Most of the time, the Magic game uses only positive numbers and zero. You can't choose a negative number, deal negative damage, gain negative life, and so on. However, it's possible for a game value, such as a creature's power, to be less than zero. If a calculation or comparison needs to use a negative value, it does so. If a calculation that would determine the result of an effect yields a negative number, zero is used instead, unless that effect sets a player's life total to a specific value, doubles a player's life total, sets a creature's power or toughness to a specific value, or otherwise modifies a creature's power or toughness.

Example: If a 3/4 creature gets -5/-0, it's a -2/4 creature. It assigns 0 damage in combat. Its total power and toughness is 2. You'd have to give it +3/+0 to raise its power to 1.

Example: Viridian Joiner is a 1/2 creature with the ability "{T}: Add to your mana pool an amount of {G} equal to Viridian Joiner's power." An effect gives it -2/-0, then its ability is activated. The ability adds no mana to your mana pool.

Most of the time, the Magic game uses only positive numbers and zero. You can't choose a negative number, deal negative damage, gain negative life, and so on. However, it's possible for a game value, such as a creature's power, to be less than zero. If a calculation or comparison needs to use a negative value, it does so. If a calculation that would determine the result of an effect yields a negative number, zero is used instead, unless that effect sets a player's life total to a specific value, doubles a player's life total, sets a creature's power or toughness to a specific value, or otherwise modifies a creature's power or toughness.

Example: If a 3/4 creature gets -5/-0, it's a -2/4 creature. It doesn't assign damage in combat. Its total power and toughness is 2. You'd have to give it +3/+0 to raise its power to 1.

Example: Viridian Joiner is a 1/2 creature with the ability "{T}: Add to your mana pool an amount of {G} equal to Viridian Joiner's power." An effect gives it -2/-0, then its ability is activated. The ability adds no mana to your mana pool.

If an effect instructs a player to name a card, the player must choose the name of a card that exists in the Oracle card reference (see rule 108.1) and is legal in the format of the game the player is playing. (See rule 100.6.) If the player wants to name a split card, the player must name both halves of the split card. (See rule 708.) If the player wants to name a flip card's alternative name, the player may do so. (See rule 709.) If the player wants to name the back face of a double-faced card, the player may do so. (See rule 711.) A player may not choose the name of a token unless it's also the name of a card.

If an effect instructs a player to name a card, the player must choose the name of a card that exists in the Oracle card reference (see rule 108.1) and is legal in the format of the game the player is playing. (See rule 100.6.) If the player wants to name a split card, the player must choose the name of one of its halves, but not both. (See rule 708.) If the player wants to name a flip card's alternative name, the player may do so. (See rule 709.) If the player wants to name the back face of a double-faced card, the player may do so. (See rule 711.) A player may not choose the name of a token unless it's also the name of a card.

Planeswalkers have their own unique set of subtypes; these subtypes are called planeswalker types. The planeswalker types are Ajani, Bolas, Chandra, Domri, Elspeth, Garruk, Gideon, Jace, Karn, Koth, Liliana, Nissa, Sarkhan, Sorin, Tamiyo, Tezzeret, Tibalt, Venser, and Vraska. If two or more planeswalkers that share a planeswalker type are on the battlefield, all are put into their owners' graveyards. This "planeswalker uniqueness rule" is a state-based action. See rule 704.

Planeswalkers have their own unique set of subtypes; these subtypes are called planeswalker types. The planeswalker types are Ajani, Bolas, Chandra, Domri, Elspeth, Garruk, Gideon, Jace, Karn, Koth, Liliana, Nissa, Ral, Sarkhan, Sorin, Tamiyo, Tezzeret, Tibalt, Venser, and Vraska. If two or more planeswalkers that share a planeswalker type are on the battlefield, all are put into their owners' graveyards. This "planeswalker uniqueness rule" is a state-based action. See rule 704.

An ability that reads "Whenever [this creature] attacks and isn't blocked, . . ." triggers if no creatures are declared as blockers for that creature. It won't trigger if the attacking creature is blocked and then all its blockers are removed from combat.

An ability that reads "Whenever [this creature] attacks and isn't blocked, . . ." triggers if no creatures are declared as blockers for that creature. It will trigger even if the creature was never declared as an attacker (for example, if it entered the battlefield attacking). It won't trigger if the attacking creature is blocked and then all its blockers are removed from combat.

