"Game state" in Magic

One easily gets the impression that the Comprehensive Rules of Magic: The Gathering read like a legal document that defines the game with mathematical precision, to the utmost detail. However, this isn't always so.

One particular example is the concept of "game state". This term is used many times in the rules but, quite surprisingly, is not defined anywhere, not even vaguely or in passing. The exact definition of the concept can become important especially when the rules talk about "the same game state" (ie. when the "game state" is the "same" before and after an event.)

Practical example: Assume that it's your turn and you have a combo that allows you to increase the power of a creature without limit, and your opponent has a combo that allows them gaining an unlimited amount of life. If you say "I increase the power of my creature by a million", your opponent may respond to it with "I gain two million life". Are you then allowed to further increase the power of your creature (thus allowing your opponent to further increase their life total and so on, potentially ad infinitum)?

The answer is no: You can't repeat this process forever. The following rule forbids it from being continued:

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.

This means that you cannot further increase the power of your creature (at least not without doing something else first.) Note, however, the bolded part.

Surprisingly, the concept "the same game state" is not explicitly defined anywhere in the rules.

It cannot mean "the game state is identical" because in this particular example it's not: The power of a creature has changed, as well as the life total of a player. Clearly something has changed, and thus the game state is not identical to what it was before. However, officially this rule still applies to this situation (and thus you are not allowed to repeat the combo before doing something else first.)

So what does "the same game state" mean? It's undefined by the rules, and therefore up to a judge to decide. One can come up with an intuitive definition (ie. something that the people who wrote that rule probably had in mind), but this is nevertheless up to a judge to decide.

Phasing out equipment

Assume that you control a token creature that has been equipped with an equipment (for the sake of simplicity, let's say for example Flayer Husk is equipped to the token it creates). Then someone casts Reality Ripple targeting the token creature. What happens?

The token creature will be phased out. What happens to the equipment? The following rule specifies what happens:

702.25f When a permanent phases out, any Auras, Equipment, or Fortifications attached to that permanent phase out at the same time. This alternate way of phasing out is known as phasing out "indirectly." An Aura, Equipment, or Fortification that phased out indirectly won’t phase in by itself, but instead phases in along with the permanent it’s attached to.

The equipment phases out alongside the creature. Because it phased out "indirectly", it won't phase in automatically during the player's next untap step.

But what happens to the token when it phases out?

702.25k Phased-out tokens cease to exist as a state-based action. See rule 704.5d.

In other words, both the token and the equipment will phase out, then the token will immediately cease to exist, and... the equipment will never phase in again, because it was phased out indirectly.

The equipment will remain phased out for the rest of the game (unless something specifically phases it in.) A phased-out permanent is treated as though it doesn't exist at all.

This is even more of a "remove from the game" than exiling is...

Swirl the Mists

Swirl the Mists is an enchantment that says:

As Swirl the Mists enters the battlefield, choose a color word.

All instances of color words in the text of spells and permanents are changed to the chosen color word.

Assume that a player has cast it earlier, choosing white as the color. Then you cast Ulasht, the Hate Seed, which says:

Ulasht, the Hate Seed enters the battlefield with a +1/+1 counter on it for each other red creature you control and a +1/+1 counter on it for each other green creature you control.

Will it look for red and green creatures you control, or white creatures you control?

Ulasht will have the color words in its text box replaced with "white" when it's a spell on the stack, and also when it becomes a permanent on the battlefield. There isn't a single moment, not even for a brief moment, that the color words are reverted back during the resolution of the spell. They are changed to "white" and remain so all the way, without ever reverting back.

This would seem to give a pretty easy answer to the question: It will look for white creatures you control when it's entering the battlefield?

Well, no. That's the incorrect answer. It will look for red and green creatures, as the original text says.

This is one of the most unintuitive, obscure and quirky aspects of the rules of the game. It's so quirky, in fact, that one could justly argue that it's an outright oversight (albeit probably one that would be difficult to fix without breaking something else.)

The thing is, Ulasht's first ability is an ETB replacement effect, and such replacement effects look "forward in time" to see how the permanent would look like when it's on the battlefield (before it actually happens). There's a specific list of things that are taken into account when looking at this hypothetical future permanent, and it so happens that Swirl's static ability is among some of the things that are not included in the list.

This means that the ETB replacement effect will look at how the permanent would look on the battlefield without Swirl's static effect, as if it didn't exist at all. In other words, the hypothetical future permanent will look unmodified, and thus the replacement effect will look for red and green creatures (even though the actual spell, and the permanent it becomes, at no point reverts back to its original wording.)


Edit (Oct 2017): New rules changes with the Ixalan set have changed this. After this rules change Ulasht will look at creature of the color specified by Swirl the Mists. It will get two +1/+1 counters for each creature of that color.

