle cost, and end up flashbacking for {R}?

No, you can't combine alternative costs. You have to choose between the original cost of 2R, Spectacle R, and Flashback 2R. Since the card is in your graveyard and only Flashback lets you cast it from there, you can only choose Flashback 2R.
Alternative costs are only an alternative to a spell's mana cost, not to other alternative costs:

118.9. Some spells have alternative costs. An alternative cost is a cost listed in a spell’s text, or applied to it from another effect, that its controller may pay rather than paying the spell’s mana cost. [..]

601.2b If the spell is modal, the player announces the mode choice (see rule 700.2). If the player wishes to splice any cards onto the spell (see rule 702.47), they reveal those cards in their hand. If the spell has alternative or additional costs that will be paid as it’s being cast such as buyback or kicker costs (see rules 118.8 and 118.9), the player announces their intentions to pay any or all of those costs (see rule 601.2f). A player can’t apply two alternative methods of casting or two alternative costs to a single spell. [..]

Hypothetically, if Slickshot Lockpicker granted you the ability to generically cast Skewer the Critics from your graveyard, rather than just granting it Flashback, you could cast it for its spectacle cost.

I take it if Ancient Grudge is targeted, it can be cast for 1R or G? The sentence "The flashback cost is equal to its mana cost." doesn't overwrite the previous flashback cost?

@Acccumulation The Flashback rules don't say it explicitely, but if a card has multiple instances of Flashback, you choose the one you want to use. Flashback is simply an ability added to the object and does not overwrite other abilities. So yes, you could pay either 1R or G.


text:
Mysterious move
I'm watching a NHK cup match between Hane Naoki and Chang Hsu with japanese commenters so unfortunately I can't understand the explanations, and there is a move from black I can't understand (move 3 in the diagram). The letters are other potential moves I would find more natural.
$$c
$$ --------------------
$$ -. . . . . . . . . . . . . . . . . . .-
$$ -. . 3 X . . . . a . . . . . . . . . .-
$$ -. . O . . . X . . O . . O . . X . . .-
$$ -. . . O . . . . . . . . . . . . . . .-
$$ -. . . . . . X . . . . . . . . . X . .-
$$ -. . O . . . . . . . . . . . . b . . .-
$$ -. . . . . . . . . . . . . . X . O . .-
$$ -. . . . . . . . . . . . . . . . . . .-
$$ -. . O O . O . . . . . . . . . . . . .-
$$ -. . O X . . . . . . . . . . . . . . .-
$$ -. . X . X . . . . . . . . . O O O . .-
$$ -. . X O X . . X . . . . . . O X X . .-
$$ -. X O 1 X . . . . . . c . . O O X . .-
$$ -. O 2 . . . . O . O . . . . . X X . .-
$$ -. . O . X . . . . . . . X . . . O . .-
$$ -. . . . . X . O . X . . . . . O . . .-
$$ -. . . O . . . . . . . . . . X X X . .-
$$ -. . . . . d . . . . . . . . . . . . .-
$$ -. . . . . . . . . . . . . . . . . . .-
$$ ---------------------

So I have two questions :
1) How many points is worth black move ? (Maybe that's too early to decide). A player stronger than me (~3kyu, I'm ~13kyu) told me these kind of moves were worth ~15 points  but I was not convinced.
2) What is the exact meaning of this move, and why play it instead of e.g the other moves indicated ? I feel the purpose is stabilize the black group and making points, but playing on the other side seems more interesting to me as it's also potentially taking away white basis.

It would be great if you could make your question self-contained. The markdown allows us to insert board positions. You can look at some other Go questions to see how it's done, it's unfortunately not documented in the markdown help. This will greatly help us understand, what kind of move you are actually asking about.

Here is a post that uses this markdown syntax: https://boardgames.stackexchange.com/revisions/42049/4 The raw markdown of this post is available here: https://boardgames.stackexchange.com/revisions/8631aa22-3d00-4833-b523-a3de5cf40756/view-source

There's an instruction on how to use the markdown in the tag wiki.

@Glorfindel ... which also just links to another site for the actual documentation. The place where this should be documented, is the help that's shown when you click on the question mark symbol in the markdown editor of this site. Obviously, that's nothing you or I can fix, that's up to the people running Stackoverflow.

@Forget I was ever here : thanks for your edit ! I didn't see it as I was copying the game. Maybe my edit is better since people can modify the codes, and moreover I could add several alternative moves that seem more natural to me. But your edit is really appreciated thanks a lot !

No apology necessary - my edit was only meant to be temporary.

I will concentrate on the question 3 vs. a. While a move at a will also settle black's top left group, it helps the two white stones to make shape and build up pressure towards blacks top right corner. It also takes out other possibilities of attacking the two white stones like building a black wall towards the centre. On the other hand, 3 is a perfect move, it has a large continuation move at b17 when white does not answer (not necessarily played out immediately, but it is there).
And I think that fixing the weak black groups has priority over going for pure profit on the board, given the whole-board situation.

Many thanks for the answer. I'm not sure I perfectly understand but I'm only 12 kyu so it will surely become clear later.


text:
What are the rules regarding mutual support?
What are the rules for when you are allowed to support a supporting unit?
For example, if France has units in Belgium and Holland, are they both allowed to mutually support each other, increasing their defensive strength to 2 each?
Let's say Germany has an Army in Ruhr and a Fleet in the North Sea. If the fleet attacks either Belgium or Holland with support from Ruhr, does this fail?
Or is France not allowed to have two units mutually support each other. Does one have to hold and the other can support the hold, thereby making France guess where Germany will attack?
The rulebook states:

Support can be offensive ... or defensive (supporting a hold, support or convoy order)

What are the circumstances where supporting a support is a valid rule? When is it invalid? I don't see any examples of this in the rulebook.

A unit that is supporting is also holding and is always eligible to receive support in its hold.
The relevant quote from the rulebook is:

A unit not ordered to move can be supported by a support order that mentions only its province.  A unit that is ordered to hold, convoy, support, or not ordered at all can receive support in holding its position.

The most relevant thing to notice here is that a unit that is not moving is holding.  A support or a convoy is also a hold.  If a supporting unit is attacked, the unit does not revert to holding (this is a useful flavor justification but is not technically accurate), but rather the unit was holding the whole time.  All that happens is that it is no longer able to support in addition to holding as it is under attack (the support is cut).
As a result of this, two units can support each other, assuming they can each legally support the other (based on adjacency and unit type).  Since each unit is supporting, they are each also holding, and thus each is eligible for support in holding its position.  If one unit is attacked, it's support for the other unit will be cut, but it will still hold and the other unit will support it's hold.
An opponent needs a minimum of three units to dislodge one of your units and thus disrupt your position.  They can do this by either doing a doubly supported attack on a single unit, or by doing a singly supported attack on one unit and an unsupported attack on the other unit to cut it's support.
This is consistent with the basic principle of diplomacy: equal numbers create a standoff, whereas superior numbers (eventually) win.  Your two units can defend against an attack of two units but not against an attack of three units.
Note that you can also support the hold of a fleet that is convoying an army.  This will help prevent the fleet from being dislodged if it is attacked while convoying.

