text:
Baral, Chief of Compliance doubt
Suppose I play Baral, Chief of Compliance with red mana available. The opponent responds with Lightning Bolt killing my Baral.
Can I continue to combo getting a cost reduction from Baral on the stack or does the cost reduction end with the 3 damage from the Bolt?
I believe it does because Baral hasn't resolved yet. In that case, is it a different situation if the opponent targets Baral after it has resolved, for example the following turn?

How does you having red mana matter for your playing of Baral?

@Andrew I believe he just meant to say that he could afford to cast other spells in addition to Baral.

@ Andrew Yes, I'm sorry if I didn't make that clear but I meant that if I have 2 Rituals, Manamorphose, Gifts Ungiven and Baral in hand with U/R, U/R and R available as my turn begins. Can I play the Rituals for 1R after the opponent's Lightning Bolt has targeted my Baral netting me 5R in my mana pool and then play the instants and sorceries with the cost reduction given by Baral? Assuming I play Gifts for the classic pile and get given Manamorphose and Past in Flames, is it possible to play the Manamorhphose followed by the PIF and continue or is it too late to play a sorcery now? I think so

If you play it right, you can cast one sorcery and a number of instants at a discount.

Two key points before we start:

Baral must be on the battlefield to be targeted by Lightning Bolt.
Baral must be on the battlefield to provide its discount.

Lightning Bolt targets a creature or a player. "Creature" means "creature permanent", which means "creature card or token on the battlefield". As such, Baral can only be targeted by Lightning Bolt when it's on the battlefield. In other words, Baral couldn't have been targeted by the Lightning Bolt while it was still on the stack.
If your opponent specifically said they cast Lightning Bolt in response to Baral and proceeded to target Baral, they made a mistake.
If they simply said they were casting Lightning Bolt, they were actually proposing the following shortcut:

You pass priority to let Baral resolve.
You pass priority after Baral resolves.
They cast Lightning Bolt.

You don't have to accept the entire shortcut. For example, let's say one of the spells you wanted to cast is a sorcery. You could let Baral resolve, and step in to cast the sorcery instead of doing step 2. (See [CR 719] for more on shortcuts.) The following would happen instead:

You pass priority to let Baral resolve.
You cast a sorcery (at a discount).

Now, they have priority. Let's say they cast Lightning Bolt at this point. (They don't have to because you shortened their shortcut.) The stack:

(top) Lightning Bolt
(bottom) Your sorcery

At this point, Lightning Bolt hasn't resolved, and thus hasn't dealt its damage yet. That means that instants cast in response to Lightning Bolt will benefit from the discount.

(top) ...
Your Instant #2
Your Instant #1
Lightning Bolt
(bottom) Your Sorcery

(You could also cast the instants one after the other instead of in response to each other. That would actually be a bit more natural.)
Eventually, after Lightning Bolt resolves and before anything else happens, Baral will be moved to the graveyard and will no longer provide its discount. The continuous effects from static abilities apply at all times that the permanent generating it is on the battlefield or the object generating it is in the appropriate zone. And not a moment longer.[CR 611.3b]

If I play Baral with red mana available, the opponent responds with Lightning Bolt killing my Baral

Impossible. Your opponent must wait for Baral to resolve if they wish to target it with Lightning Bolt, so they can't cast the Lightning Bolt in response to you casting Baral.

can I continue to combo getting a cost reduction from Baral on the stack or  I've got a feeling it does because Baral hasn't resolved yet.

Baral static ability only works when Baral is on the battlefield. If Baral hasn't resolved yet, it doesn't provide a discount.

does the cost reduction end with the 3 damage from the Bolt.

Yes. It happens when Baral moves to the graveyard, which happens immediately after the damage is dealt.

This cannot happen the way you describe. You cannot kill Baral, Chief of Compliance, or any creature, with damage while he is still on the stack, creatures on the stack can only be countered, spells like Lightning Bolt can only target creatures on the field. Also you do not get Baral's cost reduction benefit while he's still on the stack, only once he resolves.
Once Baral resolves, you have priority (assuming you didn't somehow flash him in and it's someone else's turn), so you get the first choice of playing a spell, this can be any spell type, so you can choose to cast a sorcery at reduced cost here. Your opponent then has his first chance to cast Lightning Bolt to try and kill Baral, Lightning Bolt will go on the stack like every other spell does, the damage does not happen and Baral does not die as soon as they cast it.
Just like your opponent could respond with lightning bolt to that, you can respond to lightning bolt with a spell of your own, at this point the stack isn't empty so you can only cast instants or cards with flash. The instant you cast can be something to counter the lightning bolt (you are playing blue after all) and save your Baral, or something that will make Baral stronger and let him survive the bolt, or anything else you want.
It's a common shortcut in magic to just resolve spells as they are cast, but the way the stack really works is the last spell put on the stack only resolves once all players have passed priority, all players have had a chance to react to the spell being played and chosen to do nothing.


text:
Sac outlet, Cyclonic Rift overload, & Chronozoa
Say I have a Chronozoa with no counters and a free sacrifice outlet on the field when an opponent overloads Cyclonic Rift. If I were to sacrifice the Chronozoa in response, what happens? Will I create the tokens that are copies of it before or after the CR Overload resolves?

Your Chronozoa's ability would resolve first, and you would lose the tokens you got to the opponent's Cyclonic rift.
Whenever an ability triggers or is activated, is goes on top of the stack, and the stack resolves from top to bottom.
So, assuming you both pass after each step:

Opponent casts Cyclonic Rift, stack has just Cyclonic Rift
You respond by activating something that lets you sacrifice Chronozoa, Chronozoa's ability triggers and goes on top of the stack. (We will assume for now that the sacrifice didn’t add anything else to the stack, such as Ashnod's Altar).
Chronozoa's ability resolves giving you 2 tokens.
Cyclonic Rift resolves, returning tokens to your hand, which cease to exist because tokens can’t be in your hand.

There is no other time that you could sacrifice Chronozoa to get around this problem.
Note that in order to have a Chronozoa on the battlefield with no time counters requires something such as Stifle or Solemnity to stop you from sacrificing it when it lost its last counter.
Comprehensive rules:

405.1. When a spell is cast, the physical card is put on the stack (see rule 601.2a). When an ability is activated or triggers, it goes on top of the stack without any card associated with it (see rules 602.2a and 603.3).
405.5. When all players pass in succession, the top (last-added) spell or ability on the stack resolves.

source: Stack Exchange

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text:
An activated ability of a card that affects that card
If you have a Fleecemane Lion that is enchanted by Shielding Plax, and you pay to activate the ability Monstrosity 1, then would the creature fail to become monstorous and would not receive it's +1/+1?

Monstrosity does not target, so it is not affected by Shielding Plax. Something is only a "target" if the spell or ability uses the word "target" in its text, or the rules text for a keyword ability, or if it is an Aura spell, which is always targeted.

114.10a Just because an object or player is being affected by a spell or ability doesn’t make that object or player a target of that spell or ability. Unless that object or player is identified by the word “target” in the text of that spell or ability, or the rule for that keyword ability, it’s not a target.

Shielding Plax only prevents the creature from being targeted, so it has no affect at all on things like Monstrosity.

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text:
Can I transform Westvale Abbey during either assign attackers or assign blockers phase
Wanting to know if it is possible to sacrifice creatures during assign attackers or assign blockers in order to transform Westvale Abbey and use him as an attacker or blocker.  It would also require taping lands to generate the mana required or maybe artifacts.

Related: https://boardgames.stackexchange.com/questions/41689/warkite-marauder-and-the-timing-for-its-effect

You can also block with the 5 sacrifices and prevent the damage (and any lifelink) from the attackers if they dont have trample.

You can transform Westvale Abbey at several points of the Combat phase and potentially use Ormendahl as an attacker or blocker.
The Abbey's abilities other than its mana ability are normal activated abilities that require you to have priority.
There are 5 steps to combat:

506.1. The combat phase has five steps, which proceed in order: beginning of combat, declare attackers, declare blockers, combat damage, and end of combat.

During beginning of combat, everyone gets priority in APNAP order and you can transform Westvale Abbey. This is your last chance to transform if you want Ormendahl as an attacker this turn, and the other players will still get the opportunity to play instant spells and abilities after the Abbey has transformed.

Beginning of Combat Step

507.2. Second, the active player gets priority.

After everyone has passed priority, attackers are declared. If you are the attacking player, you can declare Ormendahl as an attacking creature if you controlled the permanent (Abbey/Ormendahl) uninterrupted since the  beginning of your turn, i.e. it has no summoning sickness. Directly afterwards, players again have the opportunity to cast spells and activate abilities. If you want Ormendahl as a blocker, now is your last chance to transform the Abbey.

Declare Attackers Step

508.1. First, the active player declares attackers. [..]
508.2. Second, the active player gets priority. [..]

Note that this means that as soon as the declare attackers step has started, anything that isn't already a creature cannot be declared to attack, and it's too late to transform the Abbey.
Next, blockers are declared (including another round of priority). Again, anything that isn't already a creature can't be declared a blocker.

Declare Blockers Step

509.1. First, the defending player declares blockers.
509.4. Fourth, the active player gets priority.

Finally, damage is dealt and combat ends.

"You can use mana abilities whenever you like" is inaccurate. If you don't have priority, the only way to activate mana abilities is if you are doing so as part casting a spell or activating an ability.

Minor nitpick, Ormendahl has haste so the summoning sickness thing doesn't matter.

@GendoIkari I agree with your nitpick, but am confused by your second sentence - if you don't have priority, how are you casting a spell or activating an ability to begin with?

@NuclearWang No one has priority while in the process of casting a spell; you had priority when you started to cast the spell. Also, I was slightly incorrect, you can also activate a mana ability when a rule or effect asks for a mana payment, which could be things other than your own spells/abilities (Brainwash, Mana Leak).