Face-down permanents and copying

Assume that you cast a morph card face down, let's say for example Willbender, and then it becomes a copy of something else, like a Llanowar Elves (eg. via someone casting Mirrorweave targeting the elves.) What happens to the face-down Willbender?

Normally a face-down permanent is a 2/2 creature with no name, color or any other characteristics. So what happens if an effect makes it a copy of something else?

Quite many players, even very experience ones, will intuitively say that it simply becomes a copy of that something else (ie. in this case it will become an exact copy of Llanowar Elves, ie. a 1/1 green creature with that name, and with its ability.) Their intuition will usually be less sure about the question of what happens to its original morph ability, and whether it can be morphed or not. Some will guess that it retains its morph ability and can be morphed, but once morphed it will still be a copy of Llanowar elves.

Of course it's not that simple, and the situation is a bit more curious.

What actually happens is that it's the down-facing side (ie. the front of the card) of the permanent that becomes a copy of Llanowar Elves, not the up-facing side. The permanent will still be a 2/2 creature with no other characteristics even though it's now a copy of Llanowar Elves.

Since the down-facing side has no morphing ability now, it can't be morphed (for as long as it remains a copy of Llanowar Elves.) If Mirrorweave had instead targeted some other creature with a morph ability, then you could morph your face-down creature using the morph cost of that other card (if you can pay it.) However, when it turns face up, it will still be a copy of that other card.

The face-down permanent could even become a copy of a non-creature (for example if Mirrorweave had targeted an animated land.) While the down-facing side would become a copy of that non-creature card, it would still be a 2/2 creature with no other characteristics.

The reason for this is that being "face down" is a state of the permanent in the exact same way as being tapped or phased out. Being in the "face-down state" implicitly means that the permanent is a 2/2 creature with no other characteristics (regardless of what the actual card is.) It would work even if a permanent, like a land, would somehow become turned face down by some effect: It would become a 2/2 creature regardless of what it originally was.

However, note that copying in the other direction is special. In other words, if Mirrorweave had targeted the face-down permanent, then every other creature would have become a 2/2 creature with no other characteristics (rather than a copy of Willbender.) This is because the rules of the game specifically define the mechanic to work like that. (More exactly, the rules state that the visible characteristics of the face-down permanent, ie. "2/2 creature" become its copyable values.)

Mana abilities and Caged Sun

I discussed in my previous blog post when abilities are so-called mana abilities and when they are not, and how this can in some rare circumstances make a difference. Here is a rather unique problem related to this topic:

Is the triggered ability of Caged Sun a mana ability or not?

To understand this question we need to first fully understand what a "triggered mana ability" is. This is defined by the following rule in the Comprehensive Rules:

605.1b A triggered ability without a target that triggers from activating a mana ability and could put mana into a player's mana pool when it resolves is a mana ability.

The following rule makes it clear when a triggered ability is not a mana ability:

605.5a An ability with a target is not a mana ability, even if it could put mana into a player's mana pool when it resolves. The same is true for a triggered ability that could produce mana but triggers from an event other than activating a mana ability, or a triggered ability that triggers from activating a mana ability but couldn't produce mana. These follow the normal rules for activated or triggered abilities, as appropriate.

So, in summary, a triggered ability is a mana ability if it produces mana, does not target, and it triggers from activating a mana ability. If the ability targets, or it triggers from a non-mana ability, then it's not a mana ability even if it produces mana.

(A relevant difference between the two types of abilities is that a mana ability does not use the stack, and instead it resolves immediately when it triggers. It cannot be responded to. A non-mana ability uses the stack and can be responded to.)

So the question is: Is the ability of Caged Sun a mana ability or not? (Does it use the stack? Can it be responded to?) The ability in question reads:

Whenever a land's ability adds one or more mana of the chosen color to your mana pool, add one additional mana of that color to your mana pool.

Normally a mana-producing ability of any land is a mana ability, so it fulfills all the requirements for the ability of Caged Sun to be a mana ability.

However, the million dollar question is: What happens if a land has a non-mana ability that produces mana?

There exist currently no land cards that have such abilities. However, it's possible to create this kind of situation via gameplay. (One possibility is to, for example, make Deathrite Shaman into a land while retaining all of its abilities. This is possible by using certain combinations of cards.)

Technically speaking if a non-mana ability of a land produces mana like this, the ability of Caged Sun will trigger and it will not be a mana ability in this case according to the strict interpretation of the rules (and thus will use the stack.) In other words, whether the ability of Caged Sun is a mana ability or not depends on what's triggering it.