If support and convoy are also holds, then why does the rulebook explicitly list them separately? (as in your quote: "ordered to hold, convoy, support, or ...") You also claim that Toon's answer is incorrect "in many ways", but you specify none, and have no support for that claim. An attacked unit cannot support another, so regardless of what you think about the "attacked supporting unit reverts to hold" phrasing, the result is the same. You need three units to dislodge one of the defending units, or four to dislodge both.

@ikkachu Toon claims that two units in mutual support need 4 units to dislodge them when the answer is three.  He claims that you cannot support a convoying unit when this is patently false.  Even if you want to quibble on whether a supporting unit is holding or reverts to holding, these are both material errors in Toon's answer

@ilkkachu I have removed the note in case that is what was objectionable

You need two units to dislodge a single unsupported unit, right? How do you use three to dislodge both of two units?

@ilkkachu You dislodge one unit on the first turn and the second unit on the next turn

@ilkkachu What's relevant is disrupting the defensive position.  It takes 4 units to dislodge two units simultaneously whether or not mutual support is legal.  Mutual support is important in that it increases the number of attacking units needed to disrupt any defensive units from two to three.

Units can support eachother. But you are not supporting the support. You are supporting a hold.

If a supporting unit is attacked, it needs to defend (hold) so the order defaults to hold. And now because of the mutual support, the held unit receives support from the other unit. You can try this using a decent diplomacy tool (for example jDip).
If both units are attacked, they both hold without support. So "the enemy" needs at least 4 units to dislodge both.

You seem to be saying that if the Belgium and Holland units are supporting each other, and the Holland unit is attacked, then the Holland unit switches to Hold, and the Belgium unit supports it. But that doesn't answer the question of what happens if both are attacked. Presumably, both switch to Hold, and neither are supported, but your answer doesn't directly say so.

The key insight from your answer is great: "A supporting unit that is attacked reverts to a hold order." Thank you for recommending jDip. That tool really helped me play out a few scenarios to see how the rules work. jDip resolves this scenario exactly as you described. For me, it just feels weird that you are able to double the strength of two units with mutual support. My guts tells me that support of support should not be allowed at all, and that you should only be able to support holds, moves, and convoys. I guess I am wrong.

Basically you either support a unit that is not moving (which includes units that are providing support and fleets that are part of a convoy), or you support a unit in a particular move.

It seems like when two units mutual support each other, then both armies are doubling the strength in both territories (total strength of 4 from 2 units across 2 territories). I feel like the player should be forced to choose one territory to get the extra defensive strength.

@aherriot you can dislodge one of the mutually supporting units with an attack from 3 units, which is the minimum "outnumbering force". You don't strictly "double the strength" with mutual support

Thank you everyone for all the feedback. It has really help clarify why the rules are this way. I have switched the accepted answer to Zags answer, because it goes into more depth and is more clear.


text:
How can I make realistic looking homebrew cards?
I am making a homebrew expansion for Dominion and I have been using the GoodNotes app for the card layouts. I thought they looked pretty good until I saw Asper’s Cards and was blown away by how good they looked. Is there any program usable on an ipad browser that can make cards that look like those?

Most fan cards on that site, including Asper's, use an image generator. But I don't know if works on the iPad (which is why I'm not posting this as an answer).

I’m voting to close this because recommendation questions are off-topic for this site. However, I think it could be modified to be on-topic if it were looking for general advice on how to make realistic cards, rather than specific apps for Dominion.

Or one could go the other way and ask what was used to create those specific cards.

As this question stands it is asking for software recommendations which isn't on topic for this site.

I’d like to apologize if I offended anyone else who made homebrew cards. I didn’t realize that there were more than just Asper’s.

@GendoIkari It does work thank you but I don’t think we’re sopposed to answer in the comments.


text:
What defines the curse type?
I am making a homebrew expansion to Dominion and I want to include some more curse-type cards. However, what does the curse type mean for a card? Does it mean - VP, or just something undesirable to have in your deck?

Dark Ages has two other types of cards which are also undesirable: Ruins and shelters.

Curse type is defined by nothing more and nothing less than having the word “Curse” on the card in the type line.
This is true of other types as well, such as “Attack”. Attack does not mean that the card hurts your opponent, it only means that it has the word “Attack” on the bottom. Mechanically and thematically though, it is better to only have Attack type on cards that hurt your opponent.
Certain types in Dominion, such as “Action”, do have special rules that come with them. But many other types have no rules. Curse has no special rules, the type doesn’t mean anything at all.
That being said, making another card with the type “Curse” is not good for a fan expansion. This is because “Curse” is both the name of a card and a type of card, and the only card with that type is the card named “Curse”. If another card with that type existed, then cards that said “gain a Curse” would be confusing and ambiguous... does “Gain a Curse” mean gain a card named Curse, or does it mean gain a card with the type Curse? There is no correct answer. That ambiguity is only ok because there is no other card with that type.
So, if you want a different card that will hurt players, whether by having negative VP or by clogging their deck, just leave off that type. You can see how Dark Ages did that thing by introducing Ruins.

It might be noted that the first edition witch says “each other player gains a curse card”.

Curses are dead cards that do nothing but take up space in your deck and provide negative victory points.
If you look on the wiki at card types you will see that curse type cards are a special card type with only one card name for them.
Wiki-Curse
Wiki-Card Types

Curses are worth –1 VP at the end of the game, and are the only card type to consist of only one card name. All games of Dominion include Curses in the supply, though in many games Curses will never be gained or otherwise interacted with. They have purple frames. The number of Curses in a game is equal to ten times the number of players after the first - 10 Curses for a 2-player game, 20 for a 3-player game, and so forth.

I belive (though I could be wrong), that the wiki was referring to the curse card, as opposed to the curse type.

@MrHiTech Can you give an example of a curse type that is different?

There isn’t anything in official dominion but maybe something like “cursed village” (I know that name is for a different card, it’s just an example) that is + 1 card, + 2 actions, and worth - 1 VP at the end of the game, cost $2. That would be an action-curse, and definitely be of the curse type, but it would certainly not be a “dead card”.

Of course that would only be if the definition of curse is “anything that gives - VP”, which is exactly my question.

Cursed Village is an Action-Doom card types

@MrHiTech I have updated my answer

I was talking about mine (we can call it hexed village) which is + 1 card, + 2 actions, and - 1 VP at the end of the game

And doom means it uses hexes

@MrHiTech No one will be able to answer any questions about your own cards. This answer is designed to answer what a curse card means in the current game of dominion and can't include any of the hundreds of homebrew expansions for the game. I would also say that just because a card gives negative victory points doesn't mean that it is a curse card as in the official game curse cards are something that provide the player no benefit at all.

But be prepared to argue some more if an expansion comes out with another card with the curse type

Also you said “any questions”, but can I still ask game balance questions about my cards?