If you want to attack with Ormendahl, Profane Prince, you need to transform Westvale Abbey before the declare attackers step, either in beginning of combat step or sooner.
If you want to block with Ormendahl, Profane Prince, you need to transform Westvale Abbey before the declare blockers step, either in declare attackers step or sooner.
In the declare attackers step, players get priority only after attackers are declared, so it would be too late. Similarly, in declare blockers step, players get priority only after blockers are declared.

Declare Attackers Step

508.1. First, the active player declares attackers. [..]
508.2. Second, the active player gets priority. [..]

Declare Blockers Step

509.1. First, the defending player declares blockers.
509.4. Fourth, the active player gets priority.

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text:
The effect of wither
If Olivia Voldaren is enchanted with Fists of the Demigod and you activate the ability to deal damage to a target creature, does this damage come in the form of -1/-1 counters? If it does, and the target is a Spirit en-Kor, can the Spirit en-Kor redirect the -1/-1 counter?

Yes, Wither applies to all damage, not only combat damage.

702.79a Wither is a static ability. Damage dealt to a creature by a source with wither isn’t marked on that creature. Rather, it causes that source’s controller to put that many -1/-1 counters on that creature. See rule 119.3.

Yes, Spirit en-Kor can still use its ability to redirect the damage. Olivia Voldaren is still dealing damage, it's just that the effects of that damage are different than normal, so the Spirit's ability can be used. And when the damage is redirected, the source of the damage is still Olivia, so Wither still applies.

I cannot find any rule to back up my last sentence, though it is implied by the last ruling on Spirit en-Kor. Anyone know a CR that makes it clear that redirecting damage does not change the source (or type)?

Redirection of damage is a type of replacement effect so I imagine it would be handled similarly to multiple replacement effects on one event.

RE: CR rules 614.9. defines redireciton and replacement effects in general are outlined in 614 but it is pretty long

Re "Wither applies to all damage", See Puncture Blast

Re "I cannot find any rule to back up my last sentence", The source of the damage is defined by the effect ("Olivia Voldaren deals"), not by the rules. And nothing about Spirit en-Kor's redirection effect replaces the source.

@ikegami It is not clear to me from the rules alone that the effect dealing the damage is not the redirection effect.

The rules are clear: You follow the instructions of the ability, which is to change the creature to which the damage is dealt. Period. Replacement effects only replace what they say they replace. You won't find any rules that says they replacement effects don't changes things they don't say they change. The event being replaced is "Olivia Voldaren deals 1 damage to Spirit en-Kor", and Spirit en-Kor changes to what the damage is dealt, so the replaced event is "Olivia Voldaren deals 1 damage to ". There's absolutely no mention of changing the source in Spirit en-Kor.

As the name suggests, redirection simply redirects the damage. It doesn't prevent the damage then cause the redirector to deal damage.

"The next 1 damage that would be dealt to Spirit en-Kor this turn is dealt to target creature you control instead." It seems pretty clear to me that it's the same damage, with the same source and the same wither modification. The spirit just changes where the damage hits.

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text:
Canasta: Rules to pick up discard pile when frozen or not frozen
Is this a correct understanding of when you are allowed to pick up the discard pile?
If not frozen, you can pick up the discard pile if you can use the top card to make a meld from your hand OR to simply take the top card and put down and add to an existing meld on the table.
If the discard pile is frozen you can only pick up if the top card can make a meld from cards solely in your hand.  In other words if the top card is an 8 and you have an existing meld of 8's on the table but no 8's in your hand ( or wild card and 8) -you can't pick up the frozen discard pile?

You are mostly correct; except in your understanding of the wilds.
To determine if you are allowed to pick up the (entire) discard pile; follow these rules:

If the discard pile is frozen, you can only pick up the discard pile if you can immediately meld that top card along with 2 more of the same card from your hand. A wild cannot help you here; you need 2 natural matches, not including wilds. If you have never melded before; you need to also meet the minimum meld value (by melding whatever else you want from your hand at the same time). You can count the top card in the points for part of that minimum meld; but you cannot count anything else in the discard pile.
If the discard pile is not frozen, you can only pick up the discard pile if you can legally meld the top card of the discard pile. This could be melding it by just adding it to an existing meld; or melding it along with more cards from your hand (which could include wilds). There is no minimum meld to worry about, because if the discard pile is not frozen, you have already melded.

In either of the 2 cases, if you pick up the top card of the discard pile, you also pick up the entire pile.
The discard pile is frozen (for your team) if either there is a wild in the discard pile, or if your team has not yet melded at all.

Thanks. I know I sound like a dunce but I want to be crystal clear. If the pile is unfrozen you can take the pile if you can used the top card to make a meld out of the cards in your hand OR you can take the single top card ( and pile) and simply put that single card on an existing meld on the table. In other words if you want say the 8 that is the top card you don't have to have 8's in your hand?

That is correct. As long as you legally meld the top card (whether by adding to an existing meld or by combining with cards in hand), you can take the pile if it isn't frozen.


text:
Does Crystalline Sliver currently have hexproof or shroud?
Has the text of Crystalline Sliver been modified to have hexproof, or does it have shroud?  The reason I ask is the Crypt Sliver has

Tap: Regenerate target sliver

which the Crystalline would make unusable with its old wording.

The current text of a card (called Oracle text) is always available in Gatherer. Crystalline Sliver now reads:

All Slivers have shroud. (They can't be the targets of spells or abilities.)

Note that Wizards very strongly favors updating cards in ways that don't affect the way they work, but simply make them clearer and use more up-to-date terminology or phrasing (called non-functional errata). That's the case here: they just replaced the fully spelled-out ability with the keyword that means the same thing.

And in case the confusion here stems from Wizards previously changing cards specifically tied to the Hexproof ability (such as Vines of Vastwood) - even those cards have been changed back to their original meaning, not altering the way they work, as this answer suggests.


text:
Can resolution of an ability be used to trigger another ability?
Part of rule 117.10 says:

the resolution of a spell or ability doesn’t pay another spell or ability’s cost, even if part of its effect is doing the same thing the other cost asks for.

I am wondering if this means that the resolution of an ability can't be used to trigger another ability?

Can you give a possible example? as there are many possibilities from a simple resolution.

I have edited for clarity; I'm pretty sure I understand the question correctly. But @Bill, feel free to further edit yourself if I misunderstood something. Also, it would be helpful to provide a specific example of an interaction you are unsure about.

Yes, it can.
A simple example would be a "Tim" that taps for damage, like Prodigal Pyromancer. Combine that with any "Enrage" ability, like Bellowing Aegisaur. If Prodigal Pyromancer's ability targets Bellowing Aegisaur, then when it resolves, it will trigger Bellowing Aegisaur's ability.
Here's rule 117.10:

Each payment of a cost applies to only one spell, ability, or effect. For example, a player can’t sacrifice just one creature to activate the activated abilities of two permanents that each require sacrificing a creature as a cost. Also, the resolution of a spell or ability doesn’t pay another spell or ability’s cost, even if part of its effect is doing the same thing the other cost asks for.

What 117.10 is saying is that if an ability requires a cost such as "Sacrifice an artifact" (Throne of Geth), then sacrificing an artifact as the result of the effect of another spell or ability (Storm Fleet Arsonist) doesn't pay for that cost.
Or similarly, if you have an ability that requires you to pay life to activate it, losing life from another ability doesn't count as paying that cost.
Note that 117.10 is under the section on "costs", so it is really talking about activated abilities, not triggered abilities. Activated abilities occur due to a player choosing to pay a cost to activate them. Triggered abilities happen whenever something happens.
This is the difference between "Sacrifice a creature: gain 1 life" and "Whenever you sacrifice a creature, gain 1 life". The latter will trigger as a result of another ability making you sacrifice a creature, but the former will not.
See this often-duplicated question for a similar common confusion.

That sounds to me more like a Spike or Johnny move then a Tim(my) XD

@Andrew Tim is a nickname It is a reference to Monty Python, and the nickname predates Maro's original psychographics article

Activated abilities have costs that need to be paid.
Triggered abilities have conditions that need to be met.
Here's all of 117.10 from the comprehensive rules:

117.10 Each payment of a cost applies to only one spell, ability, or effect. For example, a player can’t sacrifice just one creature to activate the activated abilities of two permanents that each require sacrificing a creature as a cost. Also, the resolution of a spell or ability doesn’t pay another spell or ability’s cost, even if part of its effect is doing the same thing the other cost asks for.

The resolution of another ability can be the triggering condition of a triggered ability, like say Day of Judgment's resolution destroying all creatures to trigger Deathgreeter, all those creatures die so you gain one life for each.
Where the issue is say you play Storm Fleet Arsonist after combat and your opponent has Mogg Fanatic. Your opponent needs to sacrifice something because of your Arsonist's raid ability, they can't sacrifice Mogg Fanatic to your Arsonist's ability and use that sacrifice to deal damage with Fanatic's own ability. If they use Fanatic to deal damage, they still need to sacrifice something else for Arsonist, if they sacrifice Fanatic for Arsonist, they can't use it's ability to deal damage.
One thing to keep in mind, if a spell or ability creates mana or tokens, those can be used to pay costs, but they become their own objects, mana in your mana pool, tokens on your battlefield, and it's not the resolution of the effect you are using to pay, just what that resolution created.


text:
Can Recycle be sacrificed?
Can you sacrifice Recycle to draw cards again if another player has destroyed all lands?

Recycle tells you to skip your draw phase. When you play a card you can draw a card. Not having lands to be able to play spells suspends the deck from being able to be used. One of the rules of sacrifices is that it can be done if an effect is suspends play.

Re "if an effect is suspends play.", What?

Why would "if another player has destroyed all lands" have any bearing on sacrificing Recycle; or were you just intending to give a reason why you might want to?

@GendoIkari They can't make mana, so they can't play spells, so they can't draw cards.

@Andrew I understand that, but the wording of the question (using "if") seemed to suggest that the user thought the rule would be different under that circumstance.

