text:
Does Grindclock's counter reset when it's activated?
When a player taps the Grindclock ability to pull X cards from a player's library and place them in the graveyard, does the counter reset?

And this was a bad question why?

This question can basically be answered by "just do what the card says", so some people might see it as a lack of trying.

It was a question that came up during play and no one knew the answer.  Since there are cards that don't always act like what they tell you to do, it seemed relevant. @ikegami responded in the apporpraiet manner.  Whomever voted it down did not.

It's a poor question because it is uninteresting and poorly considered. What about the ability would remove the counters? Activating an ability? Tapping? Setting X? Targeting? Removing cards from a library? Putting cards in a graveyard? There's absolutely no reason to believe it would remove counters except that someone wants it to do so. Sure, you can ask for confirmation and we'll answer you, but it's still a poor question.

Actually, balance of card power in the game would suggest it not maintain its' counter.

Totally unfounded in anything but feelings.

It is clearly not totally unfounded since they have removed cords from play in play formats for that very reason.  As to playing a card as it says to be played, that can be a bit baffling to people.  Consider: http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Ice Cauldron

@StephenWinburn If you added a good reason for why you think the counters would be lost, I would retract my downvote. "It seems overpowered." is a bad reason. "Cards in general are not what they appear." is also a bad reason. I'm left wondering how you play Magic if you are this cautious of every card.

@StephenWinburn Ice Cauldron still does exactly what it says (or at least exactly what the oracle text says). It may be a little hard to figure out at first, but it's not ambiguous, and neither is Grindclock.

@StephenWinburn: "there are cards that don't always act like what they tell you to do" — Name one.

It seems the counter builds up as a costs that should be expended and rebuilt.  This is logical.  The alternative is not.  Otherwise it would imbalance play.  Examples of cards not reprinted due to causing power imbalances include the Power of Nine and Black Lotus. The latter is also an artifact, and suffers the same possibility for defeat during play.

@StephenWinburn But the counters don't build up as a cost. It's a card that slowly gets more powerful over the course of the game. It's not imbalanced because it's pretty slow, and mill is hard to win with.

Here is a article (research paper) on such imbalances of power that addresses magic as one of its focuses.

I'd suggest moving the discussion of power imbalances to the chat room, because it is only tangentially related to the question. The important question in these comments is what made you expect that the card did not behave as printed. And, relatedly, jwodder's question.

@StephenWinburn Actually, while the power 9 are certainly overpowered, the real reason they are not reprinted is due to their being on the reserved list. If you're looking for an example of a card that won't be reprinted --only-- for power level reasons, I would consider Jace the Mind Sculptor as your posterboy. To quote Mark Rosewater "Standard has never been at a power level where Jace, the Mind Sculptor was not over powered. (Well, maybe Standard with Urza’s Saga block.)"

In MTG, counters are physical markers that are counted, added and removed; they are not abstractions that store a number that can be manipulated. As such, it makes no sense to talk about resetting a counter; you want to know if the counters are removed.
Nothing instructs you to remove the the counters, so you do not remove them. Just like attacking doesn't remove +1/+1 counters, using Grindclock's ability does not remove charge counters.
Things that remove counters.

The counters on Grindclock do not reset. In fact, "Reset" is not a special keyword that means anything to a Magic player. The short answer is that if nothing says to remove counters, they don't get removed. The long answer is that they remain until one of two things happen:

An effect removes the counters
The object upon which the counters were placed cease to exist

An example of the first bullet is Power Conduit, which has an activated ability that removes counters. Coincidentally, it creates counters that are interchangeable with those generated by Grindclock.
An example of the second bullet would be if I cast Naturalize on your Grindclock. Your Grindclock would be destroyed. Any counters on it cease to exist. This is not the same as "removing" counters.

By the way, you mentioned a downvoter earlier... When I vote, I vote on the post's merits. It wasn't me; the small error is not enough to merit a downvote.

@Ikegami I think it's fair to say Rainbolt isn't implying that. The question is "Does this card get its counters reset?" This answer says "No it doesn't." It then goes on to say that nothing else does except for when it says so, which is about as general a statement as one would expect. If there's a general implication here that other cards reset their counters, that's accurate, because some other cards do. Except they say so, as this answer goes on to say.

@ikegami So do you have a suggestion for improvement, as is the point of.comments?

@ikegami Sounds ok. That plus "and there's no such thing as counters resetting" I guess?


text:
Are the odds of drawing mythics greater when purchasing individually packaged boosters over booster boxes?
From personal experience I tend to draw mythic rare cards about one in five purchases when buying individually packaged boosters at Target, Walmart, etc, like the ones in this picture:

In booster boxes I have never gotten more than 6 mythics. This led me to think about this for a moment. If Wizards can profit more from individually packed boosters, wouldn't they want to have people draw mythics more often from them? My reasoning is that a non-serious gamer would not buy a booster box, but would be more likely to buy individual packs. If this person gets mythics with just a few packs, that would be a good incentive to come back for more.
So my question is this: Are the odds of drawing mythics greater when purchasing individually packed booster card packs over booster boxes? Has anyone ever compared the odds? (I'm not quite ready to shell out $1000 to find out.)

Booster packs come from boxes.

If your experience is truly one in five single booster pack purchases gets you a mythic rare, then you are simply lucky with a small sample set. One in Eight rare cards in a booster pack will be a mythic rare. Since there are 36 boosters in a box, you should only expect to get 4-5 Mythic Rare cards.

Please ask about the boosters inside premade decks in a separate question: that's a different scenario to the trivial scenario of booster boxes. (Though the answer might be they're exactly the same, again.) The edit you made to your question is still visible in its edit history.

Oh, are you actually asking about premade decks when you refer to "individually packed packs", not individual boosters purchased entirely on their own?

Yes. Apologies for not being clear. But I wouldn't say it is a premade deck - there is just one booster pack inside all that cardboard.

@DavidVogel Aha, now I understand what I'm looking at. I've never seen those in Australia. I've edited your question.

No, there's no difference.
The foil boosters purchased individually from your Friendly Local Gaming Store's shelf are exactly the same as the ones in the booster box, except they unpack them from those boxes first and put them on the shelves. You have an equal chance of getting a mythic from any of them.
As for boosters wrapped in cardboard, they say "New look, same booster pack!" - if it's the same booster pack, it should be the same again.
If you have better luck getting Mythics from one kind of booster than the other, you may either have been fairly lucky in that regard, or you're just perceiving it that way and really there's no difference and you haven't noticed it because you haven't been recording things rigorously.

That makes sense. I feel I need to clarify the question though and included a picture in it. Do these individually packaged packs have the same odds as what comes out of booster boxes?

@DavidVogel Are there any booster boxes filled with those individual packages?

One supposes only someone who works at Hasbro or CartaMundi could tell us for certain.  But, cards are printed in pre-set sheets and cut up, they don't come out of the printer one at a time.  Consider if you really think Hasbro would go to the trouble and expense of creating a different set of printing templates + whatever else to create a different set of sheets that have differently weighted distributions of cards on them just for that small run of individually wrapped packs?  (also... it's tough to think they earn a higher margin on anything sold at Walmart of all places!)

If you buy individual booster packs from any vendor you don't trust, you may be less likely to pull a mythic rare because of the existence of a technique known as box mapping. So in an ideal world, yes, this answer is correct. In reality, some FLGS owners are greedy. I think box mapping should at least be noted somewhere for completeness, as it could absolutely explain the discrepancy. My local game store opens brand new boxes for each draft because of this, and sells the remainder on the shelf (because box mapping is ineffective when half the box is missing).

The only differences between single packs out of a booster box at a LGS and blister packs at a big box store are:

The blister packs can't really benefit from mapping1 like the boxes for some sets can.
People can more easily steal cards out of the blister pack and repack them with terrible cards not even in the same set.

Number 2 is especially true if the blister pack comes from Walmart, who have a very generous return policy.
Normal2 MtG packs have a 1/8 chance to contain a mythic (roughly, depending on the size of the set), regardless of where the pack comes from.

"Mapping" a set means determining how the cards in the set are printed and distributed (a process that is generally crowdsourced). Once the set is mapped, one can potentially open a small number of boosters from a box and from there determine what every rare in the box is, and which packs have them. Mapping does not generally cover foils, however. Wizards has spent great effort to prevent the capability of mapping sets, and these days while it is still possible, it is generally unprofitable.
By "normal," I mean to exclude things like special packs used for prereleases such as the guild-specific packs in the Return to Ravnica block. I am not certain on their mythic distribution, so I'll not comment on them.

It would be very hard to extract cards from one of WotC's 'individually wrapped' boosters of the sort shown in the photo, re-seal the foil booster wrapper, reseal the cardboard, and return it to Wal-Mart.  I can't imagine this is a positive-value proposition.

I've seen reports on MtG forums of exactly that occurring, actually. I won't speculate on the value gained from the theft, but people do it. Some thieves go to extreme lengths for this type of activity, even as far as having their own shrink-wrapping machine for video games.

source: Stack Exchange

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

sort: votes


text:
How can make a balanced equipment deck with seasons 1 and 2, and TCM?
When playing with both season 1 and 2, and TCM, what is the best way to build the equipment deck so it is not unbalanced? It seems like the likelihood of drawing a three damage weapon is quite low with all the cards together.

Why? It's been a while, but I don't seem to remember a reason to mix S1 and S2 together. Just use one of them.

@ikegami Some weapons are exclusive to each such as pans, night sticks and the concrete saw to name a few

There are no pans or nightsticks in the deck. Those are starting equipment. My question stands.

@ikegami There are more than three pans in the deck. One might want the variety of various weapons such as the nightsticks or riot shields as mentioned earlier. A better way to look at the question would be if the decks are already combined how should they be broken down?

Not when I play. They're just starting equipment as far as I'm concerned. The nightsticks replace the pans, and it would be silly to play with both. So, that leaves you wanting to use riot shields and a concrete saw. That's not a reason to mix the two decks. Either use the deck that has them, or adds those to the other deck.

Your interpretation of the rules doesn't really answer my question nor does it make sense to say using both would be silly because that's just an opinion

Then why are thier more than three?