@MrHiTech Yes you can ask those types of questions but make sure you provide enough detail so people fully understand what you are doing with those cards and be careful about wording so it isn't an opinion or very broad answer wise.


text:
Where do trashed Travellers go?
In Dominion Adventures, when you trash one of the Traveller cards, where does that Traveller go?
The rules seems to imply the Trash pile.
However, since there are only 5 of each pile, I was wondering if there was some specific rules for cards that weren't in Supply like Travellers and Spoils.

If you trash it, then it goes to the trash pile like a normal card.
Same for Spoils and Ruins.
If you exchange a traveler, then it goes back to the original pile.

As a side note, this means that you can gain upgraded cards with Rogue or Graverobber, from Dark Ages.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
What specific strategies have the highest win:loss ratio in Uno?
I decided to delve deeper into this question to discover exactly how effective certain strategies would have on your win percentage. This led me to this Stanford Computer Science project that pits students' individual UNO strategies against each other.
This particular UNO simulator has some issues that I have corrected:

A proper pseudo-random number generator (PRNG-Mersenne Twister)
Support for 2-15 players
Scoring for wins instead of points
Proper rules implementation of initial special cards
Hhandling of draw cards when going out.

I opted not to add a "catch"/bluff mechanic when playing Wild-Draw4, so those can only be played when you don't have a matching color.
I have implemented some basic strategies that you will be playing against:

Play random legal
Play most color
Play most point
Play highest rank in most color
Call random
Call color I have
Call color most
Call points most

These strategies will face off in 100,000+ games multiple times to get a Confidence Interval (CI) for how effective the strategy is. (I am open on direction of how to accomplish this best. Should it be a 4-player game, with 2 copies of the strategy seated non-adjacent to each other (ABAB)?)
So: what is your Uno strategy? Be specific: I'm going to write a program to execute your strategy, and since computers are dumb like me, instructions need to be specific. (If they are not, I will post comments for you to clarify)
Things to think about in your answer:

What card do you play next? Do you try to get down to one color or number, or always keep as much variety as possible in your hand? If you have a pair of 0's and a 9, do you play the 9 to reduce your point count, or play a 0 to keep up some variety in your hand? Do you play Skip, Reverse, Draw Two, Wild, and Wild Draw Four early or late, or does it depend on how many cards other people have?
What do you do if you must change color? Do you call a color with the most cards, most points, least variety in ranks? Do you think about what opponents might have, or only consider your own hand?
Does your strategy change if someone is very close to winning the entire match, i.e. somebody's close to 500 points? How close to 500 do they have to be for you to change how you play?
Does your strategy change if you're losing the hand? How do you decide if you're losing? (Do you start ditching the high-point cards like Wild and Draw Two?)

Don't worry about answering all of those questions, but if you change your play depending on circumstances around the table, please mention it in your answer. Being precise helps me program a strategy that matches what you do, but if you cannot, just give me a general idea and I will post pseudo code of what the computer will do.
Don't worry about having the absolute best answer. I will program your strategy, and edit your answer to show its actual win-rate against other strategies.

Special thanks to @PaulMarshall who gave me a nice wording of the question.

One thing I do is try to peg back the leader, which can involve being nice to my immediate neighbours. in the ABAB seating arrangement this means I'd be helping to attack myself! I suggest playing three or four strategies against each other and varying the seating order and start player. I'll have a go at putting together an answer later - I'm interested to see whether it actually gives much of an advantage over play random!

@tttppp, I am not sure what you mean by "helping to attack myself." I chose 4-player ABAB seating for a reason. I suspect that 4-player is the most common number of players. 2-player suffers from special card Reverse having no meaning. 3-player ABB suffers from always being adjacent to an opponent (since I suspect 4+ players is more common) which might make certain strategies more powerful than they would be IRL. As for not using ABCD seating order, but instead using 2 copies of each strategy, that was becuase seating order does have an effect on win percentages. [...]

If I chose to pit 4 strategies against the others, it would require 6 times as long to test. I would need to test each seating order (ABCD, ABDC, ACBD, ACDB, ADBC, ADCB), and then average the win percentages across all 6. With 2 copies of each strategy, yes you are fighting against yourself, but I intend to sum both win percentages together versus the other two identical strategies. I don't think this simplification should have an adverse effect on the results. BTW, 100k hands takes about 2 mins, and 200 iterations takes 6.5 hours to get an accurate estimate

@tttppp, I am interested if you have a suggestion for how to run the simulator that replicates real life games more accurately though. For one, I would prefer not having to simulate all the basic strategies against answer strategies. Random call, random play is a very bad strategy (initial testing puts it at 40%:60% versus the least capable strategy and it loses twice as often against the best.

"Helping to attack myself": For example, if in a four player game the person across the table from me is doing well, then I might avoid playing a skip-a-turn card, in the hope that the next player can play an attack card of some sort. In an ABAB situation then playing a skip-a-turn card is good because my 'partner' can hopefully win.

Good to hear that random call/play is terrible though. I didn't think there was much skill in Uno!

@tttppp, there isn't a whole lot (simple strategies perform pretty well). When I say rand call, I mean that the strategy calls colors it doesn't even have (which makes wilds usage very poor). If you call only colors you have (I.e play random, call color have (pRccH), the difference between the best and that strategy is considerably less (but not unmeasurable). pRccH is the next worst strategy (the one that beats random by 10%-15%), and strategies versus pRccH win by substantially smaller margins. Simple strats like call colors you have, don't play wilds unless you need to, make big dif

Did you ever make any progress on this?  I don't see any updates on how any of the strategies did...

Getting the excuses out of the way early: I don't play much Uno at all, and when we do play we typically aim to win a hand, rather than keeping score over several hands.  My strategy doesn't take any account of how near to 500 a player is, but presumably you should, as in the optimal Pig strategy.
I aim to get rid of high value cards, but keep a wild card for the end. I also included a 'panic' strategy for when I've been hit with a Wild Draw-4.
One interesting feature is that I occasionally choose to draw a card rather than play a wild card.  I'm not sure whether you're allowed to do this according to the official rules, but we allow it.
Notation:
P - Previous opponent
N - Next opponent
O - Opposite opponent
M - Me
C(X) - The number of cards in player X's hand
min(C) - The number of cards in the leading player's hand

Call:
If I don't only have black cards left:
    Filter out colours I don't have
# Vaguely try to annoy other people
Name the one I have seen the most of so far (including my current hand)
Tie break by colour I have most of, then most recently played
If this is the first turn and I've only been dealt black cards, then pick red because it's my favourite.