No. You can't take an action you weren't instructed to take, so you can't sacrifice an object unless you are instructed to sacrifice it (as a cost, or as an effect).
Whether someone has destroyed all lands or not is irrelevant.

By the way, contrary to what you implied, Recycle doesn't prevent cards from being drawn.


text:
Can a creature with deathtouch be killed by a creature that it is killing?
If I attack with a Gifted Aetherborn (2/3 deathtouch and lifelink) and my opponent blocks with a creature that's a 3/3 (no abilities), does my Gifted Aetherborn die?
Without deathtouch it would, but since the Gifted Aetherborn only needs to deal 1 damage to kill the other creature, he should live, correct?

Both creatures receive lethal damage and as a result die.
In the Comprehensive Rules it says the following regarding deathtouch:

702.2b A creature with toughness greater than 0 that’s been dealt damage by a source with deathtouch since the last time state-based
  actions were checked is destroyed as a state-based action. See rule
  704.

So according to this rule any creature that get deathtouch damage gets destroyed.
But who gets to deal damage first? Is the the deathtouch creature? Is it because he only has to do one damage to do lethal damage? Let's find out in the next paragraph!

510.2. Second, all combat damage that’s been assigned is dealt simultaneously. This turn-based action doesn’t use the stack. No
  player has the chance to cast spells or activate abilities between the
  time combat damage is assigned and the time it’s dealt

So the 2 damage from Gifted Atherborn and the 3 damage from a 3/3 creature is dealt simultaneously resulting in them both perishing.
If you want to destroy the enemy creature with combat damage before it kills your creature you should take a look at first strike and double strike.

510.4. If at least one attacking or blocking creature has first strike (see rule 702.7) or double strike (see rule 702.4) as the combat
  damage step begins, the only creatures that assign combat damage in
  that step are those with first strike or double strike. After that
  step, instead of proceeding to the end of combat step, the phase gets
  a second combat damage step. The only creatures that assign combat
  damage in that step are the remaining attackers and blockers that had
  neither first strike nor double strike as the first combat damage step
  began, as well as the remaining attackers and blockers that currently
  have double strike. After that step, the phase proceeds to the end of
  combat step.

Both creatures die, including your Aetherborn.
Damage is dealt simultaneously and in full in the combat damage step. Then, once combat damage has been exchanged, we check which creatures have lethal damage marked on them. In this case both die: your 2/3 Aetherborn has 3 damage marked on it, which is lethal damage, and the 3/3 has damage marked on it from a source with deathtouch.
There isn't a "point race" or anything — your Aetherborn doesn't get to survive on account of needing to deal less damage to kill the other one. We don't zoom into combat in that much detail. If there was such a point race, nothing would ever kill a deathtouch creature with more than 1 toughness, since it would always outlive the other creature. Thankfully deathtouch isn't quite that powerful.
Your Aetherborn would survive if it had first strike or double strike and the 3/3 had neither, because it would deal lethal damage to the 3/3 during the first strike combat damage round, killing it before the 3/3 had a chance to deal damage back. This makes first strike & deathtouch (such as on Ankle Shanker) a pretty hard combination to deal with.
You can see the steps of the combat phase outlined in the very last page of the Basic Rules (pdf), or read further guidance about them (and the full comprehensive rules) on the MTG Wiki page for the Combat Phase and the  pages for each step which it links to.

The fact that your Gifted Aetherborn only has to deal 1 point of damage to kill doesn't matter for him living or dying from combat, what matters is how much damage he takes, and without First Strike or Double Strike involved, all damage is dealt at once.
For sake of argument lets say your opponent has a Hill Giant, that's the most common card used as an example of a 3/3 with no abilities.
The combat would work like this:
Even though Gifted Aetherborn only needs to deal 1 damage to the Hill Giant to kill it, the Aetherborn still needs to assign all its damage, so it assigns 2 damage to the Giant. (If it had trample, one damage could be assigned to the giant and one to the player.) The blocking Giant then needs to also assign all its damage to the attacking creature(s) it blocked, so it assigns 3 damage to the Atherborn. Then after this assignment all damage is dealt at once, 2 damage is dealt to the Giant, which is more than the 1 needed to kill it and 3 damage is dealt to the Atherborn, which is enough to kill it. Both of these creatures then die due to damage.
If either creature (but not both!) had First Strike or Double Strike, they would hit before the other creature, say if your Atherborn had been enchanted with Siege Modification, then it would be a 5/3 with First Strike, Deathtouch, and Lifelink. It would assign and deal all 5 damage to the Hill Giant before the Giant had a change to hit back, killing the giant, there would be no hit on the Atherborn, what would have hit it is dead already.
This is why first strike and deathtouch together are a very powerful combo, as is deathtouch and trample, one kills without getting killed, the other kills and keeps going to hit the player with whatever is left over damage wise!


text:
Progenitor Mimic copying a creature with counters
When Progenitor Mimic creates a copy of a creature like Nimbus Swimmer,  will Progenitor Mimic copy the counter that creature has on it?

No, counters are not copied. The Progenitor Mimic, when copying a Nimbus Swimmer, would enter the battlefield as a 0/0 creature and immediately go to the graveyard.
The Progenitor Mimic copies the Nimbus Swimmer's ability. However, X is zero everywhere except on the stack, so it will enter without +1/+1 counters and go to the graveyard the next time a player would gain priority.

107.3f If a card in any zone other than the stack has an {X} in its mana cost, the value of {X} is treated as 0, even if the value of X is defined somewhere within its text.

The spirit of 107.3f is mirrored in the rules for copying objects. The value of X can be copied, but only when it's on a spell or ability on the stack.

706.2. When copying an object, the copy acquires the copiable values of the original object's characteristics and, for an object on the stack, choices made when casting or activating it (mode, targets, the value of X, whether it was kicked, how it will affect multiple targets, and so on). The "copiable values" are the values derived from the text printed on the object (that text being name, mana cost, color indicator, card type, subtype, supertype, rules text, power, toughness, and/or loyalty), as modified by other copy effects, by its face-down status, and by "as . . . enters the battlefield" and "as . . . is turned face up" abilities that set power and toughness (and may also set additional characteristics). Other effects (including type-changing and text-changing effects), status, and counters are not copied.

As a matter of fact, the original progenitor mimic will die on entry too and never survive to make copies.

The easy way to understand copy abilities that a friend of mine explained to me once is to use the "Xerox rule".  The Xerox rule can be simply stated as: If you took the card (the physical card, the piece of cardboard) and put it through a Xerox machine (or your favourite photocopier brand I don't judge), what would come out the other side?  That's what you get when you use a copy effect.
In your specific case, the counters on the creature are not part of the physical card, and thus when you put the physical card through the Xerox, you wouldn't get counters out the other side.  Therefore, no, you don't get the counters.
Note that the Xerox rule is transitive.  That is to say, if you control creature A, and then cast spell B which copies creature A, then B will become (as per its card text; e.g. for Clone, it will become..., or for for Cackling Counterpart it will create a token which is...) a Xerox-copy of A (as defined above).  Then if you cast spell C which copies B, then C will be a Xerox copy of A (and not a Xerox-copy of B).
There are a couple small exceptions to this rule which fall very far outside the realm of the question you are asking so I'm not going to go super deep into those here, but this should be enough to get you started with this and similar situations.

That's not a very good rule of thumb though. If the creature you copy has itself copied another creature, that copy effect will also be copied. Example: Clone is a blue 0/0 creature. It copies a red 1/1 goblin. Another Clone enters and copies the first Clone. The second Clone will also be a red 1/1 goblin, not a blue 0/0.

My apologies, I forgot to mention that this rule is transitive.  Updating the answer now.

C doesn't become a copy of A, it becomes a copy of B with its copying effects in effect. For instance, suppose you have Hill Giant and Artisan of Forms in play. You cast a spell that targets Artisan of Forms, and you choose to have Artisan of Forms become a copy of Hill Giant. Then you cast Clone copying Artisan of Forms. Clone is now a Hill Giant with Artisan of Form's ability.


text:
What are you allowed to do if you only have 1 card in hand, and no Canastas yet?
In a four player game, if a player has only one card left but his team does not have a canasta, can he pull a card from the stack and discard one, still leaving him a card in his hand?
If the card he pulls is playable may he play it and pull another card until he has a discard that he could not play?

If the player cannot pick up the discard pile because he cannot meld the card on top, or it is frozen, then he has to pick up the top card of the draw stack, and just discard 1. He has no other choice.
He cannot play a card from his hand, unless playing that card would turn a 6-card meld into a 7-card Canasta, because he is not allowed to go out without a Canasta.
There is no rule that would allow him to play a card, and then draw another card. You only draw once per turn.


text:
Does a vehicle require a crew if it is enchanted to become a creature?
So, say I have a Consulate Dreadnought and I enchant it with Siege Modification. The Crew effect makes it to become an artifact creature, but if it is already an artifact creature, does it need to be crewed to attack?

No it does not. Siege Modification says that it's a creature in addition to its other types, so it counts as a creature for anything that cares about it being a creature, including the ability to attack with it.
This is the main point of Siege Modification's ability.

Thank you very much! I was pretty sure, but I wanted to get a second opinion before I made a fool of myself.

Another way to look at it: Siege Modifications makes the permanent a creature in addition to its other types. Crew also makes a Vehicle a creature in addition to its other types. If you have either one, the other doesn't do anything.

Though, You can still crew it.


text:
Canceling a creature spell during combat
Ok, so I play Shaman of the Pack (I'm using an elf deck) whilst having a few elves (6 or so), and my opponent takes the damage. His creatures are tapped out, and I have a 5/4 elf with an artifact equipped that gives +1/+1 for each creature that shares a type with it, and I begin to declare attackers. At this time, he decides to counter Shaman of the Pack. Is this a legal move or is he in the wrong?

As a technical thing that can matter sometimes.... your opponent doesn't "take damage" when Shaman enters the battlefield. He loses life, which is a different thing. Usually, taking damage will result in losing life, but they aren't the same thing.

