How exactly does Xenograft work, and not work?

Question

The Blue Enchantment Xenograft (New Phyrexia) reads like this:

As Xenograft enters the battlefield, choose a creature type.

Each creature you control is the chosen type in addition to its other types.

Discussion on The Gatherer about this card is avid, complicated, and at times, contradictory. What exactly does this card do? I was first under the impression that it affects all creature cards I control from the point it hits the board and continues to do so for the rest of the game. Then I was under the impression it only affected creatures that were in play at the time of its casting, and NOT creatures that come out later. Now I'm just totally confused and unsure about anything other than that I can obviously add creature types to some or all of my creatures, at some point or another.

Too much confusion. Someone set me straight! Specifically:

1. Does Xenograft apply to creatures that are already on the battlefield when it's cast?
2. Does Xenograft apply to creatures that enter the battlefield after it's been cast?
3. The Gatherer's details page says, among other things, this about Xenograft:

Creature cards not on the battlefield and creature spells are not affected.

What does creature spells are not affected mean exactly? Aren't all creatures creature spells? I'm lost here.

Please go the extra mile if possible and cover anything I haven't mentioned here if it comes to your mind. I'm so lost with this card that I wouldn't be surprised if you end up answering questions I have that I can't even put into words yet.

Answer 1

All creatures already on the battlefield and all creatures that come under your control later are affected by Xenograft. No if's and but's. As pointed out, it's a static ability that generates a continuous effect. If Xenograft would affect only the creatures that are in play at the time of its casting, the wording would be quite different and would probably involve counters to mark the affected creatures.

Creature cards not on the battlefield are simply that: Creature cards on the stack, in your hand, library, graveyard, command zone, exile, ante, or out of game are not affected by Xenograft.

Creature spells are not creatures, but objects on the stack. You control the spell, but a spell is not a creature, so Xenograft does not apply to them either. Only if and when the spell resolves does it become a creature to which Xenograft can apply.

Creature spells are spells, not creatures:

111 Spells

111.1. A spell is a card on the stack. As the first step of being cast (see rule 601, "Casting Spells"), the card becomes a spell and is moved to the top of the stack from the zone it was in, which is usually its owner's hand. (See rule 405, "Stack.") A spell remains on the stack as a spell until it resolves (see rule 608, "Resolving Spells and Abilities"), is countered (see rule 701.5), or otherwise leaves the stack. For more information, see section 6, "Spells, Abilities, and Effects."

302 Creatures

302.1. A player who has priority may cast a creature card from his or her hand during a main phase of his or her turn when the stack is empty. Casting a creature as a spell uses the stack. (See rule 601, "Casting Spells.")

302.2. When a creature spell resolves, its controller puts it onto the battlefield under his or her control.

Xenograft only affects creatures on the battlefield:

603.6b Continuous effects that modify characteristics of a permanent do so the moment the permanent is on the battlefield (and not before then). The permanent is never on the battlefield with its unmodified characteristics. Continuous effects don't apply before the permanent is on the battlefield, however (see rule 603.6e).

user1873's answer also covers this well.

Answer 2

Hackworth's answer doesn't cover the situation where a creature is being modified as it is entering the battlefield, nor the situation where another continuous effect with a more recent timestamp is modifying that layer. In that situation, Xenograft doesn't work.

Xenograft is a Static Ability with a Continuous Effect.

604.3a A static ability is a characteristic-defining ability if it meets the following criteria: (1) It defines an object’s colors, subtypes, power, or toughness;

603.6b Continuous effects that modify characteristics of a permanent do so the moment the permanent is on the battlefield (and not before then). The permanent is never on the battlefield with its unmodified characteristics. Continuous effects don't apply before the permanent is on the battlefield, however (see rule 603.6e).

Example: If an effect reads "All lands are creatures" and a land card is played, the effect makes the land card into a creature the moment it enters the battlefield, so it would trigger abilities that trigger when a creature enters the battlefield. Conversely, if an effect reads "All creatures lose all abilities" and a creature card with an enters-the-battlefield triggered ability enters the battlefield, that effect will cause it to lose its abilities the moment it enters the battlefield, so the enters-the-battlefield ability won't trigger.

Xenograft will not apply to is replacement effects that modify a creature AS it is entering the battlefield. From the 4th Ruling of Bramblewood Paragon:

4/1/2008 The creature gets the counter if its copiable characteristics as it would exist on the battlefield include the specified creature type. For example, say you control Conspiracy, and the chosen creature type is Warrior. If you put a creature onto the battlefield that isn't normally a Warrior, it won't get a counter from Bramblewood Paragon.

Additionally, Xenograft doesn't apply to (as the rulings say)

Creature cards not on the battlefield and creature spells are not affected.

Creature cards can exist in zones other than the battlefield (hand, exile, graveyard, out of the game, etc.), but you can only control creature (permanents) on the battlefield, not any other place. Xenograft only affects creatures you control, so it cannot apply to cards in other zones.

108.4. A card doesn’t have a controller unless that card represents a permanent or spell; in those cases, its controller is determined by the rules for permanents or spells. See rules 110.2 and 111.2.

Creature spells can only exist on the stack, not any other place.

111.1. A spell is a card on the stack.

Xenograft only affects creatures on the battlefield, so it cannot apply to spells.

Finally, if another continuous effect modified the same layer as Xenograft, it the ability that generated that continuous effect had a more recent timestamp, Xenograft's continuous effect would be overridden.

613.1d Layer 4: Type-changing effects are applied. These include effects that change an object’s card type, subtype, and/or supertype.

613.2. Within layers 1–6, apply effects from characteristic-defining abilities first (see rule 604.3), then all other effects in timestamp order (see rule 613.6). Note that dependency may alter the order in which effects are applied within a layer. (See rule 613.7.)

Answer 3

The answers here are good but I would like to give some examples to help understand things. I will also cover how Xenograft is different from Conspiracy and Arcane Adaptation.

The basic idea is every creature you control has the type chosen with Xenograft added to it as it enters the battlefield, and keeps that type as long as it is on the battlefield. Conspiracy or Adaptation adds those types to the cards wherever they are (hand, deck, grave, stack, etc) while the enchantment in play.

This means you cannot search for something that is not naturally an elf using Elvish Harbinger or Nissa Revane's ultimate with Xenograft in play, but can with the other two. It means you can counter something not naturally a Faerie using Faerie Trickery. Because until they are entering the battlefield, Xenograft has no effect on them, but the other two do. Door of Destinies will not have a counter added if the same type was chosen for it and Xenograft, but will have the counter added for casting creatures due to Conspiracy or Adaptation. You can't use March from the Tomb to return creatures from the graveyard not printed as Allies using Xenograft, but can with the other two. With Silvergill Adept you can only reveal cards printed with the type Merfolk from your hand using Xenograft, but can reveal any creature using the other two.

It does affect the spells while they are entering the battlefield, so anything that cares about that type of creatures entering the battlefield, all three enchantments will make Dragon Tempest trigger by adding the Dragon type.