Play:
If min(C) <= C(M) / 2 and min(C) < C(M) - 3:
    # I'm about to be trounced - throw away high points
    Play +4, change colour, +2
    If C(P) > C(O):
        Play change direction, skip a turn, 9-0
    Else:
        Play skip a turn, change direction, 9-0
Else if I have more than one black card left:
    # Try to save a black card for the end
    Play +4, change colour
Else if I have more than one +2 or C(N) < 3:
    # Very occasionally try to save a +2 in case there's one left over on top of the deck
    Play +2
Play skip turn, +2, change direction, 9-0, +4
If min(C) > 2 and min(C) > C(M) - 1:
    # I've got a wild card, and there's not much chance I won't get to play it
    Choose to draw a card
Play change colour

Additional 'strategies' that presumably aren't relevant in the AI tester:
If I play my second to last card call "Uno".
If an opponent fails to do this then point it out at the appropriate moment.

The official rules allow drawing when you have a legal play (Renegging). The initial UNO simulator doesn't actually even check of you make legal plays, but it comes with a tester app that considers not making a legal play an error. I have corrected this so the simulator plays with the official rules, with the exception of the "catch" mechanism for playing WildDraw4 (which I chose not to implement).

@user1873 I intended that to be the code for when I have some cards that don't go, and a wild card that I want to save. If I have multiple wild cards I should play them in either the block labelled"I'm about to be trounced" or the block labelled "try to save a black card for the end". Let me know if you want me to check your code (or if you're using a documented rules engine I might be able to code it for you?)

Having thought about it a bit I realised that the language isn't the main barrier to coding an ai player, it's the interface that I'd need to know. Anyway, I'm happy for you to do it, I just thought my pseudo code might be easier for me to interpret!

I will code it up, I was just trying to point out some (possible errors) in your code. The interface only requires two functions, Play() returns the index of the card you will play next (-1 means draw). Callcolor() returns an enum that represents on of the 4 colors (wilds are considered to not have a color). The buggy one linked in the OP will show you what else you have access to (I can add additional info if you need it). The problem I see is that you said your rules flow top to bottom, left to right. Your second to last rule has you playing all cards except wilds (should I comment clarify)

The second to last rule is only meant to play those cards if they're actually valid. Looking through I've been a bit vague on how to proceed if none of the cards in an if block are valid. I think in those cases the execution should try the next else block. More complicated than I gave it credit for though!

My mistake, that line (Play skip turn, +2, change direction, 9-0, +4) will mean you are never keeping Wild Draw 4 cards. Your previous rule about keeping only one wild will ensure that you have at most one wild. The comment threw me"#I've got a wild card", but I understand now, since it doesn't make a difference if you don't have a wild, you have to draw anyway.

I play the largest number I can and save my draws, skips, and reverses for when they can be used against a winning opponent. I really don't worry about number variety. However, I try to keep a low number of high value cards in my hand, namely reverses, wilds, and skips, in that order, so if someone manages to win I don't give them too many points.
call color: No Strategy (color i have?)

play:
if hand has X or more Special Cards (SC),
    play SC(if possible): priority Reverse, Wild, Skip, (Wild Draw-4, Draw-2), 9-0
else if opponent has Y or fewer cards
    if opponent next and hand has Draw-2 or Skip (or Wild Draw-4)
        play Draw-2, Skip, (or Wild Draw-4)
    else if opponent last and hand has Reverse and (Draw-2 or Wild Draw-4)
        play Reverse
    else
        play 9-0, Draw-2, Skip, Reverse, (Wild, Wild Draw-4)
else
    play 9-0, Draw-2, Skip, Reverse, (Wild, Wild Draw-4)

Some clarification: you say you save draw, skip, reverse to be used against a winning opponent (What constitutes winning, fewer cards, or more points than anyone else but under 500)? Then you say you keep a low number of high value cards, how many 2,3,4? Which is higher priority when you have 2 special cards, a Blue9 or BlueReverse?

I have added some pseudo code to clarify some points. The default behavior as you explained it is to play the highest point card, then Special cards. Priority is left to right always, so if you have a Draw-2 and Reverse in the same color, you will play the Draw-2. (Wilds played as a last resort). I need values for X & Y, and I assumed you wanted to reduce point cards over attacking a winning player (assumed cards in hand defines winning). Made some other assumptions if the winning player isn't adjacent to return to default behavior.

I don't know whether you're still running your experiment, but lately I've been trying various strategies for the phone-based version of Uno that I have and one that I've been doing is, when the color is C and I have X cards of C and Y cards of another color, D, if Y is greater than X, I go ahead and switch. It seems like it increases my opportunity of a string of cards being played versus staying in the same color and getting stuck earlier, assuming the color doesn't change on its own.

Can you expand this so that it's a more-complete strategy of what you do and when? Deciding when to change your color is an important part of the game, but what do you do the rest of the time?

I don't have a fully-fledged strategy, but basically, my question is along the lines of, "If the color is red and I have 3 red cards and 3 green cards, one of which matches the current number", am I better off playing red or green? My immediate impulse is to stick with the color we're on, but I can see the flip-side. Either way, you're on a color that you have cards for. If the value of N were 1, you're facing having to change color either way.

The question is asking for complete (or complete-ish) strategies; as it stands, this is an incomplete answer. Can you take a little time and answer the other parts of the question? Also, the other answers here give a decent idea of what to think about. Don't worry about having a provably-correct strategy, just fill in the rest of the parts of the question with the plays you tend to do when those situations come up.

Your color strategy seems to bring up something that I haven't seen anybody mention - playing colors that you know the next player (probably) doesn't have because they drew the last time that color was up to them.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
How many unique outcomes can be made from the 12 river tiles in Carcassonne?
I have been pondering this question for some time now and it's a bit out of my scope to solve it. I am curious to know how many possible arrangements are possible for the river 1 expansion for Carcassonne.
The rules for playing the river are as follows: The source tile is played first, The lake tile is played last, and If two river bends are drawn in sequence they must have opposing orientation.
I understand the following: The first and last tile played will not factor into the counting so we just look at the 10 tiles inbetween. Each tile has 2 orientations and there are 8 unique tiles, 1 repeated corner, and one repeated straight. We must also exclude possibilities that become unplayable when the river curves in onto itself.
I posted an image of all the tiles from the river expansion.
My preliminary guesswork at counting is
(2^8)10!/2!2!
My rationale
10!/2!2! Because order of selection matters and repition tiles are excluded by dividing by 2!
2^8 Because each tile can be place in 2 ways( the 2 straight tile are not included because they are not unique)
I know this is wrong. It's just my first guess at it, and it has not excluded possibilities where the river curves into itself and creates an unplayable game. Any assistance would be much appreciated, thanks!

Are you counting artistic uniqueness, or mechanical uniqueness? (ie would reversing the double city river in the upper left count as a new setup?  Would swapping the two plain straights?)

It seems this configuration is invalid, since it has two U-turns: http://www.modernjive.com/carcassonne/carcassonnetheriver.pdf

Arcanist Lupus, I was more curious about mechanical uniqness. So, as you mention rotating the double city would would not create a unique playable board and neither would swapping the plane straights.

Glorfindel, you raise a very good point. I wanted to post a picture to show an example of all the tiles available in the river expansion (1), but I realise this is a bad example as it demonstrates a board which breaks the rules. Thanks for pointing that out!