In reference to GendoIkari's comment, See Deflecting Palm

If he has said that he takes the life loss from Shaman of the Pack then the spell has already resolved, entered the battlefield, the enter-the-battlefield-trigger has been put on the stack and resolved. It is then way too late to decide to counter the Shaman.
If he had not yet acknowledged the life loss from the Shaman verbally or by obvious gesture, then he still retains priority and you cannot decide to move to combat.
The important thing is that he acknowledged the loss of life.

Indeed the biggest problem in Magic is the steps and priorities. Verbally skipping priority is a drag, and in casual games, never used to expedite the matches. But the steps are still there - and if a player wants to do something in his priority, you have to give him a chance obviously. In tournament setting, you'd best ask if he had skipped his priority before such moves where you might be giving too much info. Play spell, and ask "do you pass priority?".

It is too late for your opponent to counter Shaman.
You mentioned that your opponent took the damage from Shaman's "enters the battlefield" triggered ability. Your opponent cannot take damage from an "enters the battlefield" trigger and then decide to back the game up to counter the creature that entered.

In this case though, the OP said that his opponent "takes the damage". If his opponent reduced his own life as a result of the ETB trigger, then that would be passing priority wouldn't it?

@GendoIkari Yea, you're right. I missed that part in the question. Thanks for pointing it out.

The actual confusion seems to be about what can actually be countered, which the rules clear up in an unusually short manner:

701.5a. To counter a spell or ability means to cancel it, removing it from the stack. It doesn’t resolve and none of its effects occur. A countered spell is put into its owner’s graveyard.

This requires the spell to be actually on the stack in the first place, as indicated by Counterspells targetting spells. Once a creature spell resolves and as a result enters the battlefield, it can't be countered anymore or targeted at all by Counterspells.
Your opponent seems to be under the impression that a counterspell is about the same as a destruction spell such as Murder, which is not the case.
As mentioned in the other answers as well, the fact that your opponent acknowledged the life loss from an ETB ability means they agreed to advance the game to a point where that creature had already left the stack and entered the battlefield, making this situation particularily easy to resolve - your opponent is not able to counter your creature at this point anymore.


text:
Is Metallic Mimic the chosen creature type when it enters the battlefield?
If I have Thalia's Lieutenant in play and resolve a Metallic Mimic choosing "Human" does Thalia's Lieutenant get a +1/+1 counter?

Yes
Metallic Mimic

As Metallic Mimic enters the battlefield, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.

When you are asked to do something "As X enters the battlefield", you are doing it immediately before it enters. This does not use the stack; when Metallic Mimic resolves you choose a type and it enters as that type, triggering any appropriate ETBs, and no one can do anything in between you choosing the type and Mimic hitting the battlefield.
If it instead read:

When Metallic Mimic enters the battlefield, choose a creature type.

Then it would be a triggered ability; Metallic Mimic would enter the battlefield as a "Shapeshifter", this ability would be put on the stack, and when it resolved you'd get to choose a type (like "Human") and it would become that type. Thalia's Lieutenant's ability would not be triggered.

Interesting, never really appreciated the difference between "When X enters the battlefield..." and "As X enters the battlefield...". Nice addition to the answer.

@Matt Thanks! Whenever an MTG question asks "does X happen", and X doesn't happen, I try to include counterexample Y, where it WILL happen, because I find those super helpful.


text:
Nissa - Vital Force, does the land that becomes a creature can get destroyed?
I want to ask about the +1 ability of Nissa, Vital Force.
If the creature (that was the untapped land) dies from combat damage or any other effects, is the land removed from battlefield afterwards? Usually I´d say yes, but the card explicitly says It´s still a land.
If it is removed, then can I bring the land back with the -3 ability?
Thank you.

You can also destroy lands that aren't creatures.

Yes, it will be destroyed by having sufficient damage on it. Also, Terror ('Destroy target creature.') will work just fine.
The text:

'It is still a land'

signifies that it can still tap for mana and that it is affected by spells and abilities that target lands (ie: 'Destroy target land').
Once it is removed from the battlefield, the card becomes just a land card. Since lands are permanents, you can target them with Nissa's -3 ability.

Dammit then my opponent was right. Guess I have to apologize to him. Thank you.


text:
Order of resolution on same player controlled cards
I have a Cathars' Crusade in play. I then play Zealous Conscripts. If my opponent's permanent I gain control of is a creature, does this creature also receive the counter from Cathar's Crusade?

You have the opportunity to choose whether or not that creature gets a +1/+1 counter. It comes down to how you order these two triggered abilities involved.
We'll examine giving it the +1/+1 counter first, then examine what you can do differently to makes sure it doesn't receive a counter.
To be clear for those readers who may not be certain: when you take control of your opponent's creature, it will not count as (re-)entering the battlefield, and so does not trigger Cathar's Crusade itself.
Making sure it receives the counter

You cast Zealous Conscripts.

You and your opponent pass priority (in theory), and then Zealous Conscripts resolves and enters the battlefield.

Because someone now receives priority, we check for any triggered abilities that now have to go onto the stack. Zealous Conscripts entering the battlefield has caused two abilities to trigger: that of Cathar's Crusade, and that of Zealous Conscripts. Because they triggered simultaneously, you may put them in whatever order you like:

603.3b If multiple abilities have triggered since the last time a player received priority, each player, in APNAP order,[note below] puts triggered abilities he or she controls on the stack in any order he or she chooses.

You choose to place Cathar's Crusade's ability beneath, and Zealous Conscripts' ability on top (the top one resolves first).

You resolve Zealous Conscripts' ability. Your opponent's creature comes under your control.

Cathar's Crusade's ability resolves and places a +1/+1 counter on each creature you control, including the one you took from your opponent.

If the creature survives to be returned to its owner, it will return with its +1/+1 counter still on it. How nice of you! (This could be a totally appropriate gift to an ally in a multiplayer free-for-all game.)
Making sure it doesn't receive the counter
At step 4 above, we'll make a different choice.

You choose to place Zealous Conscript's ability on the bottom, and Cathar's Crusade's ability on the top of it.
Cathar's Crusade's ability resolves first. It grants a +1/+1 counter to each creature you control, which at this point is just Zealous Conscripts and whatever else you already had.
Zealous Conscript's ability resolves, and you take control of your opponent's creature. It gets no counter.

Note: "APNAP" stands for "active player, nonactive player(s)". APNAP order means the active player does their thing, then each nonactive player in turn order. (In a 1v1, that just means one opponent is the NAP.) The active player is whoever is currently having their turn.


text:
Can the Bishop select a player who discarded the Handmaid?
In the premium edition of Love Letter, the player with the Bishop gets a heart if they correctly guess the card another player is holding. This doesn't directly affect the player being guessed upon, other than that they may discard their card, and that others get some information about that player's hand if they decide to keep it.
Can the player holding the bishop guess the hand of a player who is protected by the handmaid?

Edited title so that the answer isn't reversed from the question you ask at the end of your post.

Discarded in the title is technically correct, but can be vague - you could discard the handmaid due to a Prince forcing you to discard it, but you wouldn't benefit from her protection. Is there a better way to phrase this?

No, the Bishop cannot guess the hand of a player who discarded the Handmaiden last turn.
This comes from the original rules:

If all players other than the player whose turn it is are protected by Susannah, the player must choose him- or herself if possible.

This shows that the Handmaid doesn't only cause the player to not be affected, but it actually stops another player from choosing that player when choosing a player.
Also, having to reveal whether or not you hold a specific card is definitely being affected. If you are ignoring all effects from other players cards, then you would ignore the part where you must answer whether or not you have the guessed card.


text:
Love letter: If you discard a constable and lose, do you get an affection token?
In the rules, if you are eliminated with the constable in your discard pile, you gain an affection token.
If I discard the constable, and then lose on points at the end of the round, have I been eliminated and thus get an affection token? Or did I just lose, and not get an affection token?

You must be eliminated before the end of the round.
Text from Constable:

If this card is in your discard pile when you are knocked out of the round, gain an Affection Token.

(Emphasis mine)
In the rulebook for the original Love Letter, the phrase "knocked out of the round" is used several times, and in each case it is only referring to being eliminated while the round is still going. Example:

If you discard the Princess—no
  matter how or why—she has tossed
  16
  your letter into the fire. You are
  knocked out of the round.

(Emphasis mine)
Under the rules for "End of a round", no mention is made of being knocked out:

The player with the
  highest ranked person wins the
  round.

So being "knocked out of a round" is something that specifically happens from the effects of a card that was discarded.

OK - so for clarification, you can

Win a round by being the survivor with the highest points
Lose the round by surviving but not having the highest points
Get knocked out of the round by some action, like discarding the princess or being attacked by a guard

Only in the 3rd case do you get an affection token by using the constable, so try hard to get knocked out once you've discarded him!

Yes, that's correct.


text:
Does drawing a card still end your movement after the haunt has begun?
After the haunt does your turn still end in a newly discovered room that has an event or omen? If so this seems to make it very difficult to get away from monsters.

Yes, your movement will always end after you enter a newly discovered room with a symbol in it. This does mean you can have some claustrophobic haunts, but it is the way the game is played.

It is more accurate to say that your movement will end. You can still take actions in the newly discovered room.

Yup, you're right. Edited.

Actually, your movement will end if you draw a card for any reason, whether it was for revealing a new icon-bedecked room or for some other reason (such as opening the Puzzlebox).
From the rulebook (italics mine):

Move
On your turn, you can move up to a number of spaces equal to your character's current Speed.  You can perform actions (such as
using an item or attacking) in the middle of your movement.  However,
whenever a game effect makes you draw a card for any reason, you
must stop moving for the rest of the turn.

This rule does not change once the haunt has been revealed.


text:
Recurring nightmare-Pia's Revolution
If I have a Recurring nightmare and a Pia's Revolution in play, can I sacrifice an artifact creature and then return it to my hand along with the Recurring Nightmare and an additional creature card from my graveyard?