I counted there are 8 pans. There would be no reason to include them if you war only going to use three.

There are three pans in S1, allowing for 6-player games. 4 were added in TCM allowing for 10-player games. The rules literally say "Put aside the [...] Pan [...] cards."

That makes more sense thank you for explaining that.

It seems like the likelihood of drawing a three damage weapon is quite low with all the cards together.

S1 alone is the worst. S1+S2 is about the same as just S2. Adding TCM greatly improves the odds.

S1: 2/52 = 3.8% (2 sets of Molotov ingredients)
S2: 3/71 = 4.2% (2 sets of Molotov ingredients, Concrete Saw)
S1+S2: 5/123 = 4.1%
S1+TCM* = 5:/69 = 7.2% (2 sets of .44 Magnum + Hollow-Point Rounds, Flamethrower)
S2+TCM* = 6/88 = 6.9%
S1+S2+TCM* = 8/140 = 5.7%

TCM* = TCM excluding Ultrareds.

A better way to look at the question would be if the decks are already combined how should they be broken down?

S1 - 62 equipment cards

52-card deck:

4x Aaahh!
3x Bag of Rice
2x Baseball Bat
3x Canned Food
2x Chainsaw
1x Crowbar
1x Fire Axe
2x Flashlight
2x Gasoline
2x Glass Bottles
1x Goalie Mask
2x Katana
4x Machete
2x Pistol
3x Plenty of Ammo (bullets)
3x Plenty of Ammo (shells)
2x Rifle
2x Scope
4x Sawed Off
2x Shotgun
2x Sub MG
3x Water

Set aside:

1x Crowbar
1x Evil Twins
1x Fire Axe
1x Ma's Shotgun
2x Molotov
3x Pan
1x Pistol

TCM - 23 equipment cards (itemized in the rulebook)

17 cards to add to deck:

2x .44 Magnum
2x Assault Rifle
2x Cookies
2x Gas Mask
1x Flamethrower
2x Hollow-Point Rounds
4x Laser Pointer
2x Spare Change

6 Ultrared cards to add to deck:

1x 911 Special
1x Betty
1x Doug's Dream
1x Jack & Jill
1x Ned's Atomic Flashlight
1x Sweet Sisters

Set aside:

1x Pa's Gun
4x Pan

S2:PO - 83 equipment cards (itemized in the rulebook)

71-card deck:

2x Automatic Shotgun
4x Aaahh!
3x Bag of Rice
2x Baseball Bat
3x Canned Food
2x Chainsaw
3x Claw Hammer
1x Concrete Saw
1x Fire Axe
2x Flashlight
2x Gasoline
2x Glass Bottles
4x Hatchet
2x Katana
4x Kukri
2x Meat Cleaver
2x Nails
5x Pistol
3x Plenty of Ammo (bullets)
3x Plenty of Ammo (shells)
2x Rifle
2x Riot Shield
4x Sawed Off
2x Scope
2x Shotgun
2x Sub MG
2x Wakizachi
3x Water

Set aside:

2x Gunblade
2x Nailbat
3x Nightstick
2x Molotov
1x Claw Hammer
1x Fire Axe
1x Pistol

Found out that all of Chainsaws were in my S1 pile, and a set of S1 starter weapons (Fireaxe, Crowbar and Pistol) were in S2 pile. So this was useful :)

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


text:
How should we be keeping track of secret doors?
How are players keeping track of which doors a player has uncovered? Once you have discovered a door you do not need to roll again to find it. It seems like a lot to memorize or are we playing this game wrong?  Do all four get the knowledge of the door once uncovered?

Assuming you are playing the new WotC version, the rules state

You might wish to keep track of the doors you found on a piece of
  scrap paper

Now all you need is some way to easily reference a specific door.  You could try to describe the area it is in, like "Door to east-most level 4 room".
Of course, if you're playing the older "New Dungeon", it wouldn't really be a problem, because in that version you forgot about secret doors as soon as you moved away from them.

Ok thanks.  At least I know I am not doing something wrong

I think I need to write an app for this maybe


text:
"Stay Away" how to handle case with 4 Infected cards
Last night I had a game where I was infected by The Thing and drew a Panic! card (Forgetful) which states that I should discard 3 cards and draw 3 more. What happened was that after that Panic! card I had to discard my 3 not infected cards (since I am infected I can't discard the one I have) and I drew 3 Stay Away which happened to be infected cards so I was left with 4 infected cards, but the rules state that you can't have more than 3 in your hand in any given time.
What I thought of was that if a Panic! card doesn't say that it ends your turn you can draw again and continue as normal, but that is not also a viable solution to the problem, because the next card might still be Infected.
Has any of you encountered this situation? Can you give me an idea of what solution I may apply to this bug?

My suggestion/workaround is to show everybody that you drew 3 'infected' cards, discard them and draw 3 more cards instead whether you're infected or not. If it's infected cards - do it again.
And yes we actually encountered this situation and it kind of messed the game.


text:
Is it worthwhile to build a competive Standard M15 deck when a block is about to rotate out?
So I want to start playing competitive magic again, in the standard format (just started up again after about 6 years of not playing).
Is it worth it for me to build a competitive standard deck right now, considering that the RTR block will be rotating out and most competitive decks contain RTR cards? Or should I just play draft right now to build up cards that will be in the Theros block and will still be legal In standard play come this fall, and wait to see what decks are still competitive this fall after the new set rolls in?

"Should" by what standard?  We need to know what you want out of Magic before we can tell you how to get there.  How many games do you want to play, and how often?  How many do you want to win, and how often (and how soon)?  How much money do you have to blow?  Etc.

Well, there's standard tournaments at my local shop every Friday and Sunday that I'd like to attend. I would like to win them all lol. And I'm not rich, but I've got some extra money to put towards. Essentially I feel like id waste my money building a competitive deck right now, especially with cards that are about to rotate out. So I suppose my goal would be to gain as many cards that will still be relevant in a month out of M15 and theros block.

I would seriously consider waiting for the rotation. Two, possibly three of the major decks (namely U/W Control, Mono-Black Devotion and possibly Mono-Blue, whose competitiveness will depend on on the strength of red in Tarkir block) will be completely transformed or outright lost to rotation.
I would focus on getting the key cards from Theros block/M15 that are safe vet to be used in decks after rotation. Stuff like Hero's Downfall, Sylvan Caryatid, Courser of Kruphix, Stormbreath Dragon, Nissa, WorldWaker, Elspeth, Sun's Champion etc.


text:
Can I bring Blightsteel Colossus back to my graveyard before it gets shuffled into my library?
If I discard a Blightsteel Colossus and the "Shuffle into library" trigger goes on the stack, can I, in response, do something to bring it back from my graveyard before it gets shuffled, such as by Cloudshifting Sharuum the Hegemon?

No. Brightsteel Colossus does not have any triggered abilities. Those start with "when", "whenever", or "at". Its last ability is a static ability that creates a replacement effect. You can tell because it uses "instead". It changes what it means to discard Brightsteel Colossus. Brightsteel Colossus never enters the graveyard when it is discarded.

112.3c Triggered abilities have a trigger condition and an effect. They are written as “[Trigger condition], [effect],” and include (and usually begin with) the word “when,” “whenever,” or “at.” Whenever the trigger event occurs, the ability is put on the stack the next time a player would receive priority and stays there until it’s countered, it resolves, or it otherwise leaves the stack. See rule 603, “Handling Triggered Abilities.”
614.1. Some continuous effects are replacement effects. Like prevention effects (see rule 615), replacement effects apply continuously as events happen—they aren’t locked in ahead of time. Such effects watch for a particular event that would happen and completely or partially replace that event with a different event. They act like “shields” around whatever they’re affecting.
614.6. If an event is replaced, it never happens. A modified event occurs instead [...]

No.  Blightsteel reads:

If Blightsteel Colossus would be put into a graveyard from anywhere,
reveal Blightsteel Colossus and shuffle it into its owner's library
instead.

This is a replacement effect, not a triggered ability ("instead" is the giveaway).  Consequently, it doesn't use the stack, and can't be responded to.  Additionally, Blightsteel never actually goes to the graveyard, and so isn't ever there to be a valid target for Sharuum's ability.
Serra Avatar has a different variant of the ability that you could respond to:

When Serra Avatar is put into a graveyard from anywhere, shuffle it
into its owner's library.

Because this has the word "when", it is a triggered ability, and you could resurrect Serra Avatar by using Cloudshift on Artisan of Kozilek, Doomed Necromancer, or some other instant speed resurrection ability.


text:
Does Humility affect the graveyard?
Does Humility effect cards in the graveyard? (EX. If Humility in play, can I discard Blightsteel Colossus without the shuffle?)

How do I add links again?

[mtg:Card Name]

No, it only affects creatures, which is to say creature cards and tokens on the battlefield.

109.2. If a spell or ability uses a description of an object that includes a card type or subtype, but doesn’t include the word “card,” “spell,” “source,” or “scheme,” it means a permanent of that card type or subtype on the battlefield.
110.1. A permanent is a card or token on the battlefield. [...]

If Brightsteel is in play with Humility and dies, at what point does the card regain its ability? Would it go into the graveyard?

@Samthere http://boardgames.stackexchange.com/q/6505/2474


text:
Can I imprint my Commander onto Mimic Vat, and still take it back to the Command Zone?
If I am playing a Sharuum the Hegemon EDH deck, can I let my commander go to the graveyard, exile it under Mimic Vat and then put it into the command zone but still have it imprinted, or does the fact that that is a replacement effect make it so it isn't imprinted.

No.

607.2a If an object has an activated or triggered ability printed on it that instructs a player to exile one or more cards and an ability printed on it that refers either to “the exiled cards” or to cards “exiled with [this object],” these abilities are linked. The second ability refers only to cards in the exile zone that were put there as a result of an instruction to exile them in the first ability.

There are no cards in the exile zone, so there is nothing to copy.