If an effect of a spell or ability offers any choices other than choices already made as part of casting the spell, activating the ability, or otherwise putting the spell or ability on the stack, the player announces these while applying the effect. The player can't choose an option that's illegal or impossible, with the exception that having library with no cards in it doesn't make drawing a card an impossible action (see rule 120.3). If an effect divides or distributes something, such as damage or counters, as a player chooses among any number of untargeted players and/or objects, the player chooses the amount and division such that at least one player or object is chosen if able, and each chosen player or object receives at least one of whatever is being divided. (Note that if an effect divides or distributes something, such as damage or counters, as a player chooses among some number of target objects and/or players, the amount and division were determined as the spell or ability was put onto the stack rather than at this time; see rule 601.2d.)

Example: A spell's instruction reads, "You may sacrifice a creature. If you don't, you lose 4 life." A player who controls no creatures can't choose the sacrifice option.

If an effect of a spell or ability offers any choices other than choices already made as part of casting the spell, activating the ability, or otherwise putting the spell or ability on the stack, the player announces these while applying the effect. The player can't choose an option that's illegal or impossible, with the exception that having a library with no cards in it doesn't make drawing a card an impossible action (see rule 120.3). If an effect divides or distributes something, such as damage or counters, as a player chooses among any number of untargeted players and/or objects, the player chooses the amount and division such that at least one player or object is chosen if able, and each chosen player or object receives at least one of whatever is being divided. (Note that if an effect divides or distributes something, such as damage or counters, as a player chooses among some number of target objects and/or players, the amount and division were determined as the spell or ability was put onto the stack rather than at this time; see rule 601.2d.)

Example: A spell's instruction reads, "You may sacrifice a creature. If you don't, you lose 4 life." A player who controls no creatures can't choose the sacrifice option.

A creature can't have a greater power or toughness than a noncreature permanent.

A creature can't have a greater power or toughness than a noncreature permanent.

If a creature has multiple instances of evolve, each triggers separately.

If a creature has multiple instances of evolve, each triggers separately.

In every zone except the stack, split cards have two sets of characteristics and two converted mana costs. As long as a split card is a spell on the stack, only the characteristics of the half being cast exist. The other half's characteristics are treated as though they didn't exist.

In every zone except the stack, split cards have two sets of characteristics and two converted mana costs. As long as a split card is a spell on the stack and wasn't cast using fuse (see rule 702.100, "Fuse"), only the characteristics of the half being cast exist. The other half's characteristics are treated as though they didn't exist. A split card that's a spell on the stack and was cast using fuse has two sets of characteristics and one converted mana cost. Its converted mana cost is equal to the total amount of mana in its two mana costs, regardless of color.

If a player casts a split card, that player chooses which half of that split card he or she is casting before putting it onto the stack. Only the half that is being cast is considered to be put onto the stack. Only that half is evaluated to see if it can be cast.

If a player casts a split card without using fuse, that player chooses which half of that split card he or she is casting before putting it onto the stack. Only that half is evaluated to see if it can be cast. Only that half is considered to be put onto the stack.

Each split card that consists of two halves with different colored mana symbols in their mana costs is a multicolored card while it's not a spell on the stack. While it's a spell on the stack, it's only the color or colors of the half being cast.

Each split card that consists of two halves with different colored mana symbols in their mana costs is a multicolored card while it's not a spell on the stack. While it's a spell on the stack, it's only the color or colors of the half or halves being cast.

An effect that asks for a particular characteristic of a split card while it's in a zone other than the stack gets two answers (one for each of the split card's two halves).

Example: Infernal Genesis has an ability that reads, "At the beginning of each player's upkeep, that player puts the top card from his or her library into his or her graveyard. He or she then puts X 1/1 black Minion creature tokens onto the battlefield, where X is that card's converted mana cost." If the top card of your library is Assault/Battery when this ability resolves, the game sees its converted mana cost as "1, and 4." You get five creature tokens.

Anything that asks for a particular characteristic of a split card while it's in a zone other than the stack gets two answers (one for each of the split card's two halves). Anything that asks for a particular characteristic of a fused split spell gets two answers. Anything that asks for a particular characteristic of a split card while it's a spell on the stack or that asks for the converted mana cost of a fused split spell gets one answer.