It would be helpful if you edit your question to include some detail about what part of the interaction you are unclear about. Is there a reason you think that it might not work like you suggest?

That's more or less right, though things happen in a specific order.
First you activate the ability on Recurring Nightmare. To do this, must choose the target creature that you wish to return to the battlefield. Note that the artifact creature you plan to sacrifice is not in the graveyard at this time, so it is not a legal target.
You pay the cost of sacrificing a creature (choosing an artifact creature) and returning Recurring Nightmare to your hand. This places the ability on the stack.
Then the triggered ability on Pia's Revolution triggers because a non-token artifact was put into your graveyard from the battlefield. At this time you must choose a target opponent, and then the Pia's Revolution's ability goes on the stack.
Assuming both players choose to pass priority now, the Pia's Revolution ability will resolve. The target opponent chooses whether to take 3 damage or allow you to return your artifact creature to your hand. Whichever they choose will happen.
Then, assuming both players choose to pass priority again, the Recurring Nightmare's ability will resolve, which will allow you to return a creature card from your graveyard to the battlefield.
The end result will be 1 of 2 things, depending on your opponent's choice:

You have Recurring Nightmare in your hand, the artifact creature you chose to sacrifice in your hand, and another creature that was in your graveyard is now on the battlefield.
You have Recurring Nightmare in your hand, and another creature that was in your graveyard is now on the battlefield. The artifact creature you chose to sacrifice is still in the graveyard, but your opponent takes 3 damage.

I was confused because I wasn't sure if I was using multiple effects when sacrificing the artifact creature.  I'm glad you cleared that up for me. Thanks!


text:
Removing creatures from my library in game
Looking for a way to utilise Mortal Combat as a win strategy and was wondering if there are any way to get my creatures into my graveyard without self mill. Let me know if you have any suggestions.

Don't you by definition want self-mill? You're trying to move cards from your library to your graveyard, and that's what self-mill is. I guess maybe you're hoping for something that specifically pulls out lots of creatures and leaves the rest alone?

Iname, Death Aspect.  Sadly, I can't take credit for this.  Saffron Olive figured that out.


text:
What happens if I sacrifice the land chosen by Glacial Chasm?
When Glacial Chasm enters the battlefield, you have to sacrifice a land. Is it possible to sacrifice, let's say a fetch land, after the glacial chasm targets it for the enter the battlefield trigger?
I was sure the land you were supposed to sacrifice to glacial chasm trigger had to be sacrificed by glacial chasm, and could not be sacrificed in response. Would not the target of glacial chasm now be illegal?

Possible duplicate of Can I pay two different costs with the same payment?

Actually I don't think this one is a duplicate of that, because the asker's confusion seems to come from when the land for Glacial Chasm's ability is chosen.

Definitely not a dup, because Glacial Chasm's effect is a trigger not a cost.

No.
The important thing here is that Glacial Chasm's enter the battlefield ability does not target. Just because a spell or ability has you chose something doesn't mean that the spell or ability targets that thing.

114.1a An instant or sorcery spell is targeted if its spell ability identifies something it will affect by using the phrase “target [something],” where the “something” is a phrase that describes an object, player, or zone. The target(s) are chosen as the spell is cast; see rule 601.2c.

If a spell targets, it will have the word "target" in the rules text. The exceptions being that aura spells are always targeted, and some keyword abilities, such as equip, have the word target in the rules of the keyword rather than printed on the card.
So in this case, because the ability does not target, you do not choose the land you will sacrifice until the ability resolves. So if you sacrificed a fetch land in response to Glacial Chasm's enter the battlefield trigger, you will still have to chose a land to sacrifice when that trigger resolves, and by that time your fetch land will no longer be available to choose.
If the ability said "sacrifice target land" instead of "sacrifice a land", then you could do what you want, because targets are chosen when the ability is placed on the stack, not when it resolves. However, the phrase "sacrifice target ____" does not appear on any MTG cards currently. It would be a strange thing to have, because "sacrifice" already requires you to choose a permanent you control.

There are a few cards where a target is sacrificed, but they distinctly use the word target.

@KamilDrakari Interesting! I had searched for "sacrifice target" which doesn't exist on any cards. The difference of course being that with the cards you found, you can cause an opponent's creature to be sacrificed.


text:
Token copies with Scarab God
If I control The Scarab God and I activate his second ability and target Consuming Aberration is the token copy a 4/4 or is it still equal to the number of cards in my opponents' graveyard?

It is a 4/4.
Because The Scarab God's copy ability sets the power and toughness, the characteristic defining ability of Consuming Aberration is not copied.

706.9d When applying a copy effect that doesn’t copy a certain characteristic, retains an original value for a certain characteristic, or modifies the final value of a certain characteristic, any characteristic-defining ability (see rule 604.3) of the object being copied that defines that characteristic is not copied. If that characteristic is color, any color indicator (see rule 204) of that object is also not copied.

Example: Quicksilver Gargantuan is a creature that reads, “You may have Quicksilver Gargantuan enter the battlefield as a copy of any creature on the battlefield, except it’s still 7/7.” Quicksilver Gargantuan enters the battlefield as a copy of Tarmogoyf, which has a characteristic-defining ability that defines its power and toughness. Quicksilver Gargantuan does not have that ability. It will be 7/7.

And we wonder why so many law students play Magic...


text:
Targeting the same spell on stack
If I play Grapeshot and my oponnent plays Negate, can I play a Remand on Grapeshot to send it back to my hand?

What makes you think there might be a problem with doing this?

This is Grapeshot - you might want to remand it ANYWAY just so you can play it again, since your storm count is now going to be 2 more than it was before!

@corsiKa Three, even, thanks to the enemy counterspell counting as well.

Yes, this is fine.
Remand will counter Grapshot and move it to its owner's hand. Then, when it comes time for Negate to resolve, it will be countered by the rules instead (for not having any legal targets).
It's worth noting that Negate is particularly ineffective against Grapeshot as it will not stop the copies from being made even if it counters the original spell.


text:
Cards that double mana
I am looking for a card that doubles my mana.
I have found Doubling Cube, but I'm not sure if it is good or not? If anyone know something better please let me know. I have a Blue Red Black Commander deck.

There is only one card that doubles all kinds of mana, and that is Doubling Cube.
There are also some cards that generate mana when certain kinds of sources generate mana, which effectively doubles mana from those sources. This Scryfall search shows several cards that do that in your colors (plus a couple of false positives). Some of those cards that are popular in Commander are

Crypt Ghast
Extraplanar Lens
Gauntlet of Power

Another card with similar functionality is Liliana of the Dark Realms, a planeswalker with this ultimate ability:

−6: You get an emblem with "Swamps you control have '{T}: Add {B}{B}{B}{B} to your mana pool.'"

As you can probably see from the previous answer, With your colours there aren't many effective methods of doubling mana... However Rakdos (Red/Black) has good cards that can reduce costs or generate manna when certain criteria are met. The most worthy mentions I've ran into are:
Rakdos, Lord of Riots
Neheb, The Eternal
This search result shows many Red, Blue and Black "Mana Dorks" for increasing mana.


text:
How does manifesting work?
If I play Soul Summons, and manifest a card from the top of my library,
1) Do I get to see the front of the card?
2) Does my opponent get to see the front of the card?
3) If I am not allowed to see the front of the card, how will I know if it is a creature or not?
4) Does a manifested card go onto the stack before it goes onto the battlefield?
5) Is the card manifested at the time that my manifesting spell resolves?

Yes, you may look at the card, since you control it:

707.5. At any time, you may look at a face-down spell you control on the stack or a face-down permanent you control (even if it’s phased out). You can’t look at face-down cards in any other zone or face-down spells or permanents controlled by another player.

No, your opponent may not look at the card, since 707.5 only allows the controller to look at it.

N/A see #1

No, a manifested card does not go on the stack; manifesting is an action taken as part of a spell/ability resolving.

See #4

Also, see rule 701.34 for more information on the keyword Manifest.

For #4, I think they are asking the OP if "Turn it face up any time for its mana cost if it's a creature card." uses the stack. The answer is no. It's a special action that can be performed whenever you have priority. [CR 701.32b]

@ikegami I think that would probably be a good thing to include in an answer.

@ikegami they specifically mentioned "goes on the battlefield" so that doesn't sound like flipping.

Jon's answers for 1-3 are correct but there's some ambiguity in the question (and thus the answers) for 4 and 5 wasn't really addressed.

The front face of a morphed or manifested card is known to the controller of that card, in order to know you can look at it at any time. (707.5)
No, your opponent does not get to see the front face of any cards placed face down, unless they have some effect allowing them to (Lens of Clarity). They do get to know which face down creature is which however. (707.6)
Since you are always allowed to look, you will always know.
This question could mean a few things, but for manifest the answer is always no (this is different for morph):

If you are asking if the card goes on stack when it moves from the top of the library, no. The ability that caused it to move was on stack, but the manifested creature was not. (note: this is not true for morph, which is casting that card face down, this uses the stack)
If you are asking if the card goes on stack when it is turned face up, no. The creature never leaves the battlefield, paying to turn it face up does not use the stack either. (note: this one is true for morph also)

Yes. Spells and abilities that manifest a creature work like every other spell or ability, the instructions on them are followed while it is resolving and when it finishes resolving and is removed from the stack, their effects will have happened. In the case of manifest, when the spell or ability that causes a creature to manifest will have caused it to manifest before it finishes resolving.


text:
Victimize with Noxious Ghoul and opponent's Murder
I play Victimize targeting some creature I have. Victimize resolves and returns Noxious Ghoul and some other creature with an ETB triggered ability to the battlefield at the same time. Both my creatures triggered abilities trigger and I choose to let Noxious Ghoul's triggered ability trigger first. In response to the first triggered ability, my opponent chooses to Murder my Noxious Ghoul. Noxious Ghoul's triggered ability will still be on the stack, but will my other creature trigger Noxious Ghoul's triggered ability giving non-zombie creatures -2/-2 instead of -1/-1?