I'd mention something about not being able to have a cake and eat it too, but that expression never made any sense to me.

the original quote was "... eat your cake and have it too" some how it got reversed while retaining the original  meaning!


text:
Can I get an enters-the-battlefield effect out of a second legendary before I must sacrifice it?
If I have a legendary creature out, and I make a copy of it (such as by enchanting it with Splinter Twin or making a Clone), do I get enters-the-battlefield effects from the creature before I have to sacrifice it to the legend rule?

Yes.
As discussed in an article discussing the recent Legendary rules change:

This will allow you to somewhat mitigate the downside of drawing a second copy of a Planeswalker by playing that copy to, in effect, refresh the loyalty of a Planeswalker or to get a second enters-the-battlefield trigger on a legendary permanent.

Here's the rule covering Legendary permanents:

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.”

Note that in order for the Legendary state-based action to be triggered, the Legendary permanents are both already on the battlefield and therefore any triggered enters the battlefield abilities (ETB) are also triggered. As the Legend rule is a state-based action, the choice of which Legendary permanent will be kept will be made before the ETB triggered abilities are put on the stack and resolve.

Slight timing nitpick: the ability triggers before SBAs are checked, but is technically placed on the stack afterwards. I can't think of a scenario where the exact order matters though.

@MichaelSnook - you have to declare targets when an ability is put on the stack. That the "legendary rule" effect happens before triggered abilities are put on the stack is what allows Sharuum + Sculpting Steel to go infinite.

@Hao You'd think I would remember that since one of the people I play with has a Sharuum deck

So to be clear, one of the legendaries is discarded immediately when checking state-based actions after the abilities go on the stack but before they resolve?

@MichaelSnook Thanks for the catch! I've reworded the offending paragraph so that Sharuum isn't sad.

@Samthere As Michael pointed out, you actually discard one of the legendaries before any ETB triggered abilities are even put on the stack.

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


text:
How many Auras can enchant one Creature?
I played Magic: The Gathering with couple of friends.
I was asked a question when we came to a situation where we could put two Auras on one Creature. Can one enchant a create with more than one Aura?

You can have any number of Enchantments attached to a given Creature, unless the cards themselves say otherwise.

Also Gatherer of Graces and Auramancer's Guise would be useless if it wan't possible

@IvoBeckers, Daybreak Coronet would be even more useless, since it can't even remain attached to a creature that doesn't have another aura attached.

It wouldn't even be possible to play Daybreak Coronet at all.

@murgatroid99, It's worse than not being able to play it. You can't even attach it through an effect such as Sun Titan. Daybreak Coronet also gets dumped into the graveyard if it becomes the only aura on a creature.

Sure you can!
That's it, if the cards don't state otherwise and the creature is a valid target for every one of the enchantments. And as you can cast several enchantments on the same turn you even can do it on just one turn.There's no a thing like a 'limit' on the number of enchantments one can cast over a given creature.
Just consider strategic-wise if it's convenient for you to put two or more auras on a creature that could be wiped out by a single card from your adversary.

It is applicable to creatures only. But for Global Enchantment based on the old rule of MTG from 4th to 5th edition, you can only play one enchantment per type per game. for Example, you can play one pestilence during the game and can no longer play another one while it's still in play (because it doesn't make sense right?). I never saw another rule out there that overrides this rule but I'm seeing a lot of players who does not abide by this rule.

I'm pretty sure this was never true of enchantments in general. There are specific enchantments called World Enchantments (originally "Enchant World") such as Concordant Crossroads, and only one of those can be on the battlefield at a time.

Yes, I believe you've confused World Enchantments with regular enchantments. You certainly can have multiple Pestilences on the battlefield at once, and you've always been allowed to. Though you're right that in general, having multiple of that specific one isn't helpful.

This was only ever true of cards typed "Enchant World" A lot of enchantments would be redundant to have multiple copies of out, but just because it doesn't make sense to play that second pestilence doesn't mean you aren't allowed to, just that it'd be a bad idea to do since you'd have to sacrifice both when there are no creatures left.


text:
Conditions about returning Chandra's Phoenix in one's hand
My opponent and I encountered a problem.
I had a Volcanic Geyser, which let me choose to deal damage to an opponent Creature, or the opponent Player.
I also had a Chandra's Phoenix in my Graveyard, when I cast the Geyser on my opponent's Creature.
Now I am asking about the Phoenix's text. It says:

Whenever an opponent is dealt damage by a red instant or sorcery spell you control or by a red planeswalker you control, return Chandra's Phoenix from your graveyard to your hand.

Does it mattere if I deal the damage to a opponent player or an opponent creature? Can I choose which one I deal damage to, and still fulfill the conditions to return the Phoenix in my hand?

Opponent only refers to players, not creatures. Chandra's Phoenix will not trigger if you target a creature.
Comprehensive Rules reference:

102.2. In a two-player game, a player’s opponent is the other player.
102.3. In a multiplayer game between teams, a player’s teammates are the other players on his or her team, and the player’s opponents are all players not on his or her team.

Chandra's Phoenix's ability triggers whenever an opponent is dealt damage by ...

102.2. In a two-player game, a player’s opponent is the other player.
102.3. In a multiplayer game between teams, a player’s teammates are the other players on his or her team, and the player’s opponents are all players not on his or her team.

You would have to target and deal damage to your opponent using Volcanic Geyser, not one of his creatures.

Chandra's Phoenix won't trigger if you deal damage to an opponent's creature. You have to deal damage to the player himself.


text:
Don't the Planeswalkers in Commander 2014 that say they can be your Commander contradict the fact the Commanders have to be legendary creatures?
Ob Nixilis of the Black Oath and the other Commanders in Commander 2014 say they can be your Commander. Doesn't that contradict the rule that Commanders can only be Legendary Creatures?

The very first of Magic's Golden Rules:

101.1. Whenever a card’s text directly contradicts these rules, the card takes precedence. The card overrides only the rule that applies to that specific situation. The only exception is that a player can concede the game at any time (see rule 104.3a).

So yes, they contradict, and it's fine. And this isn't really unusual; tons and tons of cards have text that effectively says "now the rules work a little differently, and here's how." For an extreme example, the rules say you lose the game when you're reduced to 0 or less life, but Platinum Angel says you can't lose the game, and it takes precedence.

[Ob Nixilis wasn't Legendary at the time this answer was written, but every Planeswalker was subsequently made Legendary. The question and answers are still pertinent because Ob Nixilis is still not a creature.]
Yes[1]. Commanders are normally Legendary Creatures, and Ob Nixilis is neither Legendary nor a Creature.

903.1. In the Commander variant, each deck is led by a legendary creature designated as that deck’s commander. [...]

But that's fine because of the first Golden Rule of Magic:

101.1. Whenever a card’s text directly contradicts these rules, the card takes precedence. The card overrides only the rule that applies to that specific situation. The only exception is that a player can concede the game at any time (see rule 104.3a).

If it didn't, there would be no reason to put that ability on the card.

Can I suggest updating the first line (after the italics) to say "and Ob Nixilis is not a Creature."? That renders the italic section unnecessary and brings the answer fully up to date.


text:
Can I cast a spell if I might be able to pay its cost but don't know yet?
A Wizards forum thread had an interesting question that was left unanswered.  If I have only two black mana available, can I cast Fatal Lore if my opponent has a Spellwild Ouphe on the battlefield?  The issue is it is a legal play only if my opponent chooses the destroy creatures option (since I could target the Ouphe, making it cost two lest to cast).

Nice question. Things do work in the right order to enable this question: first you make mode choices, then you choose targets, then you pay mana.

@doppelgreener It's worth noting that most of the other similar situations (that theoretically worked for the same reason) in that thread were shot down as misuses of rule 717.

On the other hand, this specific case doesn't really have a one-sided upside - you're basically revealing a card from your hand and offering the two creatures for three cards deal to your opponent, so it's not an abuse of the rules like a lot of the other situations.

Since it is a legal play under some outcomes of the process of casting it, it is a legal play.  If your opponent chooses the mode where you draw cards, it will become an illegal spell and the game will be reverted to the state it was in before you began casting it.
The precedent for this comes from a card specific ruling on Selvala, Explorer Returned:

If you activate Selvala’s ability while casting a spell, and you
discover you can't produce enough mana to pay that spell’s costs, the
spell is reversed. The spell returns to whatever zone you were casting
it from. You may reverse other mana abilities you activated while
casting the spell, but Selvala’s ability can't be reversed. Whatever
mana that ability produced will be in your mana pool and each player
will have drawn a card.

From this, we can tell that you are allowed to cast spells you might be able to pay for.
As Hackworth and various members on the forum point out, the rules do not explicitly prevent you from attempting to cast spells you have no way of paying for in any circumstance, but doing so doesn't ever help you.  At best, it reveals a card in your hand with no other consequence.  At worst, it could get you disqualified in a tournament for repeat offenses of slow play or cheating (if you are attempting to cast an illegal spell to make an opponent reveal information in their reaction).

Good answer, I liked the Selvala citation. Just a clarification though: Casting a spell or activating an ability is considered legal until the opposite is shown, not the other way around as your first statement seems to imply. There is no obligation to "look ahead" and determine whether there is an illegal step before you get to such a point. Of course, if you make it a habit to make illegal plays over and over, you might be punished for slow play or something in high REL, but that's another matter which the CompRules don't care about.

@Zags May wish to look to rule 717 for a reference to the Comp Rules for this.

@Hackworth Actually the rules do go into that. If you have infinite mana, and Fatal Lore is the only card in hand: "716.3. Sometimes a loop can be fragmented, meaning that each player involved in the loop performs an
independent action that results in the same game state being reached multiple times. If that happens,
the active player (or, if the active player is not involved in the loop, the first player in turn order
who is involved) must then make a different game choice so the loop does not continue."

@Waterseas Yes, but that's the limited case of doing the same thing over and over again. I meant in the general case, where a player could play a different spell/ability illegally every time.

@Hackworth Hmm, not fully sure I follow.