As mentioned in the comments, I think the U-turns of the river in your example board are invalid; see (this version of) the rules. If, as you say "We must also exclude possibilities that become unplayable when the river curves in onto itself.", the Java program at the bottom will calculate all possible boards, with the caveat that it distinguishes between the two straights with two grass borders and between the two bends with two grass borders (we can correct for those later). Here's an example board it generates:

The total is a whopping 1,715,761,152 boards, where I've already assumed the source always flows to the right (otherwise, you'd just get a rotated version of the full board). But some of those are equivalent according to your definition:

We can always swap the two bends with two grass borders
We can always swap the two straights with two grass borders
We can always rotate the first of those straights 180 degrees
We can always rotate the second of those straights 180 degrees
We can always rotate the straight with two town borders 180 degrees
We can always rotate the straight with two road borders 180 degrees

This means that we have to divide the total by 26, so there are 1,715,761,152 / 64 = 26,808,768, almost 27 million different (full) boards according to your definition.
The Java program is as follows:
package com.stackexchange.boardgames;

public class CarcassonneRiverSimulator {
    private static Tile endTile;
    private static Tile[] tiles;
    private static int numberOfBoards;

    public static void main(String[] args) {
        // as shown in https://boardgames.stackexchange.com/q/43479, North -> East -> South -> West
        Tile startTile = new Tile(new Border[] { Border.Grass, Border.River, Border.Grass, Border.Grass }, false);
        tiles = new Tile[] { startTile,
                new Tile(new Border[] { Border.Town, Border.River, Border.Town, Border.River }, false),
                new Tile(new Border[] { Border.Grass, Border.River, Border.Grass, Border.River }, false),
                new Tile(new Border[] { Border.Road, Border.Road, Border.River, Border.River }, true),
                new Tile(new Border[] { Border.River, Border.Grass, Border.Grass, Border.River }, true),
                new Tile(new Border[] { Border.Grass, Border.River, Border.Grass, Border.River }, false),
                new Tile(new Border[] { Border.Town, Border.River, Border.Road, Border.River }, false),
                new Tile(new Border[] { Border.Grass, Border.River, Border.River, Border.Grass }, true),
                new Tile(new Border[] { Border.River, Border.River, Border.Town, Border.Town }, true),
                new Tile(new Border[] { Border.Road, Border.River, Border.Road, Border.River }, false),
                new Tile(new Border[] { Border.Grass, Border.River, Border.Road, Border.River }, false) };
        endTile = new Tile(new Border[] { Border.Grass, Border.Grass, Border.Grass, Border.River }, false);

        // Start with the start tile @ 0,0 in the indicated direction
        // x increases to the East, y increases to the South
        startTile.position = new Position(0, 0, North);
        Position nextRiver = new Position(1, 0, West); // i.e. the next tile needs to be at (1, 0) and needs to have a
                                                        // river in
        // the West position

        // Check next tile (recursively)
        nextTile(nextRiver, null);

        System.out.println(numberOfBoards + " valid boards found.");
    }

    private static void nextTile(Position nextRiver, Integer invalidNextRiverDirection) {
        boolean nonPositionedTileFound = false;
        for (Tile tile : tiles) {
            if (tile.position != null)
                continue;
            nonPositionedTileFound = true;
            tryToPlaceTile(nextRiver, tile, invalidNextRiverDirection);
        }
        if (nonPositionedTileFound)
            return;
        // Place end tile (this can fail because one of its grass borders blocks a town or road)
        tryToPlaceTile(nextRiver, endTile, invalidNextRiverDirection);
    }

    private static void tryToPlaceTile(Position nextRiver, Tile tile, Integer invalidNextRiverDirection) {
        // Try to add this tile to the mouth of the river in any of the directions
        // (North = don't rotate, East = rotate 90 degrees clockwise, etc.)
        for (int rotate = North; rotate <= West; rotate++) {
            int riverDirection = (4 + nextRiver.direction - rotate) % 4;
            if (tile.borders[riverDirection] != Border.River)
                continue;

            // Check other borders
            boolean valid = true;
            for (int border = 0; border < 4; border++) {
                if (border == riverDirection)
                    continue;
                int direction = (border + rotate) % 4;
                int x = nextRiver.x + getDx(direction);
                int y = nextRiver.y + getDy(direction);
                for (Tile otherTile : tiles) {
                    if (otherTile.position == null || otherTile.position.x != x || otherTile.position.y != y)
                        continue;
                    if (otherTile.borders[(6 + direction - otherTile.position.direction) % 4] == tile.borders[border])
                        continue;
                    valid = false;
                    break;
                }
                if (!valid)
                    break;
            }
            if (!valid)
                continue;

            // Find next river position
            Position nextNextRiver = null;
            for (int border = 0; border < 4; border++) {
                if (border == riverDirection)
                    continue;
                if (tile.borders[border] != Border.River)
                    continue;
                int nextRiverDirection = (border + rotate + 2) % 4;
                if (invalidNextRiverDirection != null && invalidNextRiverDirection == nextRiverDirection)
                    break;
                tile.position = new Position(nextRiver.x, nextRiver.y, rotate);
                nextNextRiver = new Position(tile.position.x - getDx(nextRiverDirection),
                        tile.position.y - getDy(nextRiverDirection), nextRiverDirection);
                break;
            }

            if (tile == endTile) {
                // Valid board found
                numberOfBoards++;
            } else if (tile.position != null) {
                // Check next tile (recursively)
                nextTile(nextNextRiver, tile.isBend ? (nextRiver.direction + 2) % 4 : null);
            }

            // Reset position
            tile.position = null;
        }
    }

    private static enum Border {
        Grass, River, Road, Town
    }

    private static final int North = 0, East = 1, South = 2, West = 3;

    private static int getDx(int direction) {
        return direction == West ? -1 : direction == East ? 1 : 0;
    }

    private static int getDy(int direction) {
        return direction == North ? -1 : direction == South ? 1 : 0;
    }

    private static class Position {
        public Position(int x, int y, int direction) {
            this.x = x;
            this.y = y;
            this.direction = direction;
        }

        public final int x, y, direction;
    }

    private static class Tile {
        public Tile(Border[] borders, boolean isBend) {
            this.borders = borders;
            this.isBend = isBend;
        }

        public final Border[] borders;
        public final boolean isBend;
        public Position position;

        @Override
        public String toString() {
            StringBuilder builder = new StringBuilder();
            int direction = position == null ? 0 : position.direction;
            for (int border = 0; border < 4; border++) {
                if (builder.length() > 0)
                    builder.append(", ");
                builder.append(borders[(4 + border - direction) % 4].toString());
            }
            builder.insert(0, "[");
            builder.append("]");
            return builder.toString() + (position == null ? "" : " @ (" + position.x + ", " + position.y + ")");
        }
    }
}

Wow, that is awesome! Thanks for all the work you put into your solution! I really appreciate it. My wife and I are big fans of the game and have played many times now, and I began wondering what the probability would be of laying the same unique river twice or more. I am seeing now with a number that big there is a high chance we will never play the same river twice!


text:
Looking for Card Game With Streaks of Ashes on the Face
I am looking for a specific Card Game that my Grandma and Grandpa both played when they were younger.
They don't remember the rules, but it appears that the defining feature was that, after a player would win a round, they would take some ash from a fireplace and make a streak on their face with it.
I don't remember what they said the name is, but I do remember that it is a semi-inappropriate word.
Any kind of info (name, rules, etc.) would help!
Thank you so much!
Notes:
It is not "Oh, Hell"

Was it played with a traditional deck of cards?