This is, as far as I know, not the intent of the card, or the game's rules in general. An ability ought to always be either a mana ability or not, rather than switching between the two depending on the situation. In other words, it ought to be a fixed characteristic of the ability that doesn't depend on anything else.

Probably for this reason the official ruling by WotC is that the ability of Caged Sun is always a mana ability, regardless of the situation (at least as of writing this post.) The interesting thing is that the comprehensive rules do not support this interpretation.

As of writing this post there is no disambiguating rule in the comprehensive rules to settle this question, but many people predict that it might be added there in the future.

When mana abilities make a difference

You control a Deathrite Shaman and another creature, all your lands are tapped, but there's a land in a graveyard. Your opponent controls a Sphere of Safety (and no other enchantments.) Question: Can you attack?

If your answer was "of course, just pay the required mana cost with the Shaman", then you haven't been reading this blog enough. Naturally the correct answer is "no", but the interesting part is the reason why not.

Deathrite Shaman's first ability is not a so-called mana ability because it targets. This is defined in the rules of the game as follows:

605.1a An activated ability is a mana ability if it meets three criteria: it doesn't have a target, it could put mana into a player's mana pool when it resolves, and it's not a loyalty ability.

Since it's not a mana ability, this means that it can only be activated any time you could cast an instant, in other words, any time you have priority. The difference with a mana ability is that the latter can be used any time you have priority and whenever something requires a mana cost to be paid. (Also, mana abilities do not use the stack, while normal activated abilities do.) In the vast majority of cases this is inconsequential, but in this particular case it makes a big difference.

The cost imposed by Sphere of Safety has to be paid when declaring attackers. This is done at the beginning of the declare attackers step. No players get priority at the beginning of that step until all attackers have been declared. (Paying possible costs is part of the process of declaring attackers, as specified by the rules.) This means that only mana abilities can be used to pay the cost. Instant-speed abilities cannot.

Activating Shaman's ability in the previous step (ie. the beginning of combat step) does not help because mana pools empty between steps.

Another question: Suppose you control a creature and one untapped land that's enchanted with a Verdant Haven. Your opponent controls a Sphere of Safety and another enchantment (thus requiring you to pay 2 mana to attack with the creature.) Can you attack?

This is another interesting question because this is not an activated ability but a triggered one. Does the same principle apply to triggered abilities that does to activated abilities?

The answer is yes: A triggered ability that adds mana to your mana pool and doesn't target is also a mana ability and thus does not use the stack and will immediately add the mana whenever it triggers. Thus you can attack.

To attack, or not to attack, part 2

In a previous blog post I asked a question about what happens when a Jackal Familiar is enchanted with Furor of the Bitten. This is a similar question, but with a slightly different twist:

Assume that a Master of Cruelties is enchanted by Furor of the Bitten. What happens?

This is closely related to the other situation, but the difference is now that rather than the creature being unable to attack alone, this one can only attack alone. Thus the question becomes: Can you attack with another creature, or are you forced to attack with Master of Cruelties each turn (if it's otherwise able), precluding any other creature from attacking?

This is once again a situation where many players, even very experienced ones, get it wrong (and may cause a considerable amount of disagreement.) The correct answer is that yes, Master of Cruelties must attack each turn (if there's nothing else stopping it, eg. summoning sickness) and thus nothing else can attack.

Rule 508.1d of the Comprehensive Rules (which I quoted in the other blog post) deals with this situation. It basically amounts to:

When declaring attackers:

1. Restrictions must not be disobeyed.
2. The amount of requirements being obeyed must be maximized (without disobeying any restriction.)
3. Any other declaration of attackers is illegal.

In this particular case a declaration of attackers where Master of Cruelties is attacking obeys more requirements (without disobeying any restrictions) than a declaration where it's not attacking. Therefore it's the only legal declaration.

(Sometimes it may happen that there are several possible declarations that obey the same number of requirements. In this case the player can freely choose between one of them. However, as stated, those are the only legal ones, and one of them must be chosen.)

But wait, there is more. Here's an even more complicated twist to the problem:

Suppose you control Master of Cruelties (not enchanted by anything) and some other creatures, and your opponent casts Aggravate. What happens?

The key to resolve this situation is to realize that an effect that says "each creature attacks if able" is placing a requirement on each such creature individually, and the amount of requirements being obeyed must be maximized.

This means that if you control two creatures (one of them being Master of Cruelties), then you can choose which one attacks. (This is an example where two different declarations of attackers obeys the same amount of requirements, and thus you can choose one of them.)

However, if you control more than two creatures, then the only legal declaration is one where all the other creatures except Master of Cruelties attack (because this declaration obeys the most requirements.)

(Bonus question: What happens in the above situation if Master of Cruelties is enchanted with Furor of the Bitten?)