Note that Victimize targets two creatures in your graveyard, where the creature you choose to sacrifice isn't targetted.

Creatures entering the battlefield at the same time cause each other's abilities to trigger. Triggering Noxious Ghoul's ability requires either itself or another card of the Zombie creaure type to enter the battlefield - if the other creature isn't a Zombie, only Noxious Ghoul will trigger it's own ability.
That said, assuming the other creature is a Zombie, both abilities trigger at the same time, along with any other ETB abilities that might trigger. Then, those abilities are put on the stack in APNAP (active player, non-active player) order, and for each player in the order of their choosing. Only at that time can players cast spells or activate abilities.
Abilities on the stack exist independent from their sources. If Noxious Ghoul's ability triggered twice, destroying a creature on the battlefield won't remove the ability from the stack. Unless it's countered by something like Stifle, both abilities will resolve, giving non-Zombie creatures a total of -2/-2 until end of turn.


text:
Ambuscade Shaman + Warstorm Surge
Say you have Ambuscade Shaman and Warstorm Surge out on the battlefield and you cast a 1/1 creature. Does it deal 1 damage or 3?

1 damage or 3, it's up to you
Both Ambuscade Shaman and Warstorm Surge trigger at the same time, when your 1/1 creature enters the battlefield. Since you control both, you get to decide what order they're put on the stack.
If you put Ambuscade Shaman's trigger on the stack first, then Warstorm Surge's trigger on top, then the damage trigger will resolve first and deal 1 damage to target creature or player. Then, Shaman's trigger will resolve giving the creature +2/+2 until end of turn.
If you put Warstorm Surge's trigger down first, then Shaman's trigger will resolve first, giving the creature +2/+2 until end of turn, and then Surge's trigger will resolve, dealing 3 damage to target creature in player.
Suffice to say, it's likely that you want the second scenario to occur most of the time.


text:
Goryo's Vengeance and Veil of Secrecy
Can I cast Goryo's Vengeance and use Veil of Secrecy's arcane ability, to target the creature I returned with Goryo's Vengeance?
If this is possible, at what point has my opponent priority or what can he counter?

No, you can not
From the Comprehensive Rules (Ixalan (September 29, 2017))
Splice is a static ability that functions while a card is in your hand.
“Splice onto [subtype] [cost]” means “You may reveal this card from your hand as you cast a [subtype] spell. If you do, copy this card’s text box onto that spell and pay [cost] as an additional cost to cast that spell.” Paying a card’s splice cost follows the rules for paying additional costs in rules 601.2b and 601.2c

Seeing as the card is still in the graveyard, it's not a legal target for the Veil, and all spells you cast needs all its costs paid and legal targets (If it does indeed target anything.) before you can cast it.
source


text:
Magic: The Gathering - Does Captivating Crew's ability resolve if I bounce it in response?
My opponent has Captivating Crew in play.
They activate the ability to take control of one of my creatures.
In response I play Perilous Voyage and bounce the Captivating Crew back to their hand.
Do they still gain control of my creature?

Yes, they still gain control of your creature.

112.7a Once activated or triggered, an ability exists on the stack independently of its source. Destruction or removal of the source after that time won't affect the ability.

This is the same for any sort of ability; removing the source does nothing to the ability itself.

Caveat: In a multiplayer game, if the player who owns the ability loses while it's on the stack, the ability goes away. So in that sense it doesn't exist entirely independently of its source.

@Arthur, You merely demonstrated it doesn't exist independently of its owner. As the rules say, it exists independently of its source.


text:
If Mirage Mirror becomes a copy of a creature, and then is put into the library some how, does it still stay a creature until end of turn?
If I turn Mirage Mirror into a copy of a creature, and then put it back in the library, is it still a creature until end of turn, or does it go back to being an artifact in the library?

No, it's just an ordinary Mirage Mirror artifact once it's in your library. It won't still be a copy of anything.
The key rule here is:

400.7. An object that moves from one zone to another becomes a new object with no memory of, or relation to, its previous existence. There are nine exceptions to this rule:
(None of the exceptions apply. They're mostly about cards keeping track of each other between zones when they need to.)

Generally after something moves to a new zone, it's reset to a fresh state of just being whatever the card says.


text:
Magic the gathering, ixalan standard, bristling hydra
I have a Bristling Hydra on the battlefield, which states I can pay 3 energy and give him a +1/+1 counter and give him hexproof. My opponent has an Ahn-Crop Crasher, which states he may exert him and target creature can't block this turn.
My opponent exerts Ahn-crop crasher and targets my Bristling Hydra. In response, I pay 3 energy and give him hexproof. In response, my opponent played Lightning Strike, dealing 3 damage to my Hydra.
Wouldn't me activating the trigger ability of the Hydra on the Crasher still give him hexproof? I was told otherwise from the judge and my Hydra was destroyed. Was this a legal move?

The same thing that lets you pay the energy to give +1/+1 and hexproof lets
your opponent cast the lightning strike.

Your opponent can do this.
After he exerted Ahn-Crop Crasher, the triggered ability went on the stack. Then, you activated Bristling Hydra's activated ability in response, which went on the stack above the triggered ability. Then, your opponent cast Lightning Strike, which went on the stack above your activated ability.
At that point, the stack looks like this (from top to bottom):

Lightning Strike
Bristling Hydra's activated ability
Ahn-Crop Crasher's triggered ability

If no one else does anything, the stack will begin to resolve, starting from the top. So Lightning Strike will resolve. At this point, your Hydra's activated ability has not yet resolve, so the Hydra wouldn't have hexproof yet.


text:
Nekusar and the new damage redirection to planeswalkers
So to be clear, Nekusar, the Mindrazer only hits players with the newest rules change and no longer can hit Planeswalkers?

Correct.
Most cards that previously dealt damage to a player received errata to allow them to target a player or planeswalker, but as Nekusar’s ability is not targeted; the standard errata wouldn’t have made as much sense (mostly because you don’t choose or target a player).
You can see the current wording of any card in Gatherer; the wording there is what counts. And with the planeswalker damage redirection rule change; the question is simple for any card; because cards that can damage planeswalkers will specifically say so (or they will say "any target").

When in doubt, look at the text in Gatherer.  Gatherer lists the official, most up-to-date card text, so if a card can damage planeswalkers it will say so (or say "any target")


text:
Pokemon Asleep Status
I have looked all over for this and can't find any good information on the sleep status, even in the rule book.
This came up because in a game recently with a friend: I was put to sleep with an attack that had 100% chance to do so, after I had less cards in my deck, effectively causing me to lose.
As I currently understand it, flipping to remove the sleep status happens after my turn, so even if I remove it they can just apply it right away again.
Is this the correct way that sleep works? If so, how do I avoid automatically losing as soon as an opponent has a sleep attack?

From the rules, p15:

Between turns, flip a coin. If you flip heads, the Pokémon wakes up.

So you flip a coin to wake up your pokemon after every turn - both yours and your opponent's. This means that even if the opponent can put your active pokemon to sleep every turn and you have no other way of cancelling it (like evolving the pokemon, or sending it to the Bench with a Switch), there's still a half chance that by the time your turn starts it'll be awake and able to act.

ok so i think i was doing this wrong before. the game out be friend puts me to sleep it's my turn and i do my stuff. Then it's their turn again and now I flip to get my pokemon out of sleep condition?

Yeah, "retreat" is a special action you can take once per turn for free (see p12) but it's blocked by Asleep; "Switch" is a specific card that happens to cause an effect very similar to retreating, and it's not blocked by Asleep.

aa so to defend against sleep I need to build my deck better it would seem

From the rules, p15:

Between turns, flip a coin. If you flip heads, the Pokémon wakes up.

Between turns means, before and after your turn.  So your opponent does an attack that leaves you asleep, their turn is over, before you do anything flip a coin to see if you wake up between his turn and your turn.  if you perform an attack that puts your Pokemon asleep your turn is over, but you need to flip a coin to see if your Pokemon wakes up.
If your Pokemon is asleep during your turn, then you can use an item card that removes special conditions or use a Switch to change the active Pokemon, the one that goes to the bench has all conditions removed unless there is a card in play that prevents the loss of the special conditions when a Pokemon is moved to the bench.
Snorlax GX has an attack that can only be used if Snorlax is asleep, I believe there are other Pokemon that operate this same way as well. So you want to be asleep, but you still have to flip a coin after your turn where you put your Pokemon to sleep and before your turn where you use the attack that your Pokemon must be asleep for.


text:
Can Brago's ability keep Traft's angel token around?
If I attack with Brago, King Eternal and Geist of Saint Traft, can I have Brago's ability flicker the Traft angel token so that it won't be removed at end of combat?
Related:
Can I flicker Traft and Brago as well so that they are untapped?
Related:
If I have a Pentarch Ward on Traft, can I flicker both the ward (to get another card) and Traft (to make him untapped) without losing the Pentarch Ward?

If a token would leave the battlefield to any other zone it will cease to exist.

110.5g A token that has left the battlefield can’t move to another zone or come back onto the battlefield. If such a token would change zones, it remains in its current zone instead. It ceases to exist the next time state-based actions are checked; see rule 704.

You can flicker your traft and brago and yes since they are entering the battlefield they would be untapped and also have summoning sickness.
If you flicker a creature that's enchanted the enchantments would be removed and sent to the graveyard. Now if you flicker both the ward and the creature then I'm not sure but you might have to enchant another creature aside from the one re-entering since they enter at the same time and the enchantment wouldn't "see" the creature flickered along with it.

Do permanents flickered by Brago really return at the same time? I was thinking perhaps their return could be ordered like when multiple abilities trigger at the same time.

If they have ETB abilities you could stack those anyway you like. As for the cards being flickered they all leave simultaneously and return simultaneously.