Before this goes too off-topic/extended: join me in the chat room if you like http://chat.stackexchange.com/rooms/49/board-and-card-games

You should be able to cast it. When you declare that you want to cast it, you don't yet know whether it will be possible to pay, but it could be possible, depending on your opponent's choice. If your opponent chooses that you draw 3 cards, you won't be able to continue casting it. But if your opponent chooses the destruction mode, then you will be able to finish casting it.
It wouldn't make sense to prevent you from attempting to cast the spell simply because it's possible that you will fail to cast it, if it is also possible that you will be able to cast it.


text:
Why is 21 damage from a commander lethal?
In commander, there is the extra rule:

903.14a A player that’s been dealt 21 or more combat damage by the same commander over the course of the game loses the game

I am wondering as to the origins and intent of this rule.  Why is commander damage tracked separately per commander and why is 21 the particular number chosen to be lethal?

Motivation for the question:
This rule is incredibly cumbersome from a game tracking standpoint.  Even with just 4 players, it means that in addition to 4 life totals, there are 12 commander damage totals to track as well (or possibly even 16 commander damage totals if control changing effects are prevalent).  This takes the number of things that need tracking well out of range of most magic tracking apps and counter methods, making pen and paper or large dice piles the only good tracking options.
My playgroup finds this so cumbersome that we ignore the commander damage rule almost entirely (we consider 20 damage from a commander in a single hit as lethal, and otherwise don't care).  This decision was made under the key part of commander philosophy:

House rules or "fair play" exceptions are always encouraged if they
  result in more fun for the local community.

But this piece of philosophy also suggests that the commander damage rule originally was to create fair or at least interesting play.
Also, the number 21 is very odd in the context of magic.  Magic game constants, aside from starting hand size, are usually multiples of 10: 20 life in a normal game, 30 life in two headed giant, 40 life in commander, 60 card minimum deck size in a normal game, 40 card minimum deck size in limited, 100 card deck size in commander...
[I'm posting my speculations as an answer, but I would love an answer with authoritative or historical sources.]

Is this a rant disguised as a question?

It's not super ranty, exactly, but it does take a bit to get to the point - maybe you could simply summarize the first several paragraphs? "Here's the rule:  It's cumbersome to track extra life totals, and it's odd that the number isn't round like most things in Magic. I am wondering..."

I moved the actual question to the top

In a 4 player game, you conceivably need to keep track of 16 commander damage totals, since you might be attacked by your own commander (after some Mind Control-like effect).

@HaoYe Good point.  I will add it

the justification is to have a reliable way to end a game if some players go with infinite life, so it doesnt degenerates in a combo arms race of whose combo can kill the others first nor it forces everyone to play an infinite combo just in case

@Silver I don't see this as a good explanation because non-commander formats have no such rule despite being in most cases easier to execute an infinite life combo in due to being able to run four of each combo piece rather than just one.  There are also commanders that can't do combat damage (such as the Planeswalker commanders).

The original rules for Elder Dragon Legend Wars had the following as part of the rules:

players choose (or select at random) an Elder Dragon Legend as their army's leader. The dragon must be supported by creatures and spells corresponding to each of the Dragon's three specific casting colours.
Players designate and announce three of their creatures as "Warlords" and two creatures as "Captains". If an opponent destroys a Captain, the Captain's controller takes 2 damage, and the destroyer gains 2 life. If a warlord is destroyed, the controller takes 3 damage and the destroyer gains 3 life. And for an Elder Dragon, the controller takes 4 damages, the destroyer gains 4 life.

I'm not sure when or how the rules where modified to add the 21 damage rule, but I found an interesting thread on the MTG boards. Someone who goes by the handle TheTrueNub posted this:

Well, I can tell you why the 21-damage rule was put in place, anyway. It didn't start out as anything to promote certain archetypes like voltron. "Commander" as we know it was once "Elder Dragon Highlander," the reason being that you'd choose one of the five Elder Dragons of Legends block (Arcades Sabboth, Chromium, Nicol Bolas, Palladia-Mors, or Vaevictis Asmadi) as your commander. Each of these dragons are 7/7, therefore three successful swings equals 21 damage. Though nowadays you don't have to use an Elder Dragon as your commander, the "21 Elder Dragon damage rule" is still preserved to this day.

This makes sense to me. I imagine he "three swings rule" was a flavourful rule added to ensure a large multiplayer game didn't drag out for too long and that aggro strategies were viable. Without this rule, it's too easy to build a lifegain and/or control deck that wouldn't give combat-oriented decks a chance.

If this TheTrueNub actually knows what he's talking about, that quotation seems to pretty clearly answer the question.

Yeah, I've seen it elsewhere online, in a reddit thread, it seems to be common knowledge and makes sense. Originally an alternate win condition was three hits from a commander and you're dead.

I would guess that the commander specific damage would be to make combat-oriented commanders like Akroma, Angel of Wrath competitive with commanders with powerful abilities like Arcum Dagsson or Krenko, Mob Boss.  By having it be commander specific, it prevents this from tipping the balance too far in favor of the combat oriented commanders in a multiplayer game, as if there were multiple players trying to win on commander damage, they would have an advantage over the players not trying to do this.
As to 21, it should be substantially less than players' starting life total or else this would have no point except against life gain.  21 has the nice property that for every increase in the power of your commander, the number of turns needed to kill someone goes down (at least until you get past 7 power):
commander power | turns to kill
----------------|--------------
      1         |       21
      2         |       11
      3         |       7
      4         |       6
      5         |       5
      6         |       4
      7         |       3

This doesn't happen with nearby numbers.  With 20, there is no difference between a 5 and 6 power commander (they each kill in 4 turns), and with 22 there is no difference between a 6 and 7 power commander (they each kill in 4 turns).

The original design of Commander, back when it was only called Elder Dragon Highlander, had exactly 5 legal commanders, the 5 original Elder Dragons, all of them were 7/7 creatures - Arcades Sabboth, Chromium, Nicol Bolas, Pallaida-mors and Vaevictis Asmadi - 21 damage was exactly what 3 unblocked hits from these dragons did.


text:
Spy Kit and Leyline of Singularity
Spy Kit gives a creature the names of all non-legendary creatures.  Leyline of Singularity makes all creatures on the battlefield legendary.  If I have the Leyline on the battlefield, as well as a Grizzly Bears equipped with Spy Kit and then cast Storm Crow, does Grizzly Bears lose the name Storm Crow, or is one of the two put in the graveyard because of the legend rule?

They will conflict because of the legend rule.  Spy Kit gives a creature the names of all non-legendary creature cards that exist in Magic.  This can be found in the card ruling:

The set of names the equipped creature has includes the names of all nonlegendary creature cards in the Oracle card reference, including the back faces of double-faced cards.

Spy Kit is adding names based on the printed properties of those creatures, not the current properties of permanents with those names.  Storm Crow the card is not legendary, so Grizzly Bears is also named Storm Crow regardless of whether or not there is a Leyline of Singularity, and will have a legend conflict with a second Storm Crow if there is a Leyline of Singularity.

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


text:
Are you allowed to shuffle your library at any time?
Of course, there are some spell cards that allow you to look through your deck to find some sort of card, usually sorcery cards that let you find basic lands in your library or something and then shuffle it.
Anyway, what if I am in a situation where I seem to only be drawing cards that are too expensive in mana cost or I'm only pulling lands? Am I allowed to shuffle my library at any time, or do I have to deal with what I get or cast some kind of sorcery or instant that lets me find a card/cards then shuffle my library?

Even if you could, it wouldn't help. Assuming that you shuffled properly when instructed to (at the beginning of the game, or when a card said so), the pattern of cards you have previously drawn has no predictive power regarding the next card you draw. In other words, if you are "only pulling lands", you are no more likely to draw another land if you don't re-shuffle than if you do. And if you didn't shuffle properly before, there's no reason to assume that you will do so now.

@murgatroid99 True, except for the last sentence: "And if you didn't shuffle properly before, there's no reason to assume that you will do so now." People make mistakes. Assume for a moment you realize a turn after shuffling you made a mistake somewhere in the process. That would make this a legitimate question.

Do you have an actual concrete example? You don't accidentally stack your deck. You don't accidentally pile shuffle. You don't accidentally look at the cards and then accidentally fail to reshuffle. Shuffling isn't some complex process that you can invalidate by missing a step half-way through. You just riffle a few times.

@JoeWallis That's a very different question, one where the answer is basically "call a judge" or in casual play "pretend to be a judge." Keep in mind that if that does happen, you still broke the rules - it's just that it was an accident. If you do end up (re)shuffling your library, it's not because you're allowed to whenever you want, it's because it's the least bad way to remedy a mistake.

@JoeWallis My point is that that is not actually "legitimate". It's still breaking the rules. However you end up dealing with it, it's separate from this question, and separate from murgatroid's point about re-shuffling not helping the OP's problem (cards too expensive, too many lands).

I feel like Murgatroid's comment should be a part of an answer to this. Sure the question in the title as-asked can be answered with a simple "no" and a rules quote, but the question makes it clear that the asker is misunderstanding something fundamental about the way shuffling and randomization works if he thinks that reshuffling would address the issue he's having.

@GendoIkari I took your advice and expanded that comment into an answer

You can't shuffle whenever you want; rule 401.2 explicitly handles this case.

401.2. Each library must be kept in a single face-down pile. Players can’t look at or change the order of cards in a library.

Plus, if you could shuffle at will, it would make cards that let you shuffle like Ponder pretty redundant.

The real redundant card here is Myr Mindservant.

It would also make almost any card with "Play with top card of your library revealed" insanely overpowered.

Ponder wouldn't actually be redundant in this case.

And everyone would be playing Psychogenic Probe :) not really a fun alternative reality ...

@Autar: But the free shuffles wouldn't be caused by a spell or ability, and even if they counted, you'd need to make the opponent shuffle.

@user2357112 Oh you're right, doesn't work ... Well, one less crappy alternative reality to worry about :)

Absolutely not.
As a general rule of thumb, unless the rules say you CAN do something at a specific time, you can't.
You can only shuffle your deck before you've started your game or when a specific card tells you you can.  As a side note - if it doesn't say "may" when it talks about shuffling your deck, it's mandatory.
The exact rule was already added, so I'll just comment a bit more explanation:
There are far too many scenarios where the ability to shuffle your deck at any time would be game-breaking.  It would also take various 'punishments' of cards meaningless (ex: "Send a card to the bottom of your opponent's library").