To the best of my knowledge, yes.

I was thinking this was "Oh, Hell" but the ashes don't appear in any of the variants I could find.

What about "Oh Hell" makes that a reasonable guess? I wouldn't say that players win a round in that game.

Not necessarily win a round, but win a hand, etc.  I know it's not "Oh, Hell" because we also play that with them and they didn't say that that was the game.  I also remember that it had some other name.

@TheChaz2.0 I thought that based solely on the description of what the questioner remembers of the name of the game (many families consider "hell" an inappropriate word for/around children).

Ah, that makes sense.

It looks like a game that is known in dutch as black peeter (zwarte pieten), but it has several names.

In Greece the game is called "mu(n)tzuris" (μου(ν)τζούρης, "smudged, smutted"), because winners used to smudge the loser with soot.

The goal of the game was to remove matching pairs. Players moved one card to the player to the left, receiving one from the left. But there was one unmatched card. So the one left with this card lost and got ash or some other stuff that was black and hard to remove from their face.

Might be it.  The Wikipedia article mentions that one variant is called "jackass", which might be considered inappropriate for children in certain circles.

It's possible they were playing a variant of a game commonly called "Shithead."  This is a game that is conceptually similar to Uno, where the goal is to get rid of all one's cards, and variants often include special rules for various card values, such as reversing order of play, drawing extra cards, and so forth.
One core mechanic of the game is that the last person with a card remaining in their hand is designated the "shithead" and, at a minimum, has to deal the next hand, but variants often have the shithead paying some kind of forfeit -- fetching drinks for everyone at the table, or very possibly streaking ashes on his face.


text:
Objectives in collectible card games
The majority of deck building card games use the following winning condition:

You and your opponent are the central figures on the battlefield, and the game ends as soon as one of you (or both) is killed.
You start the game with some positive amount of life that goes up and down (usually down) as you battle.
Whenever your life total is at or below 0, you are dead and you lose.

A slight variety of that is when there is no central figure and you have to destroy all your opponent's creatures to win.
I was able to find only two games that use different winning conditions: Gwent the Witcher and Ascension: Chronicle of the Godslayer. Could you please name some more?
In particular, I'm interested in the following condition: you and your opponent start at 0 points, you earn (or lose) points as you play and whoever has more points at the end of the game wins. (Both Gwent and Ascension seem to be examples of this mechanic.)

Hi, can you add some more information about the winning conditions of Gwents. So you can get answers from people that do not know the game.

This seems like a list question, which might be off topic, but some examples might be the Lord of the Rings game (you win if you reach the end of the map; you lose if your ring-bearer dies) and Netrunner (which is completely assymetric)

Ascension is not a CCG, and it's not 2p-only. Also, there are tons of games with different win conditions. For a strictly card game, look at Innovation.

For the record I have played plenty of deck building games where killing your opponent is not the goal or a feature of the game. In truth when you start looking there are lots of different win conditions based on the theme of the game.

They are not CCGs strictly speaking but Fantasy Flight Games' Game of Thrones Living Card game and the new Keyforge have very different victory conditions.
The latter has Aember, basically victory points, that can be won, lost and stolen. They are automatically used to unlock keys at the beginning of you turn. When you unlock 3 keys, you win. The game still uses, creatures, artifacts and instants, but all serve to earn Aember.
Killing creatures only slows your opponent down. I like this system a lot!

Pretty much every card game from Fantasy Flight has a different victory condition.
Android: Netrunner is played to 7 points.
Legend of the Five Rinds is won militarily by destroying provinces rather than dealing damage, and you can also win on Honor.
Warhammer 40,000: Conquest was a different variant of fighting for provinces, and the central figure (the warlord) was an in-game creature that could be killed (you lost if your warlord died).
Arkham Horror: The Card Game is a game where you play co-op missions and have customization decks of equipment.
The list goes on.


text:
How will spells resolve MTG
So I have 1/2 creature, opponent uses shock to kill it, then I answer with my giant growth and opponent responds with another shock. Will my creature survive or die?
which spells will resolve first.
I cast giant growth on 1/1 creature and enemy responds with shock. Will my creature take 2 damage first because shock is on top of a stack or will giant growth give +3/+3 to that creature until shock hits it?

Its not duplicate i wasnt able to find answer on that post

@SharaShara out of curiosity are you playing in paper magic or online in Magic Arena?

paper  also i am a beginner

@SharaShara Could you explain why the linked to question/answer didn't answer your question?  From my perspective it does, but I'm not a beginner either....

english isnt my main language and i cant understand it very well so i want a simple answer will my creature die or survive

@SharaShara your question is covered in the linked duplicate answer, but if you would like a bit of explanation to your specific misunderstandings you can hop into chat.

i cant "hop in " because i havnt enough reputation

@SharaShara you should still be able to read chat, even though you don't have the rep to answer

ok.. just tell me will my  1/1 creature die or survive if i cast giant growth and my enemy responds with shock if you cant answer just tell me and i'l search different forum

I spelled out the interaction for you in chat have a look there. Comments here isn't a good spot for answering your question as they will be cleaned up and deleted shortly.

Thanks, sorry for being rude ( if i was rude idk :D )

@SharaShara No problem, welcome to the site. Once you get a bit more rep (20) you will be able to participate in chat as well.

Your creature will die, if your opponent plays correctly.
Here's your opponent's correct line of play in detail.
Opponent plays Shock.  Shock is on the Stack.  Your opponent decided to do nothing else (also known as "passes priority") and you get a chance to respond.  You do, by casting Giant Growth.  You have nothing else to do, so you pass priority.  Your opponent gets a chance to respond before any spells resolve.
The stack is now:

Giant Growth
Shock

Your opponent casts Shock, and passes priority, and the stack looks like:

Shock
Giant Growth
Shock

You pass priority (i.e. you have nothing else you can do.)  Spells resolve one at a time, the most recently cast spell resolving first.
Your opponent's Shock does two points of damage to your creature.  Your creature dies, before your Giant Growth resolves.


text:
Babylon B Stage 2 - Purchasing neighbor's resource
On the 6th turn, the Babylon player builds their second stage wonder. Their last card in hand requires a Cloth.
Babylon's neighbor built a Loom on their 6th turn. Can the Babylon player, on their 7th turn, purchase Cloth from that neighbor?
This is not a duplicate question. My question specifically asks whether the Babylon player may benefit from the 6th card build by Babylon's neighbors for the 7th card and 7th card only.
All other answers talk about the 7th card benefiting from the 6th card of the Babylon player, or whether the usage state of Babylon's and neighbors resources may be reset for the 7th card's use.
(Also, can does the Babylon player receive gold earned from neighbors between their 6th and 7th card?)