The brago ability goes on the stack you chose the permanents you want to flicker and then it resolves by flickering the chosen nonland permanents all at once

Taken from Brago, King Eternal's oracle text:

If you exile an Aura with Brago’s last ability, the Aura’s owner chooses what it will enchant as it comes back onto the battlefield. An Aura put onto the battlefield this way doesn’t target anything (so it could be attached to a permanent with shroud, for example), but the Aura’s enchant ability restricts what it can be attached to. The Aura can’t enter the battlefield enchanting a permanent that enters the battlefield at the same time. If the Aura can’t legally be attached to anything, it remains exiled.

@Greg The objects enter the battlefield at the same time. However, you are correct in that each object gets a different timestamp when they enter, and if multiple objects enter at the same time, the active player determines their relative timestamps. See rule 613.6c + j. Timestamps are important to correctly apply continuous effects under certain conditions.


text:
Prismatic omen and gruul turf
If I have both Prismatic Omen and Gruul Turf on the battlefield, can I tap the Gruul Turf for two of any land type it's become now, or does it still only add one g and r?

Gruul Turf will have 6 separate activated abilities. One of them is to tap for RG, the others each tap for 1 mana, 1 ability for each color. So no, you cannot tap for 2 mana of any color.
Also a note on terminology, tapping a land adds a mana to your pool, it does not add a land or land type.


text:
Killing Avacyn Before She Transforms During Upkeep?
Long question short: Can I kill an un-transformed Archangel Avacyn during the upkeep she's due to flip, before she flips?
From how I understand it (copied by from a comment from murgatroid99):

A non-Angel creature dies. Archangel Avacyn's triggered ability goes on the stack.
Archangel Avacyn's triggered ability resolves, and creates a delayed      triggered ability.
At the beginning of the next upkeep, the delayed triggered ability goes on the stack.

Could I, for example, cast an instant like Lightning Axe at this point, and deal 5 damage to the currently 4/4 Avacyn? Thus preventing the transformation and the damage that is dealt on the flip?
Thanks for any help in advanced!

Yep, this works just like you think it does. Avacyn's delayed trigger goes on the stack, you have a chance to respond and kill her. If you do, she can't transform, so the triggered ability does nothing as it resolves.


text:
Does being targeted with Moonlight Hunt allow my creature to return damage?
Opponent targeted me with Moonlight Hunt; would my creature It That Rides as One return damage or do any fighting to any of the wolves or werewolves that were chosen to fight me ?

What do you mean by "return"? What "fighting" are you referring to?

Choose target creature you don't control. Each creature you control that's a Wolf or a Werewolf deals damage equal to its power to that creature.

Right. That's the text of Moonlight Hunt. It says that some creatures deal damage to a specific other creature, and that's it. It doesn't say anything about something "returning" or anything "fighting", so I'm not sure what you're referring to.

@murgatroid99 Pretty sure it's just some inexact language - the OP is saying "return" as in "deal damage in return", and they're saying "fight" to mean "deal damage to". Obviously that's not what the card says or what fight means, but... it's what the OPs asking about.

Right; that's how I figured after a few readings. dokepa, note that "fight" is a specific keyword in Magic; this card doesn't use that word so it doesn't cause creatures to fight.

No.
The only thing that Moonlight Hunt does is specifically what it says: each wolf or werewolf that your opponent controls will deal damage to your It That Rides as One. Your creature will not deal damage in return because the spell doesn't say it does.
Note that Moonlight Hunt does not cause creatures to fight each other. "Fight" is a keyword that causes creatures to deal damage to each other; which may be what you are thinking of. But Moonlight Hunt doesn't use the word "fight"; so it doesn't have anything to do with "fighting".


text:
Matsu-Tribe Decoy vs. Trap Runner
If I activate Matsu-Tribe Decoy's ability targeting opponent's Trap Runner, can he activate Trap Runner's ability, blocking my creature, and making Trap Runner an illegal target for Matsu-Tribe Decoy's ability?
https://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=75247
https://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=22288

No. For this particular combination of cards, there is no time during which the Matsu-Tribe Decoy is a legal target for Trap Runner's ability.
The Oracle text for Trap Runner's ability says:

Target unblocked attacking creature becomes blocked. Activate this ability only during combat after blockers are declared.

Since this ability can only be activated after blockers are declared, Trap Runner would first have to block the Decoy... but then the Decoy is no longer an unblocked attacking creature.

Note also that your question asks about making the Trap Runner an "illegal target" for the Decoy's ability. Nothing about the Decoy's target being tapped (or otherwise unable to block) would make it an illegal target... just not one worth spending the mana on.

Why can this ability only be used after blockers are declared?  Edit: NM, found the relevant rule; 509.1h governs when an attacker becomes a unblocked attacker, so before blockers are declared there is no legal targets.

While you are correct, and there is no such thing as an "unblocked" attacker before blockers have been declared, note also that Trap Runner explicitly specifies this window in its oracle text, so it would be true even if 509.1h didn't exist.


text:
"Target attacking creature gets -3/-0 until end of turn" Help a noob out!
So I understand the concept of dealing damage in the form of -X/-X to a creature.
The card in question is Elven Palisade.
But with the example in my title, what's the point? If I use this enchantment on my opponent to give a creature of his -3/-0 until end of turn, wouldn't that -3/-0 disappear at the end of my turn and then his creature would be back to normal again? If I was dealing damage and reduced his toughness to 0 or less then I'd understand the significance, it would kill the creature.
I know there are similar questions out there but they usually revolved around the toughness, not power. I'm also fully aware that my vocab here might make some of you cringe, but I'm just starting and trying to learn. Any help would be awesome! Thanks.

Note that because it says "target attacking creature"; you aren't even allowed to use it on your opponent's creature unless that creature is attacking, meaning it will be your opponent's turn.

The -3/-0 of Elven Palisade is the effect of its activated ability. It's not something that happens when you cast the palisade (which indeed will usually happen on your turn).
You can activate the ability (and pay the cost of sacrificing a forest) any time you have priority. But (as noted in the comments by Gendolkari) you must choose an attacking creature as the target, so generally you will do this during the opponent's turn after they declared attackers and make one of the attacking creatures less powerful until the end of their turn.

Let me help you with your vocabulary. I feel that, if you understand this terminology better, understanding of the rules will follow. Magic is very consistent in its wording, so it helps to understand that.

So I understand the concept of dealing damage in the form of -X/-X to
  a creature.

You do not 'deal damage' in the form of -X/-X. The term 'dealing damage' is reserved for combat (when a creature uses its power-stat) and for 'burn'-spells or abilities that explicitly say 'deal damage'. See, for example, Shock or Spikeshot Goblin.

The card in question is Elven Palisade. But with the example in
  my title, what's the point? If I use this enchantment on my opponent
  to give a creature of his -3/-0 until end of turn, wouldn't that -3/-0
  disappear at the end of my turn and then his creature would be back to
  normal again?

You are right that the effect is not permanent. A -3/-0 will normally not kill a creature, and the ability on Elven Palissade explicitly state that it ends at end of turn.
I notice that you speak of enchanting his creature, but that's not the case here. You have an enchantment in play that has an activated ability (and it's the ability that gives a -3/-0), like Compulsion. This is not an enchantment that is attached to a creature, like for instance Insolence is.
So, when to use this ability? Well, you can activate this ability on his turn. When he attacks with a Trained Armodon, you can sac a forest to give it -3/-0 and avoid getting damaged. If you also block it with, for example, a 4/2 Firewing Phoenix, the Phoenix would kill the Armodon, but stay unharmed himself.

If I was dealing damage and reduced his toughness to 0 or less then I'd understand the significance, it would kill the creature.

Damage does not reduce toughness. -X/-X reduces toughness. Damage stacks until it's equal or greater than a creature's toughness and the creature dies. If a creature is damaged in a turn, but not sufficiently to kill it, the damage wears off.
A special case is dealing too little damage to a creature to kill it, but using another effect to reduce its toughness.

For completeness, recommend referencing that it is a State Based effect that causes the creature to die.

Ok I'm definitely screenshotting these for reference. Thank you for helping me understand more than I was asking!

Giving a creature -X/-X is not dealing it damage. It simply reduces its power and toughness. A creature dies when it has damage marked on it greater than or equal to its toughness, or when it has zero toughness. So the toughness reduction makes it easier to kill or may just kill it outright, but it doesn't do so by dealing it damage.
So no, reducing a creature's power won't kill it. But that doesn't mean it's completely useless. The big reasons you might want to reduce an attacking creature's power:

you want to take less damage from an attack (effectively gaining life)
you want to block the attacking creature, and have your blocking creature less damage. For example, blocking a 5/3 with a 3/3 normally means they'd trade. But if you can turn your opponent's creature into a 2/3, your 3/3 will survive.

So you can cast Elven Palisade, and it'll sit around on the battlefield doing nothing until you decide you want to activate its ability. Since it has to target an attacking creature, you'll have to wait until your opponent attacks to use it. At that point, hopefully you'll be able to take advantage, using its ability on one or more attacking creatures of your choice. If you're really lucky, just the fact that you could use it will force them to be more cautious about attacking. But that also makes it much less likely you'll be able to take full advantage; they can just avoid dangerous attacks.
Obviously those things aren't as powerful as killing the creature outright, and sacrificing a land is a steep cost, so Elven Palisade isn't exactly the most powerful card. But the effect in general is far from useless.

So as an enchantment can't I only use it on my turn? This is how I'm interpreting the card(most definitely incorrectly). Reducing the opponents' creatures' power will only apply during my turn since the card says "until end of turn" and therefore when my turn ends and my opponents takes his turn he'll have his card back to normal. Or does this enchantment carry over from my turn to his turn?
Also, thanks for helping @Jefromi !!

An enchantment just sits on the battlefield.  In the case of Elven Palisade it has an activated ability that you can activate at any time.  You don't sacrifice a forest when you play the card, and it has no effect at that time.