You cannot shuffle whenever you want. As other answers have already pointed out, rule 401.2 says that you are not allowed to reorder your library.
I'll need this definition later, so I'll quote it now. The rule defining shuffling is 701.16a:

To shuffle a library or a face-down pile of cards, randomize the cards within it so that no player knows their order.

Even if you could shuffle whenever you want, it generally wouldn't actually help. To be specific, say you have 40 cards left in your library, and you just shuffled (perhaps because you just activated Evolving Wilds). Now, you know what cards are in your library, but by definition you don't know what order they're in. Then you draw a Forest, which you didn't want because you already have enough land. Now you still know what cards are in your library, because you can just subtract one Forest from the cards you knew were in there before. And you still don't know what order the cards are in. You know there was a Forest on top, but that doesn't help, because that Forest isn't in your library anymore.
Now imagine that you could shuffle your library right now. Obviously, the library now has the same cards as before. And again, by the definition of shuffling, you don't know what order the cards are in. And you should be able to see that this hasn't actually changed anything: both before and after shuffling, you know what cards are in the library, and both before and after shuffling, you don't know what order they're in.
Now, you might ask "But, if it doesn't change anything, why can't I shuffle whenever I want?" The answer is that I was describing the general case, and there are some cases where it does matter because you do know where some of the cards are. And then the ability to choose to shuffle would give you and advantage. [Jace, the Mind Sculptor]'s first ability would be completely useless if you could shuffle; your opponent could say "I leave that card on top" and then you could just say "Actually I'll just shuffle it away". Brainstorm would be much better if you could just draw 3 cards and then shuffle your 2 worst cards back into your library, instead of being forced to draw them back for the next two turns. Garruk's Horde would be crazy powerful: you could just shuffle until you see the creature you want, and then cast it.

No, you cannot shuffle your library at any time. Your opponent can force you to put "bad" cards on top of your library using spells such as Roil Spout, so it is strategically relevant.


text:
Does the attack or defender decide the order of damage assignment to blockers?
I read from the comprehensive rules guide that there is a damage assignment order, but I've always played the game as if there was a blocking order. Here is the relevant text:

509.2. Second, for each attacking creature that's become blocked, the active player announces that creature's damage assignment order, which
  consists of the creatures blocking it in an order of that player's
  choice. (During the combat damage step, an attacking creature can't
  assign combat damage to a creature that's blocking it unless each
  creature ahead of that blocking creature in its order is assigned
  lethal damage.) This turn-based action doesn't use the stack. Example:
  Vastwood Gorger is blocked by Llanowar Elves, Runeclaw Bear, and Serra
  Angel. Vastwood Gorger's controller announces the Vastwood Gorger's
  damage assignment order as Serra Angel, then Llanowar Elves, then
  Runeclaw Bear.

My interpretation of this is that I can attack with a 3/3 and the opponent can block with a 1/1 and a 4/4. I could make it deal the damage to the 1/1 first, and there is no blocking order such that the opponent can't say the 4/4 blocks first and 1/1 blocks second.
Is this accurate?

Semantics aside, I tend to conceptualize the damage-assignment order as the blocking-order, just that the attacker chooses that order. I could be in the minority on this opinion.

@corsiKa Yes, I've heard plenty of people refer to this as "[the attacking player] ordering blockers".

"Ordering blockers" is far more accurate. It necessarily implies you already have blockers. While "blocking order" could also mean that, it would require using a different definition of blocking than MTG does. The far more obvious implication of "blocking order" is that you are choosing the order in which things will block, which is incorrect.

I'll add that sticking to a common terminology has its advantages, especially in a complex ruleset as MtG's. As Ikegami said, there are possible alternative misinterpretations for many of them, perhaps unintentionally so, and people will not always check back with what exactly it means when you introduce them to a concept using a phrase like that. In addition, alternative phrasings will yield fewer (and/or more wrong) search results. "Damage assignment order" is the phrasing used by the comprehensive rules, and if a standalone phrase is ever used to explain the concept, it should be this one.

By the very rule you quoted (and the one directly following it):

You choose the damage assignment order of attacking creatures you control. (CR 509.2.)
Your opponent chooses the damage assignment order of blocking creatures he controls. (CR 509.3.)

Simple Example
You: "I attack with Centaur Warrior."
Opponent: "I block with Jeskai Student and Disciple of Phenax."
You: "I will assign damage to Jeskai Student first, followed by Disciple of Phenax."
You: "Damage?"
Opponent: "Sure."
Note: There was no need for your opponent to declare a damage assignment order, because each of his blockers are only blocking one attacker. Centaur is assumed to be first in line.
Centaur Warrior must deal at least lethal damage to Jeskai Student before dealing any damage to Disciple of Phenax. You are not allowed to change the order at this point. Therefore, Centaur deals all 3 points of damage to Student. Student and Disciple each deal 1 point of damage to Centaur.
Centaur and Disciple live. Student dies.
Intermediate Example
You: "I attack with Ash Zealot."
Opponent: "I block with Elvish Mystic and Runeclaw Bear."
You: "I will assign damage to Runeclaw Bear first, followed by Elvish Mystic."
You: "First Strike Damage?"
Opponent: "Sure."
You: "Bear dies. Second Strike damage?"
Opponent: "I'll cast Giant Growth on my Elvish Mystic."
You: "Ok it resolves. Second Strike damage?"
Opponent: "Sure."
Ash Zealot deals damage in the first damage phase. Zealot must deal at least lethal to Runeclaw Bear before moving on to Elvish Mystic. Therefore, Zealot deals all 2 points of damage to Runeclaw Bear.
At this point, you both get the chance to play spells and activate abilities. Your opponent takes this chance to make his Elf larger with Giant Growth. We then move to the second damage phase. Runeclaw Bear is already dead and so cannot deal damage. Ash Zealot already dealt its damage. Elvish Mystic is the only creature than will deal damage, and so it deals 3 point of damage to the Zealot.
Mystic lives. Zealot and Bear die.
Special Notes
Some abilities modify, or provide exceptions to, the rules for attacking and blocking. For a particularly complicated example, read about an old mechanic called Banding.

You said earlier that Banding deserves to be a footnote as opposed to the entire answer; I recommend adding a footnote here mentioning that Banding can change the normal rules that you describe here.

@Gendolkari I probably should have said "At best, it deserves to be a footnote." But I'll mention it anyway for completeness.

You're correct in your assumption. but the Banding rule provides an exception to this, as below.

702.21j During the combat damage step, if an attacking creature is being blocked by a creature with banding, or by both a [quality]
  creature with “bands with other [quality]” and another [quality]
  creature, the defending player (rather than the active player) chooses
  how the attacking creature’s damage is assigned. That player can
  divide that creature’s combat damage as he orshe chooses among any
  number of creatures blocking it. This is an exception to the procedure
  described in rule 510.1c.

In your example, if the 4/4 and the 1/1 were banding and blocked your 3/3, then the defending player could put the 4/4 first in the damage assignment order and thus prevent his 1/1 being dealt any damage.
(Side note: Unless you're playing with really old cards, you probably won't come across Banding)

Not sure why this was downvoted. Banding is a thing and is relevant to this question.

@Ellesedil I guess the downvote was because the answer had fundamentally false information in it: "Between choosing damage assignment order and assigning the damage, players can cast spells and activate abilities, so creatures could gain or lose the Banding ability" I've edited the answer to be a bit more specific in simply pointing out the exception that Banding creates.

@Aiken: Ah, good call. Glossed over that part as I paid attention primarily to the rule text.

@Ellesedil The downvote was mine, because the answer was (and still is) primarily about banding, which is an obscure mechanic that sees no competitive play and WotC has officially announced was a mistake to have ever printed. It's so needlessly complicated that it deserves to be a footnote instead of the entire body of the answer. At this point, all I see is the "You're correct" at the top, and the rest of the answer may as well be invisible.

@Rainbolt: All of those things about banding is irrelevant. It exists, some cards have it or can grant it, and may come up in casual play. And then there's also things like this, which none of the answers talk about and actually perfectly fits with the asker's question.

@Ellesedil Actually, my answer specifically addresses the damage assignment order of blocking creatures, and names the relevant rule associated with it.

@Aiken: Read the rules. My statement was correct. The damage assignment order is declared in the Declare Blockers Step, as mentioned by CR 509.2 and CR 509.3. Afterwards the active player receives priority according to CR 509.5. The damage is dealt in the step after that, the Combat Damage Step (CR 510). The side note you added is a good point, though.

@M.Herzkamp Ah my mistake, you're right that a creature could potentially lose Banding after blockers and damage assignment order are declared. However looking at the Banding text above it seems like the Defending Player chooses the damage assignment order and that won't change even if the blockers lose Banding, they just won't be able to divide the damage as they please when combat damage is dealt, a point that's somewhat irrelevant to the question being asked.

@Aiken: No. Banding is an explicit exception to rule 510.1c. It is stronger than just redefining the damage assignment order. If on of the blockers has banding, the defending player may arbitrarily divide the attacking creatures damage among the blocking creature. Neither blocking creature needs to take lethal damage in order for the next to take some. That's it: Banding is complicated.

@M.Herzkamp I'm aware of that, hence me saying "They just won't be able to divide the damage as they please when combat damage is dealt" (i.e. ignore 510.1c). If the blockers lose Banding after the damage assignment order has been set (by the defending player) then that player has still determined the damage assignment order instead of the active player, Which is what's relevant to this question.

@Aiken: The damage assignment order is untouched by Banding. That is still done in the Declare Blockers Step by the attacking player.

Yes, it is accurate. There is no blocking order, only damage assignment order. Since you declare how your attackers damage will be assigned to it's blockers, your opponent can't change it.


text:
How does Lava Burst work with hexproof/shroud?
How does Lava Burst work with hexproof/shroud ability?
Lava Burst text says:

If Lava Burst would deal damage to a creature, that damage can't be prevented or dealt instead to another creature or player.

