Humble God

Assume that there's a Humility on the battlefield, and you control Heliod, God of the Sun. Question: Will Heliod be indestructible? But more interestingly: Will your other creatures have vigilance?

(Note that the Oracle text of Humility is: "All creatures lose all abilities and are 1/1." Humility doesn't make anything a creature, nor does it remove any types.)

There are four possible combinations here depending on which one entered the battlefield first, and whether your devotion to white is less than five or not.

The first question depends solely on your devotion to white. If it's less than five, the question is whether Humility removes the ability that makes Heliod a non-creature or not. Since Humility only affects creatures, and Heliod's ability may make it a non-creature, this might at first seem like a chicken-and-egg problem. (If Humility removes the ability, then there's nothing to make it a non-creature, but if the ability makes it a non-creature, then Humility won't affect Heliod.)

However, the seeming problem is resolved thanks to the layering system. Heliod's ability is evaluated in layer 4 (the layer where type setting and removing abilities are evaluated). This happens before evaluating Humility's ability, which is done in layer 6 (the layer where ability adding and removing is evaluated.) Thus Heliod's ability trumps Humility's, and thus if your devotion to white is less than five, Heliod won't be a creature, Humility won't affect it, and it will be indestructible. If your devotion to white is five or more, then Heliod will be a creature and Humility will remove all of its abilities and make it 1/1.

The more complex question is whether your other creatures will have vigilance.

If your devotion to white is less than five, and thus Heliod is not a creature, then it depends on timestamps. This is because there are now two effects that add or remove abilities (and thus are in the same layer.) If Heliod entered before Humility, then your other creatures won't have vigilance, but if Heliod entered after, they will.

Something more complicated happens if your devotion to white is five or more, and thus Heliod is a creature. This is because now the two abilities are dependent: They exist on the same layer, and the existence of one depends on the other. Thus in this case Humility's effect is evaluated first regardless of timestamps, and thus no creatures will have vigilance.

Drawing while casting

There's a lesser-known rule in Magic the Gathering that says:

401.5 If a spell or ability causes a card to be drawn while another spell is being cast, the drawn card is kept face down until that spell becomes cast (see rule 601.2h). While face down, it’s considered to have no characteristics. The same is true with relation to another ability being activated. If an effect allows or instructs a player to reveal the card as it’s being drawn, it’s revealed after the spell becomes cast or the ability becomes activated.

What this means is that if a card is drawn during the process of casting a spell (the process of casting a spell starts by the player revealing the card he or she is going to cast, and ends with its costs having been successfully paid, and involves calculating said costs in between), the drawn card is kept face down and considered to have no characteristics until the spell has been fully cast.

This rule doesn't come into play very often. To my knowledge there currently exists one single card in the entire game where this rule applies (and if I'm not mistaken, this rule was in fact added precisely because of this single card). The card in question is Chromatic Sphere.

Because the ability in Chromatic Sphere is a mana ability (it does not target and it adds mana to the player's mana pool) it can be activated when paying the cost of a spell, ie. during the casting process of said spell.

What the rule is thus saying is that if you activate Chromatic Sphere while casting a spell, the drawn card will be kept face down and considered to have no characteristics until the spell has been successfully cast (ie. it enters the stack.)

Now, an interesting question is: What happens if, for example, the drawn card is now discarded, still during the casting process of the spell? What if the drawn (and then discarded) card is, for example, Progenitus?

So, consider this situation: You start casting a spell. When it comes time to pay its mana cost, you activate the Chromatic Sphere, drawing a card (which in this case happens to be a Progenitus). You then activate the ability of a Bog Witch and discard the card you just drew. The question is: Will Progenitus be shuffled into the library or not?

The Progenitus card will be face down and without characteristics during this whole process (because the abilities of both the Chromatic Sphere and the Bog Witch are mana abilities, and activated here during the casting process of a spell). Since the discarded card has no characteristics, will its replacement effect happen?

(Note that the "reveal Progenitus" part doesn't exist any more than the replacement effect itself, if the card has no characteristics, so it can't be used as an argument for the replacement effect applying.)

The jury is still out on this one. It seems that this is an unclear situation, ie. a situation where the rules may not give an unambiguous answer. Some arguments can be made for the replacement effect happening, and other arguments for it not happening. The rules don't seem to give a definitive answer.

(In a tournament setting this would in practice be up to the judge to decide.)

Nylea, Blind Obedience

Assume your opponent controls Blind Obedience, your devotion to green is four, and you play Nylea, God of the Hunt. Question: Will it enter the battlefield tapped or not?

Nylea is a creature spell on the stack. (Well, technically speaking an enchantment creature spell, but that's not important here.) Its ability that makes it not be a creature if your devotion to green is too low doesn't come into effect until it's on the battlefield.

In fact, if we look at the whole process of the spell resolving, there isn't a single moment where the effect kicks in and it stops being a creature: As soon as it hits the table, your devotion to green will be five, and thus the ability does nothing. There isn't even a single moment where Nylea isn't a creature.

Because of all the above, the intuition would be that it enters the battlefield tapped. However, that's not so. (Many players will have the intuition that it enters untapped and, while this is the correct answer, might not know the exact reason.)

This is once again a question of how an "enters-the-battlefield replacement effect" works for a resolving permanent spell. What's happening here is this:

As the Nylea spell starts resolving, it will look if any ETB replacement effects will affect it. In this case there's one such effect that may potentially affect it: That of Blind Obedience. Said effect affects artifacts and creatures, and thus what we are looking for is the question: "Is this an artifact or creature when it hits the board?" If the answer is yes, then Blind Obedience's replacement effect will take place, else it won't.

So we "look forward in time" to see how Nylea would look on the battlefield (to see if it's an artifact or a creature there.) There are certain things that are taken into account when doing this. One of those things are abilities on the card that affect the permanent itself (rather than an ability that affects a group of permanents with certain characteristics), and Nylea has such an ability: "As long as your devotion to green is less than five, Nylea isn't a creature."

In other words, we look if Nylea would be a creature on the current battlefield, taking into account that ability. And the answer is: No, it wouldn't be a creature. And the reason for this is that your devotion to green at this moment is four, and thus the ability stops it from being a creature.

This is quite a curious situation. "Devotion" only looks for permanents that are already on the battlefield. It doesn't see this "hypothetical permanent" that we are handling here (for the purposes of determining whether it's a creature or not.) Nylea isn't on the battlefield yet, and thus doesn't change your devotion to green.

Thus the full chain of events is: The Nylea spell starts resolving, we "look forward in time" to see how it would look like on the battlefield, we see that it wouldn't be a creature (because your devotion to green is four), thus Blind Obedience does not affect it, and then it finishes resolving and enters the battlefield untapped as a creature (because now your devotion to green is five.)

"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.)