First off, effects that reduce power and toughness are not damage, and damage does not (normally) reduce toughness.
You are correct that reducing the power of your opponent's creature won't kill it, and it'll be back to normal the next turn. What it does do is reduce the damage the attacking creature does. This can potentially buy you time to find a better answer, or prevent an ability that would trigger on combat damage. If it buys you one turn, but that one turn is enough to win, it's done work for you. Maybe there's some effect that cares about the creature's power; you might have a Puncturing Light that you want you use to actually destroy the attacker but the attacker is too big.

That's where I'm confused. "it'll be back to normal the next turn". Do you mean the opponent's next turn? Here's my response to the other person who answered:
So as an enchantment can't I only use it on my turn? This is how I'm interpreting the card(most definitely incorrectly). Reducing the opponents' creatures' power will only apply during my turn since the card says "until end of turn" and therefore when my turn ends and my opponents takes his turn he'll have his card back to normal. Or does this enchantment carry over from my turn to his turn?
thank you for your help @Michael !


text:
What happens if your only pawn can't move as many spaces as required?
If you have just started and you draw a move backwards 4 card, on your next turn you get a move forward 12. You have no other pawns out to move. Do you have to move The original pawn (the one you backed up 4) forward or can you refuse the move?

While you can move backwards from Start to just outside the safety zone, you can't move forward past the safety zone without going toward Home. Since a 12 is too much to land you in Home, and you can't move forward past Start, you must forfeit your turn.

Short answer: That man cannot be moved due to being too close to home and, if no other man can be moved, your turn is forfeit.
Unless the card text specifically states otherwise, you MUST perform the action indicated by the card if possible. You'll notice that all cards except 11 begin with the word MUST. The following cards have some implications with regards to this rule:

The 2 card's DRAW AGAIN happens regardless of if you could move any man.
The 7 card can only be used if you either one man that can move 7 or two men that can move a combined 7 spaces. If you have one man that's 2 spaces away from HOME and your only other man is 3 spaces away from HOME, your move is forfeit.
The 10 card must be used if you have any man not on the HOME or START spaces on the board. If no man can be moved 10 spaces forward, you are required to move one man back one space if possible.
The 11 card actually has a voluntary turn forfeit option as part of the alternate action. If none of your men can move 11 spaces forward and you do not want to exchange a margin man (a man not in your start or safety zone) with another player's margin man, you are not required to use the card.
The Sorry card is mandatory so long as any other player has a margin man and you have one man in start. Otherwise, you forfeit your turn automatically.

In the situation where your first four card draws were a 2, a 4, a 12, and a 10, the following would happen:

The 2 would start a man out and immediately give you another turn.
The 4 would move that man backwards 4 spaces, to the corner space.
Provided that man is still in the corner (the scenario outlined by Barb), the 12 WOULD BE FORFEIT because the man is 8 spaces away from HOME and no other man can move.
Provided the man is still in the corner, the 10 would move the man back one space because the man cannot be moved 10 spaces forward and all other men are on start.

When you move backwards from start, you can go into your home.  You'd need to get as many spaces or less as it is from that space to the home spot.  Otherwise you'd forfeit your turn.


text:
Can Aphotic Wisps be cast on a black creature that has fear?
As the title asks, can I cast Aphotic Wisps on a creature like Dross Prowler that already has fear and is already black?
In the same vein (I don't see why it would be different, but Magic is complex), can I cast 2 copies of Aphotic Wisps on the same creature and will they both resolve?

@Gendolkari Thanks for the edit! That "mtg:" markup is a pretty nifty trick.

You can target any* creature, it doesn't matter if the creature is black and/or has fear. This is because all the card says is "Target creature", not something like "Target non-black creature without fear". Dross Prowler is a creature thus it is a valid target for "Target creature".

114.1a An instant or sorcery spell is targeted if its spell ability identifies something it will affect by using the phrase “target [something],” where the “something” is a phrase that describes an object, player, or zone.

*barring things like hexproof, shroud and protection

Sure, there's no reason you can't do that. All Aphotic Wisps requires is a "target creature", it doesn't care what color it is, or what abilities it has. You could cast as many Aphotic Wisps as you want on the same creature and they'll all resolve, but only the first one to do so will change the properties of the target creature. You will get to draw a card for each Aphotic Wisps that resolves, though.


text:
How do "Maro" effects work when you cast your last card to pump them?
If a creature's power and toughness are equal to number of cards in your hand (e.g. Maro), and if I play an enchantment from my hand giving that creature +3/+3 leaving no cards in hand, will it make the creature 0/0 before the enchantment resolves?

Hi, Ash, this is a really good question, with a title that hides how good it is (because we get a lot of "Magic: the Gathering" questions on here). I've suggested an edit, and added a link to cards of this type.
Feel free to rollback if you don't like the edit.

Yes, the creature would die.
When you cast a spell, you move it from your hand to the stack, and other players get the chance to react to that spell. State-based actions would cause the creature to die.
Rules references:

Casting Spells

601.2. To cast a spell is to take it from where it is (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect.

That means the card goes from your hand to the stack and will no longer count toward Maro's ability. But even though it's 0/0 at this point, it's not quite dead yet.

601.2h Once the steps described in 601.2a–g are completed, the spell becomes cast. Any abilities that trigger when a spell is cast or put onto the stack trigger at this time. If the spell’s controller had priority before casting it, he or she gets priority.

Every time, whenever a player gets priority, state-based actions are checked first:

State-Based Actions

704.3. Whenever a player would get priority (see rule 116, “Timing and Priority”), the game checks for any of the listed conditions for state-based actions [..]

704.5. The state-based actions are as follows:

704.5f If a creature has toughness 0 or less, it’s put into its owner’s graveyard. Regeneration can’t replace this event.

If the spell you cast was your last card in hand, and Maro goes to zero toughness, it will die as soon as you finish casting that spell. By the time it can resolve, Maro is already moved from the battlefield to the graveyard.
Note that there are certain spells that require you to discard cards, then draw one or more, such as Windfall or Wheel of Fortune. Those cases are different. During the resolution of such spells, you temporarily go to zero hand cards as well, and Maro goes to 0/0 temporarily, but state-based actions are not checked during resolution, and Maro will not be destroyed because of such a spell:

704.4. Unlike triggered abilities, state-based actions pay no attention to what happens during the resolution of a spell or ability.

Recommend referencing the appropriate rule, 704.3

I read your answer.  Made total sense.  But then the ruling on Maro confused me.  Is it worth a new question?  Or is it possible to clarify your answer wrt that context?  (I don't see how number of cards in hand can change during announcement or resolution of a spell.)

@john the stack is a zone, like battlefield or hand. If you cast a spell from your hand, it moves from your hand to the stack and stays there until it resolves or gets countered, so it no longer counts for maro.

Thanks.  Not quite my question though.  Here's a quote from the rulings for Maro:  "If Maro’s toughness goes to 0 during the announcement or resolution of a spell or ability and then goes back up above 0 before the end of that announcement or resolution, it won’t be put into your graveyard when state-based actions are checked."  How can that happen?

It went to zero before the spell resolves. The ruling refers to spells like Wheel of Fortune or Windfall, where you go to zero hand cards during spell resolution, not before. I guess I'll add the rules though, since it seems to create confusion still.

@John As an example of the number of cards going back up above zero during the announcement of a spell, consider the spell Daze. If you cast it for its alternate casting cost, you put another card into your hand while you're casting it.


text:
Does Medomai the Ageless + Supplanter of Identity give me infinite turns?
A few days ago a new card named Supplanter of Identities was spoiled and I was wondering if you would target Medomai the Ageless with the effect of the supplanter you could take infinite turns (if you get through).
A problem I could see with this theory is that Medomai might come back before the Supplanter changes back, making the legendary rule kick in, but I'm not sure if it works like that.
So my question is if this interaction works the way I think.

If you copy a legendary creature with Supplanter of Identity, the exiled creature will return first and the legend rule kicks in.
In the turn structure, the last two steps are the End step and the Cleanup step. The creature exiled with Supplanter of Identity returns at the beginning of the end step, but Supplanter of Identity itself will remain a copy of that creature until the Cleanup step, causing the legend rule to apply.

Ending Phase

512.1. The ending phase consists of two steps: end and cleanup.

End Step

513.1. First, all abilities that trigger “at the beginning of the end step” or “at the beginning of the next end step” go on the stack. (See rule 603, “Handling Triggered Abilities.”)

513.2. Second, the active player gets priority. Players may cast spells and activate abilities.

This is where the exiled legendary returns. The return trigger resolves, players would get priority, the legend rule (a state-based action) kicks in.

704.3. Whenever a player would get priority (see rule 116, “Timing and Priority”), the game checks for any of the listed conditions for state-based actions,

704.5k If a player controls two or more legendary permanents with the same name, that player chooses one of them, and the rest are put into their owners’ graveyards. This is called the “legend rule.”

Lastly, the Supplanter returns to its original, if it's still on the battlefield.

Cleanup Step

514.2. Second, the following actions happen simultaneously: all damage marked on permanents (including phased-out permanents) is removed and all “until end of turn” and “this turn” effects end. This turn-based action doesn’t use the stack.

Note that if there is a Mirror Gallery in play, your combo would work. Medomai's limitation of being unable to attack during extra turns only means it can't be declared as an attacker. However, it is the Supplanter that would be declared, who has no such limitation. The act of declaring it as an attacker triggers the its copy ability. Only now would it become a copy of Medomai, and it would keep attacking and creating extra turns.

Wouldn't the combo also not work because Medomai says it "can't attack during extra turns"?

@Dennis_E No, that wouldn't have an effect. "Can't attack during extra turns" only means it can't be declared as an attacker during extra turns. However, the Supplanter is already attacking when it copies Medomai. It's not removed from combat or anything.

I totally missed the fact that the copying happens during combat. This makes sense then.

I'm a bit bummed to find out the legendary rule stops this combo, but still I'm still happy with finding this neat interaction

It will work if  Medomai is owned by the other player.