However, hexproof / shroud ability also say:

This creature can't be the target of spells or abilities ...

So how does it actually work? Can Lava Burst damage a hexproof / shroud creature, or can't that creature be targeted at all?

Murgatroid99 covered the important parts, but I wanted to add the easy to remember acronym for Protection just for reference. D.E.B.T. Can't be Dealt Damage by, Enchanted by, Blocked by, or Targeted by whatever it is protected from. Hexproof literally means "Can't be the target of spells or abilities your opponent controls." As you can see, there is some partial overlap there. +1 to you for looking up some of the rules text before posting.

@Rusher, This question has nothing to do with Protection. Prevention isn't Protection. And the "E" of DEBT is really Enchanted/Equipped/Fortified by.

@ikegami I never said Prevention was Protection. Damage prevention is a component of Protection, and therefore related to the question.

@Rusher, By that logic, my company's policies are on topic since damage prevention is also a component of them. Your comment is very very very confusing.

No, Lava Burst cannot damage a creature with shroud or an opponent's creature with hexproof. An opponent's creature with hexproof or shroud can't be the target of anything you control, period. The "cannot be prevented" text only means that prevention effects do not prevent or change that damage. The relevant rules here are:

615.1. Some continuous effects are prevention effects. Like replacement effects (see rule 614), prevention effects apply continuously as events happen -- they aren't locked in ahead of time. Such effects watch for a damage event that would happen and completely or partially prevent the damage that would be dealt. They act like "shields" around whatever they're affecting.

615.11. Some effects state that damage "can't be prevented." If unpreventable damage would be dealt, any applicable prevention effects are still applied to it. Those effects won't prevent any damage, but any additional effects they have will take place. Existing damage prevention shields won't be reduced by damage that can't be prevented.

To clarify a bit, cards talking about preventing damage mean it very specifically and literally. So Lava Burst doesn't mean it's unstoppable, that you can't do anything that'd in any way avoid the damage being dealt, it just means that damage prevention effects (like protection, and things that actually say "prevent damage") won't work.

I should point out that at least in this case, protection would also mean that the spell couldn't have targeted the creature.

Ack, yes - wish I could edit to clarify that. I really just wanted to emphasize that "preventing damage" is a nice specific thing, not a fuzzy description.

Lava Burst can damage a creature with hexproof if it's your creature.

It's quite simple: Hexproof and Shroud don't prevent damage; they prevent targeting. Lava Burst cannot target something with Hexproof, something Lava Burst must do far before it tries to deal damage.

In this case does a zone effet like "Deal X to target opponent creatures" deals damages to it despite Shroud | Hexproof ?

I was speaking of effects to be applied to all creatures for example, and not just one specific. And I'm not sure, it's targetting a player, but the shroud is on the creature, not on the player

Yes but since it's targetting the player, and the shroud is on the creature it should affect it. What could be a problem here would be they player having shrould on himself.. No ?

@Alexandre Audin, I misread (in part because of the confusing reference to zone effects when the effect didn't mention any zones). The player would need shroud or hexproof to stop that effect.  This is covered by my answer: Hexproof and Shroud don't prevent damage; they prevent targeting.


text:
What happens if you ambassador a hovel?
In Dominion, what happens when you Ambassador (Seaside) a Hovel (Dark Ages)?

Nothing happens at all.
There's a (likely unofficial) rules clarification on Ambassador's Dominion Strategy wiki:

If you reveal a card which is not in the Supply, such as Spoils, Madman, Mercenary, or Shelters, Ambassador does nothing.

The same article also quotes an official FAQ clarification:

If the pile for the chosen card runs out, some players may not get one; cards are given out in turn order starting with the next player.

Since Hovels are not present in the Supply, you cannot return your hovels there. Further, nobody can gain them: since they aren't available in the Supply, they are effectively perpetually out of stock.


text:
Will my opponent lose from his own Plague Spitter enchanted with Soul Link, if the Plague Spitter deals him lethal damage?
My opponent is at 1 life. He controls a Plague Spitter and 2 other creatures (1/1 tokens). In his second main phase, he puts Soul Link on the Plague Spitter and passes the turn.
In my turn I do nothing that changes his board.
Will my opponents die in his next upkeep phase, due to the 1 damage dealt by the Plague Spitter, or will he be able to gain life from his other creatures (and me) taking damage before he takes damage?

He dies. Soul Link's ability is a triggered ability, meaning that when the Plague Spitter deals damage, the life-gaining ability is placed on the stack. Before it resolves, state based actions are checked and players get priority. During the state based action check he will be at 0 life, and lose the game.
The similar card Spirit Link has a ruling on Gatherer that supports that:

You only gain the life when the triggered ability resolves. If you are reduced to zero life before the ability resolves, you will lose before gaining the life.

If he had used Lifelink instead, the creature would have had lifelink. That changes the way damage is dealt, so that the controller of the creature gains life as simultaneous part of the damage dealing. He would have survived in that case.

But the Plague Spitters ability is also a triggered ability. Is it not possible for my opponent to decide in wich order all of the triggered abilitys go on the stack?

They don't trigger at the same time -- Plague Spitter triggers at the start of the upkeep phase, but Soul Link only triggers when Plague Spitter's damage is actually dealt. There's no way those can happen in another order.


text:
Hammer of Purphoros doesn't let me destroy my opponent's lands; why is that exactly?
The text on Hammer of Purphoros reads:

Sacrifice a land: Put a 3/3 colorless Golem enchantment artifact creature token onto the battlefield.

I know that this doesn't allow me to destroy my opponent's lands but I would like to know why. What wording would allow me to do that? "Destroy target land"?

"Sacrifice" and "Destroy" are 2 separate things, though they both result in sending a permanent to the graveyard. You can only ever sacrifice a permanent that you control:

701.14. Sacrifice

701.14a To sacrifice a permanent, its controller moves it from the battlefield directly to its owner’s graveyard. A player can’t sacrifice something that isn’t a permanent, or something that’s a permanent he or she doesn’t control. Sacrificing a permanent doesn’t destroy it, so regeneration or other effects that replace destruction can’t affect this action.

And you are correct about the second part, a card like Pillage would let you destroy an opponent's land.
"Sacrifice" happens only when an ability tells you to "sacrifice" something (or keywords whose rules require sacrificing, such as Annihilate). "Destruction" can happen either from abilities that say "destroy", or from state-based effects such as a creature having taken too much damage. Things like "Indestructible" can prevent Destruction, but not Sacrificing.

it might be worth adding a note about destruction being a state based action and clarifying that "indestructible" as an example has no bearing on sacrificing. Just incase anyone gets the idea that a Darksteel Citadel would give them unlimited golems

@Patters, Destroy is not a SBA. Destroy has noting to do with SBAs (except that some SBAs instruct you to destroy things, just like some SBAs instruct you to remove counters). Destroy is a keyword action (just like "sacrifice", "move", "cast" and "draw"). You are to perform keyword actions when instructed. Just like "sacrifice", "destroy" is simply a wrapper around "move". Having a separate word allows one of the actions to be replaced (e.g. by regeneration) or prevented (e.g. by indestructibility) without affecting the others.

you are correct, i conflated the destruction that occurs when a creature has lethal damage marked on it (the state based action) with destruction as a whole occurring as a state based action. I still feel the answer could benefit from this clarification of the distinction between sacrifice and destroy though, as the asker (and hence others) appears to not have enough experience to identify the distinction

@Patters, Rather, I think it's worth mentioning that while Hammer uses "Sacrifice..." as part of a cost, "Destroy target..." cannot be part of a cost. Costs cannot target.

Is there a rule that says that costs cannot target? I haven't seen that, though it makes sense.

@GendoIkari, I don't think anything in the rules directly or indirectly forbids targeting in costs, but it would be really weird. 1) There's no chance to response, so there would be no reason to target instead of choosing. 2) Targets are rechecked on resolution, which would make "destroy target {permanent}" particularly problematic.

@GendoIkari, You'd be far more like to see "As an additional cost, destroy a land", but that you wouldn't see that either. 1) One usually gets a check to response to something destroys (e.g. to put a regeneration shield on the permanent). 2) You could destroy a land with a regeneration shield to pay the cost. 3) A permanent is considered destroyed even if it regenerates, so "Destroy {permanent}. If you do, ..." would not be sufficient to get around the problem described in (2).

@Brian S, You won't see "Destroy a ..." as part of a cost either. See the previous comment. I did mention that in my answer, and I just fleshed out that part of the answer.

@GendoIkari, The MtG rules are permissive in nature, not restrictive. That is, they say what you can do (and you can't do anything else), rather than saying what you can't do (while allowing you to do anything else). The CR lists spells, activated abilities, and triggered abilities as possible things with targets. Costs are neither spells, activated abilities, nor triggered abilities, therefore they cannot target. A cost could destroy a permanent in theory (with wording along the lines of "destroy a..." or "choose a..."), but it would not target that permanent.

@ikegami, You're right, it's extremely unlikely we'll ever see a cost such as "Destroy a..." However, the rules permit such a construction. The rules do not (currently) permit a cost in the form of "Destroy target..."

Note: there are a small handful of exceptions to the permissive vs. restrictive setup of the rules. For example, 408.1 "[objects in the Command zone] cannot be destroyed"

@Brian S, I agree that "target" WON'T be found in costs, but you keep saying it CAN'T. I'm not sure it's correct. Could you point out which rule forbids targets in costs?

@ikegami, As I said, the rules are permissive, not restrictive. There is no rule that says you can't have targets in costs, because there doesn't need to be. The rules only allow for targets in spells, activated abilities, and triggered abilities. Since the rules don't allow for targets anywhere else, you can't have targets in costs.

@Brian S, An activated ability has the form "cost: effect". If they can't be in cost because cost is not one of spells, activated abilities or triggered abilities, then they can't be in effect either. And we both know that's not true.

@ikegami, I disagree. "cost: effect" is the rules text for an activated ability (which might include the word "target"). However, the activated ability is the object which is put onto the stack, which is what actually has a target (if any). The cost of that ability is not on the stack.