@Caleb Welcome to Board & Card Games. This question has previously been answered. Please use the link above to find the answer to your question.

To those voting to close based on the linked question, these seem like different questions. The linked question is asking whether the player can use the same resource twice for Babylon on "turn 6," while this question appears to be asking whether the player can purchase a resource from a neighbor from a resource card that was built on turn 6, prior to the last card being played by the Babylon player.

Thanks SocioMatt, I asked this question because the other answers do not address this point specifically.
@Todd and Ginji, even the second answer in "Can a resource card be used more than once in a turn when allowed to build more than one structure?" makes no mention specifically about whether the Babylon player may benefit from the 6th card built by their neighbors for their 7th card (and 7th card only).

I'm confused, and a bit insulted, that the conversation above is going on hours after I gave the definitive answer. I have added the rules booklet page numbers for those who despair of locating the cited rules.

The second answer in the other thread added 2 hours after my question was asked, mentioned this: "You can build a resource card in the 6th turn, and use it to build the last card (same if a neighbour builds it)."
It only has 1 vote now, but if accepted, that would mean that the answer to my question is "Yes". Could someone confirm and answer on my question too?

If an answer on a different question is confirmed to be an answer to this question, it is absolutely a duplicate, and should be left closed as redirecting there, possibly with a comment stating which answer worked.

@Nij, but the question you all are claiming this is a duplicate of isn't even asking the same thing. The answer that works, wasn't even answering that question. The two questions are clearly NOT duplicates. Just because there exists an answer that works doesn't mean the two questions are duplicates. Please read carefully and in full. There is no way anyone who has read both questions can claim this is a duplicate question. BTW, this is the answer that works: https://boardgames.stackexchange.com/a/43721/25263.

Actually, that's exactly what being a duplicate means, and hence the closure. "Questions may be duplicates if they have the same (potential) answers. This includes not only word-for-word duplicates, but also the same idea expressed in different words."

No. The Babylon player does not get a 7th turn. The wonder allows the player to use both cards on his 6th turn.
"Clarification :
- during the sixth turn, the player can therefore play both cards they have
in hand." Rules to 7 Wonders, page 9.
All actions are simultaneous, so the loom would not exist when the 7th card is played.
"2. Action
Once every player has selected his or her card, they perform their action
simultaneously." Rules to 7 Wonders, page 5.

Why the down votes. My answer addresses the question and quotes the relevant rule.

The first quote is often questioned as it is too ambiguous. It had led to the significant discussion in the community and a final clarification by the creator regarding his intent - it is actually to be treated as an additional turn.
The second quote is a very general rule describing the basic operations in the game. As clarified multiple times, the 2 cards to be played due to Babylon B are NOT simultaneous.
Basically, those two rules are too vague, which is why we ask for clarification. Here, you are quoting them as is, disregarding all the discussion that has gone on.

But you are right, for my specific question, looking plainly at these two rules, the Babylon player does not get a 7th turn. But neither should they get to use the gold from discarding the 6th card, the resources generated from the 6th etc. Which is why, it is not a useful answer.

The two rules are clear. The designers "clarification" directly contradicts one of them, so it was not a clarification, but rather an informal change in the rules. It has no more standing than any other optional rule. Unless the players have agreed beforehand to use that variant, the rules as written should apply. If you look at the discussions concerning this, no one thinks the rules were ambiguous; they just didn't like the results.

Then clearly the designer made a mistake with his original wording of the rules. I want to play it the way he envisions it, also, the way that makes the most sense, and is the most balanced and most importantly, intuitive and fun.


text:
Splice and Arcane combo
What are the current rules for spliced spells? Can they still be spliced again as long its mana cost is paid? or each spell can be spliced only once? If they an arcane spell can be spliced only once then if it goes to the graveyard the counter is reseted and be spliced again?
For a Desperate Ritual + Past in Flames combo
EDIT: Thanks for your response everyone.
Now is clear to me that cards that fill the requirements can be spliced only once and as long they are in your hand.

I'm voting to close this as unclear. It appears to be asking many disparate things, all in very unclear ways, and the core issue (splice + flashback) is not even explicitly asked about in the question. Instead this should be revised to assert a clear scenario of what you are requesting to ask if it is possible.

The rules for splice onto arcane (currently the only form of splice, and described in CR 702.46) are as follows:

While you are casting an arcane spell, if you have a splice onto arcane card in your hand (hereafter called a splice card), you may reveal the splice card.
If you do, pay the splice cost on the splice card.
The arcane spell gains the effects of the splice card.

Nothing happens to the Splice card. It stays in your hand. The original card resolves (plus the splice effects) then, usually, winds up in your graveyard.
You cite Desperate Ritual + Past in Flames as a combo. You cannot splice onto Past in Flames because it is not arcane. I hope you are instead just planning on using Past in Flames to re-cast an Arcane card from your graveyard.
An arcane spell is a spell with the Arcane subtype, i.e. one of these: t:arcane. These cards all have a type line that reads “Instant — Arcane” or “Sorcery — Arcane”. This means they have the Arcane subtype. This is just like how a Creature may be a Zombie, and cards may care about Zombie cards. The exact same way, splice onto arcane cares about Arcane cards.
If you do happen to cast an Arcane card from your graveyard, such as via Past in Flames, you can still splice Desperate Ritual onto it if Desperate Ritual is in your hand at the time you cast it.

I don’t think you addressed the question of if you can use the same splice multiple times.

(You can’t, but it’s not clear to me why that is from the comprehensive rules.)

From the Gatherer Rulings:  "You reveal all cards you intend to splice at the same time. Each individual card can be spliced only once onto any one spell."

@ArcanistLupus Yeah, where I'm getting hung up though is why that is true from the comprehensive rules. I guess it comes down to what the timing window for "as you cast a spell" is...

@Gendolkari Fair point.  The closest I could find was in 601.2b: "...If the player wishes to splice any cards onto the spell (see rule 702.46), they reveal those cards in their hand. ..."

Terminology nit-pick: It's splice onto arcane, not into.

So you can't splice from your graveyard using the flash effect because you can't reveal them from your hand?

@Randoseru That's correct. If you have a card in your graveyard with the ability "Splice onto arcane", then it's in your graveyard, so you can't reveal it from your hand, and thus it cannot be spliced.

@Randoseru Is that what your question is about basically, splicing from the graveyard by giving the splice card flashback?

@doppelgreener Yes, using the flash + splice combo the idea was make a huge mana pool and finish the opponent.

@GendoIkari You can only splice once because the event of casting a spell happens only once (per spell). 702.46a "You may reveal this card from your hand as you cast a [subtype] spell".

