Abandon
To turn a face-up ongoing scheme card face down and put it on the bottom of its owner’s scheme deck. See rule 701.24, "Abandon."

Ability
1. Text on an object that explains what that object does or can do.
2. An activated or triggered ability on the stack. This kind of ability is an object.
See rule 112, "Abilities," and section 6, "Spells, Abilities, and Effects."

Ability Word
An italicized word with no rules meaning that ties together abilities on different cards that have similar functionality. See rule 207.2c.

Absorb
A keyword ability that prevents damage. See rule 702.63, "Absorb."

Activate
To put an activated ability onto the stack and pay its costs, so that it will eventually resolve and have its effect. See rule 602, "Activating Activated Abilities."

Activated Ability
A kind of ability. Activated abilities are written as "[Cost]: [Effect.] [Activation instructions (if any).]" See rule 112, "Abilities," and rule 602, "Activating Activated Abilities."

Activation Cost
Everything that appears before the colon in an activated ability’s text. It must be paid to activate the ability. See rule 117, "Costs," and rule 602, "Activating Activated Abilities."

Active Player
The player whose turn it is. See rule 102.1.

Active Player, Nonactive Player Order
A system that determines the order by which players make choices if multiple players are instructed to make choices at the same time. See rule 101.4. This rule is modified for games using the shared team turns option; see rule 805.6.

Active Team
The team whose turn it is in a game using the shared team turns option. See rule 805.4a.

Additional Cost
A cost a spell may have that its controller may pay (or, in some cases, must pay) in addition to its mana cost to cast that spell. See rule 117, "Costs," and rule 601, "Casting Spells."

Affinity
A keyword ability that reduces how much mana you need to spend to cast a spell. See rule 702.40, "Affinity."

Afflict
A keyword ability that makes the defending player lose life for blocking. See rule 702.129, "Afflict."

Aftermath
A keyword ability that lets a player cast one half of a split card only from his or her graveyard. See rule 702.126, "Aftermath."

Alternating Teams Variant
A multiplayer variant played among two or more teams of equal size. See rule 811, "Alternating Teams Variant."

Alternative Cost
A cost a spell may have that its controller can pay rather than paying its mana cost. See rule 117, "Costs," and rule 601, "Casting Spells."

Amplify
A keyword ability than can have a creature enter the battlefield with +1/+1 counters on it. See rule 702.37, "Amplify."

Anchor Word
A word that precedes one of two abilities a permanent may enter the battlefield with. See rule 614.12b.

Annihilator
A keyword ability that can make a creature particularly brutal when it attacks. See rule 702.85, "Annihilator."

Ante
1. A zone used only when playing "for keeps."
2. To put a card into the ante zone.
See rule 407, "Ante."

APNAP Order
See Active Player, Nonactive Player Order.

Archenemy
1. A casual variant in which a team of players faces off against a single opponent strengthenedwith powerful scheme cards. See rule 904, "Archenemy."
2. A player in an Archenemy game who is playing with a scheme deck.

Artifact
A card type. An artifact is a permanent. See rule 301, "Artifacts."

Artifact Creature
A combination of artifact and creature that’s subject to the rules for both. See rule 301, "Artifacts," and rule 302, "Creatures."

Artifact Land
A combination of artifact and land that’s subject to the rules for both. Artifact lands can only be played as lands, not cast as spells. See rule 301, "Artifacts," and rule 305, "Lands."

Artifact Type
A subtype that’s correlated to the artifact card type. See rule 301, "Artifacts." See rule 205.3g for the list of artifact types.

As Though
Text used to indicate that the game, for some specific purpose, treats a condition as true even though it’s not. See rule 609.4.

Assign Combat Damage
To determine how an attacking or blocking creature will deal its combat damage. See rule 510, "Combat Damage Step."

At End of Turn (Obsolete)
A trigger condition printed on abilities that triggered at the beginning of the end step (which is not the last thing to happen in the turn). Cards that were printed with that text have received errata in the Oracle card reference to say"at the beginning of the end step" or "at the beginning of the next end step." See rule 513, "End Step."

Attach
To move an Aura, Equipment, or Fortification onto another object. See rule 701.3, "Attach."

Attack
To send a creature into combat offensively. A creature can attack a player or a planeswalker. See rule 508, "Declare Attackers Step."

Attack Alone
A creature "attacks alone" if it’s the only creature declared as an attacker during the declare attackers step. A creature "is attacking alone" if it’s attacking but no other creatures are. See rule 506.5.

Attack Left Option
An option that may be used in certain multiplayer variants. See rule 803, "Attack Left and Attack Right Options."

Attack Multiple Players Option
An option that may be used in certain multiplayer variants. See rule 802, "Attack Multiple Players Option."

Attack Right Option
An option that may be used in certain multiplayer variants. See rule 803, "Attack Left and Attack Right Options."

Attacking Creature
A creature that has either been declared as part of a legal attack during the combat phase (once all costs to attack, if any, have been paid), or a creature that has been put onto the battlefield attacking. It remains an attacking creature until it’s removed from combat or the combat phase ends, whichever comes first. See rule 508, "Declare Attackers Step."

Attacks and Isn’t Blocked
An ability that triggers when a creature "attacks and isn’t blocked" triggers when the creature becomes an unblocked attacking creature. See rule 509.1h.

Aura
An enchantment subtype. Aura spells target objects or players, and Aura permanents are attached to objects or players. See rule 303, "Enchantments," and rule 702.5, "Enchant."

Aura Swap
A keyword ability that lets you exchange an Aura on the battlefield with one in your hand. See rule 702.64, "Aura Swap."

Awaken
A keyword ability that lets you turn a land you control into a creature. See rule 702.112, "Awaken."