@Brian S, The cost is just as much on the stack as the effect. Which is not at all. Only the ability is on the stack. The ability has rules text, which includes a cost and an effect. Anything you say that applies to one applies to the other too.

I still disagree with your interpretation. I realize this is argument from authority, but: MTGS Global Mod/Rules Guru Kahedron, MTGS Rules Guru viperesque, Rules Adviser cyphern

Oh, and L1 Judge ryzorz. I think that's all for "costs cannot target" and "costs can't target" coming from people in a position of any kind of rules authority. (There were other results for those two searches, but the posters didn't have anything identifying them as having a position of authority of any kind.)

@Brian S, What interpretation do you disagree with? The rules are explicit about what can go on the stack, and effect is not one of them. Effect is not even an object!!! Look for yourself. You said it's not allowed if it's not in the rules, so tell me where you see that effects can be placed on the stack. All you'll find is that abilities can, and that abilities (as objects) have rules text.

@Brian S, I don't the impression that ryzorz was saying the rules prevent it. He's talking about templating, and he's saying you can't write an ability with a cost that targets. I fully agree with that.

I think it's meaningless to debate whether there is or should be an explicit justification in the rules that "target" cannot occur in a cost, because the rules are not meant to govern what can be printed on cards. The rules are to determine how cards are played.

@David Z, Templating is actually a widely discussed topic. Thousands would disagree with you. The OP's very question is about it. He's asking "what wording would be used to ...". Saying that "Destroy target land" can't/won't be find on cards is very very relevant to the OP's question; it's the very question at hand!

Note that protection DOESN'T prevent destruction. It only prevents damage (and attachment, and blocking and targeting). You can have all protections you want, you'll still die to a Wrath of God :)

What wording would allow me to do that?

Move {some land} to {a zone}[1].
Other than abilities, some keyword actions instruct you to do this, which brings us to your next question.

"Destroy target land"?

Yes, because destroy is defined as move {permanent} from the battlefield to its owner’s graveyard.
You'll never see "target" in a cost, though. There would be problems with doing that, and there would be no gain over simply choosing (e.g. "destroy a land").
That said, you'll never see "destroy" in a cost either. A cost is something you must pay; it should not be a benefit under normal circumstances. Furthermore, destruction can be nullified by regeneration. It should not be possible to avoid paying a cost in that fashion.

I know that [Sacrifice a land] doesn't allow me to destroy my opponent's lands

Sacrifice is defined as move {a permanent} you control from the battlefield to its owner’s graveyard. It would work if it wasn't limited to a permanent you control.

Note that "return" is sometimes used as a synonym for "move".


text:
Can Guttersnipe hit Planeswalkers?
Guttersnipe's ability states:

Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.

Now, Planeswalkers are classed as "Players". I found this ruling that someone's interpreted:

306.7. If noncombat damage would be dealt to a player by a source controlled by an opponent, that opponent may have that source deal that damage to a planeswalker the first player controls instead. This is a redirection effect (see rule 614.9) and is subject to the normal rules for ordering replacement effects (see rule 616). The opponent chooses whether to redirect the damage as the redirection effect is applied.

Does this mean Guttersnipe can hit a Planeswalker that opponent's controlling instead?

The footnote of this answer shows some intricacies of the player-planeswalker distinction when it comes to targeting.

As of the Dominaria rules update, no. The planeswalker redirection rule you cite has been removed, and so dealing damage to "each opponent" means literally that, just player(s), no planeswalkers involved.
It now reads:

306.7. Previously, planeswalkers were subject to a redirection effect that allowed a player to have noncombat damage that would be dealt to an opponent be dealt to a planeswalker under that opponent’s control instead. This rule has been removed and certain cards have received errata in the Oracle card reference to deal damage directly to planeswalkers.

In that spirit, many cards which said "target player" have been changed to read "target player or planeswalker", many which said "target opponent" now say "target opponent or planeswalker", and many which said "target creature or player" now say "any target".
Cards like Guttersnipe that wouldn't be so trivial to update have generally been left alone.

For posterity, the original pre-Dominaria answer follows.
Yes, you can redirect Guttersnipe's damage to a planeswalker, due to the rule you cited. (That's an actual rule, not a ruling or someone's interpretation.) Guttersnipe is dealing noncombat damage to a player, you are that player's opponent, you control the Guttersnipe, and you may therefore redirect the damage.
But saying "planeswalkers are classed as 'players'" is only going to get you into trouble. They are not players. They're, well, planeswalkers. There are a few things you can do that make them feel like players: you can redirect damage like this, and you can choose to attack them or your opponents with your creatures. But they aren't players. If a card actually says "player", it means a player, not a planeswalker.
Some examples:

A burn spell like Lightning Strike ("...deals 3 damage to target creature or player") can only target a player. You may end up redirecting the damage, effectively using it on their planeswalker, but you still have to target your opponent. If they have a Witchbane Orb ("You have hexproof"), you can't target them, so you can't cast the spell in the first place.
Gray Merchant of Asphodel ("...each opponent loses X life...") doesn't do anything to your opponents' planeswalkers - you can't redirect loss of life. Similarly, you can't somehow use life gain on a planeswalker.
Dreadbore ("Destroy target creature or planeswalker.") doesn't do anything to players.

Most of the time things are pretty obvious anyway - for example you're not too likely to think a planeswalker can draw cards and try to use Opportunity on it. But you can avoid the chance of confusion by just remembering what you can do (attack and redirect damage) rather than thinking of planeswalkers as players.

@ikegami I am still not seeing it, all I said was that as the redirect happens you can still pick the planeswalker to take the damage. And without sufficient knowledge of rule 306.7, the last sentence basically amounts to you can never damage a planeswalker with a card that sais target player.

Re "without sufficient knowledge of rule 306.7", you mean if you ignore the first half of the answer?

I'm not sure what the comment discussion here was about, but I tried to add some of the more common player vs planeswalker things that might come up, in case the "player means player" part was confusing.

@Lyrion Yes, without knowing the rule that you can redirect noncombat damage from a player to a planeswalker, you won't know that you can use a card that deals noncombat damage to a target player (but not a planeswalker), and redirect that damage to a planeswalker.

Is there a good way to deprecate this answer with the new rule changes?  I'm not sure an edit would actually work for this answer.

@ryanyuyu I'm not very familiar with the norms for this site; would editing this answer to include a notice that it is out-of-date be seen as helpful or as vandalism?

Just leave a comment here for @Cascabel and she should come by and fix it at some point.

Even an edit would've been helpful, but  it's nice to actually update rather than mark as out of date, so I went ahead and did that.

With the release of the Dominaria set, the answer to this question has changed: https://magic.wizards.com/en/articles/archive/news/dominaria-oracle-changes-2018-04-13
There is no more "planeswalker damage redirection"; spells and abilities must now either specify planeswalkers specifically (as on this Scuttling Doom engine) or specify "any target" (as on this Shrapnel Blast).

Here is the current oracle text for Guttersnipe's ability:

Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.

Since this ability does not reference planeswalkers specifically and does not call for "any target", you can no longer deal damage to a planeswalker with Guttersnipe's ability.

My answer is no, I know as does everyone who plays magic enough that the ruling changes between a target (singular) and each/all opponents (plural) you find this a lot in hexproof cause it states: you/creature with hexproof can't be "the" target of spells and effects but if the effect targets opponents as in multiple/any hexproof pretty much goes numb. This being said the rules state a player not multiple and the card effect states each as in multiple therefore the ruling would have no effect on how you want to use it. A suggestion though, find a section on how multiple opponent targets would work with Planeswalkers and reply. I would like to see it turn out the way I think it might where the way this article was phrased didn't.

Welcome to the site. I would recommend that you include some relevant rules citations supporting your position, "I know, and as does everyone who plays magic enough" isn't really great supporting evidence. Your point that Guttersnipe can't Target a Planeswalker is correct, but the OP seems to be asking if Guttersnipe's ability can be redirected to a Planeswalker; which is slightly but significantly different.

Ruling 306.7 doesn't say anything about targets.  All it says is that damage that will be dealt to a player can be redirected to a planeswalker.  Whether the damage comes from a source that targets a single player or affects all opponents is irrelevant.

@BJMyers don't forget the distinction between combat and noncombat damage, with the old 306.7 it specified only noncombat damage could redirect that way, combat was declared directly at the player or walker.

The correct answer is yes. Any spell that can target a player, can also target a planeswalker.
Source - http://magic.wizards.com/en/game-info/planeswalker-cards

If a spell or ability you control would deal damage to an opponent, you may have it deal that damage to a Planeswalker that opponent controls instead. So while you can't target a Planeswalker with a Shock, you can have a Shock that targets your opponent deal 2 damage to one of his or her Planeswalkers instead of to the player.

You are mostly correct, but saying "can target a planeswalker" is both misleading and very wrong. All though you clarify after that what you mean, the fact still remains that it can NOT target a planeswalker, and that distinction matters for various things.

This answer is no longer current, and it is not correct (and never was). The planeswalker redirection rule being cited here has been removed from the game rules as of Dominaria. The new rules and corresponding errata mean a lot of old spells that once only targeted players now also target planeswalkers, but there are many spells old and new which target only players and never planeswalkers.


text:
Manland and Sentinel of the Eternal Watch
Sentinel of the Eternal Watch says, "At the beginning of combat on each opponent's turn, tap target creature that player controls."
Can the opponent activate a manland after this ability and attack with it to prevent getting the manland tapped?

Yes, you can get around the Sentinel this way with a manland. I'll assume you have the Sentinel, and your opponent has an untapped Mutavault.
At the the Beginning of Combat step in the Combat phase, all abilities that trigger at that point go on the stack. As part of putting the abilities on the stack, you have to choose a target, and that target must be a creature at that point per the ability text. So, by the time that ability's on the stack, the target is set, and can't be changed — and it isn't the manland.
Then, the active player, and the non-active player, will each get priority at least once. Your opponent can activate their Mutavault's abilty while the triggered ability is still on the stack, or they can let that triggered ability resolve and then activate their Mutavault. (The latter is probably safer, in case you have something like Redirect, such as the standard-legal Insidious Will.)
Then we move on to Declare Attackers, and their Mutavault is a Creature at this point, not tapped, and able to attack.