Example: Infernal Genesis has an ability that reads, "At the beginning of each player's upkeep, that player puts the top card from his or her library into his or her graveyard. He or she then puts X 1/1 black Minion creature tokens onto the battlefield, where X is that card's converted mana cost." If the top card of your library is Assault/Battery, which has converted mana costs of 1 and 4, when this ability resolves, you simultaneously put one and four creature tokens onto the battlefield, for a total of five.

Example: Spell Blast says "Counter target spell with converted mana cost X." If a player wants to cast Spell Blast and choose the fused split spell Breaking/Entering, which has mana costs {U}{B} and {4}{B}{R}, as the target, that player must choose 8 as the value of X.

Some effects perform comparisons involving characteristics of one or more split cards in a zone other than the stack.

Some effects perform comparisons involving one or more split cards in a zone other than the stack or involving one or more fused split spells.

An effect that performs a positive comparison (such as asking if a card is red) or a relative comparison (such as asking if a card's converted mana cost is less than 2) involving characteristics of one or more split cards in any zone other than the stack gets only one answer. This answer is "yes" if either side of each split card in the comparison would return a "yes" answer if compared individually.

Example: Void reads, "Choose a number. Destroy all artifacts and creatures with converted mana cost equal to that number. Then target player reveals his or her hand and discards all nonland cards with converted mana cost equal to the number." If a player casts Void and chooses 1, his or her opponent would discard Assault/Battery because the game sees its converted mana cost as "1, and 4." The same is true if the player chooses 4. If the player chooses 5, however, Assault/Battery would be unaffected.

Anything that performs a positive comparison (such as asking if a card is red) or a relative comparison (such as asking if a card's converted mana cost is 3 or less) involving one or more split cards in any zone other than the stack or involving one or more fused split spells gets only one answer. This answer is "yes" if either side of each split card in the comparison would return a "yes" answer if compared individually.

Example: Void reads, "Choose a number. Destroy all artifacts and creatures with converted mana cost equal to that number. Then target player reveals his or her hand and discards all nonland cards with converted mana cost equal to the number." If a player casts Void and chooses 1, his or her opponent would discard Assault/Battery because its converted mana costs are 1 and 4. The same is true if the player chooses 4. If the player chooses 5, however, Assault/Battery would be unaffected.

An effect that performs a negative comparison (such as asking if cards have different names) involving characteristics of one or more split cards in any zone other than the stack also gets only one answer. This answer is "yes" if performing the analogous positive comparison would return a "no" answer.

Anything that performs a negative comparison (such as asking if cards have different names) involving one or more split cards in any zone other than the stack or involving one or more fused split spells also gets only one answer. This answer is "yes" if performing the analogous positive comparison would return a "no" answer.

If an effect performs a comparison involving multiple characteristics of one or more split cards in any zone other than the stack, each characteristic is compared separately. If each of the individual comparisons would return a "yes" answer, the whole comparison returns a "yes" answer.

If anything performs a comparison involving multiple characteristics or values of one or more split cards in any zone other than the stack or involving multiple characteristics or values of one or more fused split spells, each characteristic or value is compared separately. If each of the individual comparisons would return a "yes" answer, the whole comparison returns a "yes" answer. The individual comparisons may involve different halves of the same split card.

Example: Sunforger has an ability that reads, "{R}{W},Unattach Sunforger: Search your library for a red or white instant card with converted mana cost 4 or less and cast that card without paying its mana cost. Then shuffle your library." This ability can be used to cast either half of Research/Development, as Research has converted mana cost 2 (even though Development has converted mana cost 5) and Development is red (even though Research is neither red nor white).

If an effect instructs a player to name a card and the player wants to name a split card, the player must name both halves of the split card. An object has the chosen name if it has at least one of the two names chosen this way.

Each split card has two names. If an effect instructs a player to name a card and the player wants to name a split card, the player must name one of those names and not both. An object has the chosen name if one of its names is the chosen name.

At the end of a subgame of a Vanguard game, each player moves his or her vanguard card from the subgame command zone to the main-game command zone.

At the end of a subgame of a Vanguard game, each player moves his or her vanguard card from the subgame command zone to the main-game command zone. This is an exception to rule 311.2.

If an effect needs to know how many poison counters an individual player has, that effect uses the number of poison counters that player's team has.

If an effect needs to know how many poison counters an individual player has, that effect uses the number of poison counters that player's team has. If an effect needs to know how many poison counters a player's opponents have, that effect uses the number of poison counters opposing teams have.