@Hackworth Well 601.2b makes it clear, but if the rules for casting a spell didn't include specifically when a splice card is revealed and used, I would have no idea from "as you cast a spell" when exactly you would do it, because casting a spell is a long, multi-step process, during which there would be many different opportunities to do things "as you cast a spell". Casting a spell isn't like entering the battlefield, which is a specific moment in time.

FWIW I've decided to vote to close the question as unclear.

Sorry to make a seemingly trivial edit, but Magic rules are difficult enough to manage the terminology. No hard feelings I hope.

@corsiKa That's fine. Thanks for that. I've just not revised this since I'm not even sure what the question is doing at this point so I am not sure what I should revise this to say—or it seems to be doing a great many things but not expressing them clearly, or if it is only doing one thing, it is not being clear about that.

@GendoIkari You were wondering where exactly the CR determined how often you may splice per spell, not exactly at which point of the spell casting process. Just because casting a spell is a multi-step process does in no way mean you can splice the same card as often as you want, or do other things multiple times that you do "as you cast x" (which btw is a fairly common wording).

@Hackworth Fair; I think 614.5 is actually the rule that makes it clear that you can only use it once. It's just not clear from the Splice section of rules; but the general rules regarding replacement effects is clear.


text:
Dragonfire - Gorgon Encounter
In Dragonfire, the Gorgon Encounter has the following Tripwire:

Terror: Can only play one card; cannot Assist.

Say that the '5' level of the damage track was already cleared, and on my current turn I then clear the '2' level. Can I play one card from this point, or is the Terror retroactive?

Perhaps your question is more clear to players of the game, but does clearing a level remove a card/effect from play?

@ryanyuyu No, it clears one level from the encounter's damage track. I'll try to make my question more clear

None of the Tripwires are retroactive, but as per the turn order you are not able to play cards after the Gorgons Terror tripwire has triggered.
This is also detailed in the Errata and FAQ:

Q: Is the Terror Tripwire keyword an ongoing effect?
A: Yes, Terror is an ongoing effect once it has been activated.
However, remember that the Apply Damage phase occurs after
the Play Cards phase, so if you’re going to trip the Terror Tripwire
on a turn, you’ll get to play cards as normal on that turn, since the
keyword won’t come into effect until the Take Damage phase of
your turn.


text:
Does Curse of Opulence give its controller tokens when someone else attacks?
Let's say player A casts Curse of Opulence on player B. Then, player C attacks player B. I claimed that player A and C each create Gold tokens, but my friends agreed that only player C creates a Gold token. Was I wrong? I think that greatly decreases the value of the Curse.

You are correct, players A and C each create a Gold token.
The ability "Whenever enchanted player is attacked, create a colorless artifact token named Gold" applies to the player that controls Curse of Opulence, which is player A in this case.
The other part of the ability, "Each opponent attacking that player does the same" makes it so that player C also gets a token.

303.4e An Aura’s controller is separate from the enchanted object’s controller or the enchanted player; the two need not be the same.

The player who controls Curse of Opulence is also the controller of the triggered ability:

112.8. The controller of an activated ability on the stack is the player who activated it. The controller of a triggered ability on the stack (other than a delayed triggered ability) is the player who controlled the ability’s source when it triggered [...]

And the controller of the ability is the one that carries out the instructions, including to create the token:

608.2c The controller of the spell or ability follows its instructions in the order written.


text:
Can Aquamoeba beat Glory Seeker with discards?
Can Aquamoeba beat Glory Seeker if the Aquamoeba owner discards one or more cards during the fight?

Discard a card from your hand: switch Aquamoeba's power and toughness until end of turn. 1/3 creature

2/2 creature - human soldier

Depends on your definition of "beat."

Well, i want possible scenarios. If you discard 0, 1 or 2 cards, what happens in each case (who dies and who survives and why) ?

It used to be the case that you could do this:

Declare attackers and blockers
Activate the Aquamoeba's ability
Resolve the stack
Put 3 combat damage on the stack
Activate the Aquamoeba's ability again
Resolve stack

This would cause the Aquamoeba to have 3 power when damage was assigned but have 3 toughness when damage was resolved, killing the 2/2 but leaving the Aquamoeba alive.
However, changes to the combat rules for Magic 2010 were made that specifically prevented this. Now damage does not use the stack and is assigned and applied in one step, so the Aquamoeba can be either 1/3 at the time (and both survive) or 3/1 at the time (and both die).

You should take the time to read up on how the Stack works.
Unless stated otherwise on the card, all activated abilities can be played at anytime, identical to an instant. This means you can activate Aquamoeba's ability during combat, and due to the way the Stack works Aquamoeba's ability will take effect before combat damage is dealt. Therefore using Aquamoeba's ability will result in both itself and Glory Seeker dying.

Yup it can. Card abilities can be activated like instants - therefore can be activated at any time of play. Although both creature would die because it does not have first strike.


text:
Does Winds of Abandon, overloaded, cause the player to search their library multiple times or just once?
If I cast Winds of Abandon for its overload cost which says,

Exile each creature you don't control. For each creature exiled this way, its controller searches his or her library for a basic land card. Those players put those cards onto the battlefield tapped, then shuffle their libraries.

and an opponent has 5 creatures, does that opponent search their library five times for 1 basic land or search once for 5 basic lands?

Is there a reason the distinction matters to you?

@John this makes a difference when the owner of Winds of Abandon also controls an Opposition Agent for example.

@bautista I am not seeing why this matters for Opposition Agent.

@John you're right! Aven Mindcensor works as an example though.

@John I had a Winds of Abandon and Ob Nixilis, Unshackled combo in mind; thinking Ob would ping someone for like 50 dmg

Just once - multiple searches that occur before shuffling are treated as a single search.

701.19h An effect may instruct a player to search a library for one or more cards more than once before instructing a player to shuffle that library. This is the same as a single instruction for that player to search that library for all those cards. The player searches that library only once.

Since Winds of Abandon instructs the player to potentially search their library multiple times for a basic land and then shuffle, it should be treated as searching the library once for multiple basic lands.


text:
Activating Demonic hordes’s ability in response to it’s upkeep cost
Can I activate Demonic Hordes’s ability in the upkeep in response to having to play BBB?

Yes, you can do this. When your upkeep begins, the ability will trigger and go on the stack. At that point you will get priority and can activate activated abilities. When that triggered ability resolves, you will still have to pay the mana or else you'll sacrifice a land of an opponent's choice. The "tap Demonic Hordes" part of the penalty just won't hurt you because it's already tapped.

Upkeep Step

503.1. The upkeep step has no turn-based actions. Once it begins, the active player gets priority. (See rule 117, “Timing and Priority.”)

503.1a Any abilities that triggered during the untap step and any abilities that triggered at the beginning of the upkeep are put onto the stack before the active player gets priority; the order in which they triggered doesn’t matter. (See rule 603, “Handling Triggered Abilities.”)