Yes, your opponent can do that.
The Combat Phase consists of 5 steps: Beginning of Combat, Declare Attackers, Declare Blockers, Damage, and End of Combat. Entering each step causes certain abilities to trigger and those abilities will go on the stack before anyone has priority to make plays. Sentinel of the Eternal Watch's ability will trigger during Beginning of Combat, then the active player (the player whose turn it is) will gain priority and try to respond to that ability while it's on the stack, followed by the non-active player. If each player passes priority, the ability will resolve.
After the ability resolves, priority will go back to the active player, then non-active player if the active player passes priority to make a play. During this period in Beginning of Combat is the latest possible time that a player with a manland could activate its ability to become a creature that could participate in being declared an attacker. During the Declare Attackers step, attackers must be declared immediately, then players will receive priority after that.


text:
What happens when I redirect multiple large sources of damage through the en-Kor ability to Mogg Maniac?
The situation is this:
I control a Shaman en-Kor and a Nomads en-Kor and a Mogg Maniac. During my opponent's turn, I cast Inferno, dealing 6 damage to all creatures and all players.
Is it possible for me to redirect the 6 damage done to the shaman and the Nomads to the Mogg Maniac AND have the Mogg deal a total of 18 damage to my opponent before the Mogg Maniac dies?
or...
Will the Inferno kill the Maniac before I can redirect any damage to it from my en-Kor creatures?
I'm confused about the timing of this combo since the shamans and the nomads en-Kor ability is an activated ability that allows me to redirect 1 damage for 0 mana.
Can someone help me understand this?  (Is the combo even possible?)

Rulings on gatherer for both Shamen en-kor and Nomads en-kor state: "It is possible to redirect more damage to a creature than that creature's toughness." so my guess is yes, this is possible.

Mogg will deal 18 damage, but it will deal it after dying.

The en-Kor's redirection only works if you activate it before they take damage. When you activate their redirection ability, it creates a shield that will redirect the next point of damage it would take.
The redirection shield is a replacement effect. It causes Inferno to deal damage to Mogg instead of the en-Kor. Inferno still deals all of its damage simultaneously.
This is how the game progresses:

You cast Inferno (and retain priority).
Six times,

You activate Shaman en-Kor's first ability targeting Mogg.
Shaman en-Kor's first ability resolves, creating a shield that will redirect damage later.

Six times,

You activate Nomads en-Kor's ability targeting Mogg.
Nomads en-Kor's ability resolves, creating a shield that will redirect damage later.

Inferno resolves.

It will simultaneously deal 18 damage to Mogg and 6 damage to each player. Simultaneously, life is subtracted from players' totals, damage is marked on Mogg and Mogg's ability triggers.

State-based actions are performed simultaneously.

Any player with non-positive life lose the game. (I'm going to assume noone loses here.)
Mogg is destroyed for having marked damage exceeding its toughness.

Mogg is put in the graveyard from the battlefield.

Mogg's triggered ability is placed on the stack targeting your opponent.
Mogg's triggered ability resolves.

It deals 18 damage to the targeted opponent.

Note that Mogg only takes damage once in this scenario (even though some of it was originally intended for the en-Kor), so its ability only triggers once for the entire 18 damage.

So if I attacked my opponent in my turn with both the en-Kor creatures and the Maniac, and they all got blocked, I could still play the Inferno and direct both the eventual combat damage from the blocking creatures AND the damage from the Inferno to the Maniac?

No. That would be like trying to do more damage to Mogg after step 7 in the above. The damage from the Inferno will kill the Mogg long before combat damage is dealt. Mogg won't be around to receive (redirected) combat damage.

Okay, I kind of expected that. But if Mogg had Indestructible, and I used the shamans ability "to redirect damage from another creature to himself" on my opponents creatures and redirected that damage to Mogg too, then Mogg (and my opponents creatures) would be around to deal and recieve combat damage too right?

Right. Indestructible creatures still take damage as normal. SBAs (in step 5) just won't destroy it. So yeah, dealing more damage to it after step 7 is perfectly fine.

Yes, you can do this. All damage will be done simultaneously; you would need to activate each en-Kor's ability 6 times before the Inferno resolves. When you do, Mogg Maniac will take 18 damage. The toughness of the Mogg Maniac is not relevant here; it is taking 18 damage.

119.5. Damage dealt to a creature or planeswalker doesn't destroy it. Likewise, the source of that damage doesn't destroy it. Rather, state-based actions may destroy a creature or planeswalker, or otherwise put it into its owner's graveyard, due to the results of the damage dealt to that permanent. See rule 704.


text:
Could Cemetery Puca copy a Primordial Hydra?
If I kill my opponents 4/4 Primordial Hydra, will I be able to use my Cemetery Puca's activated ability on the Hydra, and have it become a 4/4 Primordial Hydra, or will my Puca die because the Hydra is considered a 0/0 creature when it is put into the graveyard, due to the X part of its mana cost?

Your initial thought is correct. It will get copied, become a 0/0 creature, and die (unless you have a way to save it through a static effect, like Anthem or Caged Sun).
Relevant rules:

706.2. When copying an object, the copy acquires the copiable values of the original object's characteristics ... 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 "as . . . enters the battlefield" and "as . . . is turned face up" abilities that set characteristics, and by abilities that caused the object to be face down. Other effects (including type-changing and text-changing effects), status, and counters are not copied.

So your Puca does have the "~ enters the battlefield with X counters", but that's irrelevant because it's not entering the battlefield anyway. The object already exists, it's just getting a facelift. (The X would be 0, but that doesn't matter because it isn't triggering.) As for the existing counters, the final clause states that counters are not copied. So you basically get to kill your own Puca by doing this. Which I suppose isn't so bad if you have a Blood Artist or something. =)

Just realized how awkward it would be if you had actually chosen green for your caged sun in a blue-black control deck... but ya know, I'm not judging!

A more likely reason you'd actually want to copy the hydra is if you have a way to give it counters; any counters and enchantments placed on the Puca persist even if it copies something, after all.

So if I understand this right I wouldn't even be able to make a token, that is a copy of the Primordial Hydra? It would become a 0/0 token right?

"I wouldn't even be able to make a token, that is a copy of the Primordial Hydra?" You can make a token copy of the Hydra, but it will enter the battlefield as a 0/0 and quickly die. This might seem impractical, but it may be useful if you want to draw a card with Fecundity or something.

@Kevin you are not correct. if you would make a token that is a copy of the Hydra (for example with Spitting Image), it will enter the battlefield and therefore get it's counters.

@IvoBeckers, I agree that the "Primordial Hydra enters the battlefield with X +1/+1 counters on it" ability will apply, but X will be zero when it does. "The amount of mana I spent for X when I originally cast this creature" is not a copiable value.

@Kevin ah yes you're right. somehow I was thinking it was Kalonian Hydra that has four instead of X

@Kevin, I disagree with that - in this case, the "new" hydra never enters the battlefield. The Puca is already on the battlefield, and is merely changing its characteristics. So it will gain the "enters the battlefield" ability, but it will never trigger. I agree with your statement if it were cloned with Clone or Vesuvan Doppelganger's enter the battlefield trigger. (Obviously Doppelganger's triggered ability has the same pitfall Puca does.)


text:
Can I use Plaxcaster Frogling to temporarily shut off Species Gorger's ability?
I'm currently working on a deck which is built around Species Gorger and its ability to return creatures I control to my hand. In order to make my deck work as intended, I need a way to "turn off" or avoid SG's ability from time to time. I was wondering if Plaxcaster Frogling could do the job. For the record, SG's ability reads:

At the beginning of your upkeep, return a creature you control to its owner's hand.

Let's say I control a Species Gorger and a Plaxcaster Frogling. The Gorger has a +1/+1 counter on it. At the beginning of my upkeep, I have to return a creature I control to my hand. If I choose the Gorger to be returned, and use the Plaxcaster's activated ability to make sure the Gorger doesn't leave the battlefield:

Will the Gorgers triggered ability be neutralized? or,
Will the Gorger just look for another creature to send to my hand, since I have chosen an invalid creature to send to my hand in the first place? After all, it says return a creature you control to your hand.

Since it dosn't say target creature, I'm not sure if the Plaxcaster would have to use its ability on all creatures on my battlefield, that I don't want to return to my hand, or if it is enough to "protect" the one creature that was originally chosen for the Gorger to send to my hand?

Only way to stop the ability is by skipping the upkeep (e.g. Eon Hub) or counter it (e.g. Stifle, Trickbind, Voidslime)

Hmm okay. Is there a creature or enchantment that can counter triggered abilities?

Sundial of the Infinite is about the only repeatable way to do this on one card (when you end your turn, the stack is cleared), though you'll obviously skip your draw, main, and combat phases, too. If you're clever, you might find some combination of cards to make use of phasing or face-down or "loses all abilities" effects. But if you're trying to avoid bouncing a creature, you're not playing Species Gorger properly. Run Wall of Blossom / Elvish Visionary.

Oh no obviously I want to use the Gorgers ability to bounce my creatures. Just not all the time! I'm considering playing "vanishing" on the gorger, but it's not ideal!

Vanishing doesn't help (by itself), because phasing occurs during the untap step, and players don't get priority until upkeep step after triggers have been put on the stack. (If you phase out during previous end step, it comes back in and triggers, if you phase out during upkeep, the trigger is already on the stack.)

Hmm okay. So maybe this is a far fetched solution, but if I had an Eon Hub on the battlefield and used Capsize at the beginning of my upkeep on the Eon Hub, I would be able to control the Gorgers Bouncing effect right? Since Capsize would be put on the stack too, and I could choose to place it on the stack before the Gorgers ability.

Species Gorger's triggered ability does not target. Abilities that target use the word "target". As such, it does not interact with Plaxcaster Frogling's activated ability or any other shroud effects.
In addition, because the triggered ability does not target, you make the choice of which creature to return while the ability is resolving (which means the choice can't be responded to in any way).