352. Make necessary choices.

352.1. If the card is a spell, or has an effect that specifies a choice "As I am played," those choices are made now.

352.2. For Units , choose a valid Location where that Unit will be placed upon being Played.

352.2.a. By default, Valid locations include the controller’s Base or a Battlefield the controller controls.
352.2.b. Some Game Effects may grant players permission to play Units to locations that are not normally Valid . Such locations become Valid for the purposes of Playing the Unit. .

352.3. For Spells and Abilities that Move one or more Units , choose a valid Location as the Move Destination for each Move that will be performed.

352.4. If a card requires you to specifically choose one or more Game Objects , that choice is made now.

352.4.a. This does not include cards that affect one or more Game Objects based on criteria. Example: "Stun a unit at a battlefield" is a Choice. Example: "Kill all gear" is not a Choice.
352.4.b. This does not include making choices for Triggered Abilities of permanents, even if those abilities trigger when the permanent is played. Example: A unit with a triggered ability that says "When I'm played, kill a unit" does not require you to choose a target as it's played. The target will be chosen when the ability triggers. See rule 375. Triggered Abilities for more information.

352.5. Targeting

352.6. When a card Chooses one or more specific Game Objects to affect, it is Targeted.

352.7. In order to put a spell or ability on the chain, valid choices must be made for all targets.

352.8. A target is a valid choice if it meets all of the following requirements:

352.8.a. It is a permanent or rune on the board, a spell or ability on the chain, a player or zone, or specified explicitly or implicitly as being in some other zone. e.g., “Kill a unit” targets a unit on the board. e.g., “Recycle a unit from your trash” targets a unit card in your trash.
352.8.a.1. “Unit,” “gear,” and “rune” refer to objects on the Board unless specified otherwise.
352.8.a.2. “Spell” and “ability” refer to objects on the Chain unless specified otherwise.
352.8.a.3. “Facedown card” refers to a card in a Facedown Zone unless specified otherwise.
352.8.a.4. “Legend” refers to a legend in the Legend Zone.
352.8.a.5. “Chosen Champion” and “unit in the Champion Zone” refer to a unit in the Champion Zone unless specified otherwise.
352.8.b. It meets all targeting restrictions. e.g., A unit is a valid target for a spell that refers to a “unit at a battlefield,” “enemy unit,” “unit you control,” or “unit with Might 4 or greater” only if it meets the appropriate criteria.
352.8.c. It is not the spell or ability itself. e.g., A spell that says “Counter a spell” cannot target itself. e.g., An ability of a permanent can target that permanent, because abilities and their sources are separate objects.

352.9. If a spell or ability requires one or more players to choose objects, players, or zones that are not targets, those choices are made on resolution.

352.9.a. Passive abilities never have targets.
352.9.b. Replacement effects never have targets.
352.9.c. Units and gear never have targets, although their abilities may.

352.10. A game object, player, or zone mentioned in the text of a spell, activated ability, or triggered ability is a target UNLESS any of the following are true:

352.10.a. It is in a zone whose information status is not Public. e.g., “Ready a legend” targets a legend, because the Legend Zone is Public. e.g., “Return a unit from your trash to your hand” targets a unit card in your trash, because your trash is Public. e.g., “You may play a unit from your hand, ignoring its costs” does not target a unit card in your hand, because your hand is not a public zone.
352.10.a.1. Public zones are Battlefield Zones, Bases, Trashes, Legend Zones, Champion Zones, and Facedown Zones.
352.10.b. It is included only as part of a targeting restriction for another choice. e.g., “Kill a unit at a battlefield” targets a unit, but not a battlefield, because the units are targets and “at a battlefield” is a restriction. e.g., “Kill all units at a battlefield” targets a battlefield, but not any units. e.g., “Move a unit to a battlefield” targets both a unit and a battlefield.
352.10.c. It is included only as part of a cost, trigger condition, or replacement effect. e.g., “As an additional cost to play me, kill a friendly unit” doesn’t target anything. e.g., “When a friendly unit dies, kill a gear” targets a gear, but not a friendly unit. e.g., “When you play me, the next time a friendly unit would die this turn, return it to your hand instead” doesn’t target anything. The replacement effect applies when any friendly unit dies. e.g., “Choose a friendly unit. The next time it would die this turn, return it to your hand instead” targets a friendly unit, because “choose a friendly unit” is not part of the replacement effect.
352.10.c.1. This includes costs within instructions, identified by phrases like “[do X] to [do Y].” The cost within that instruction is “[do X].” e.g., “When I hold, you may kill another friendly unit here to draw 1” does not target anything. e.g., “When you play me, you may spend a buff to move a friendly unit” targets the friendly unit, but not the buff.
352.10.d. It is programmatically selected based on its characteristics rather than chosen by the spell or ability’s controller. e.g., “Kill all units at a battlefield” targets a battlefield, but does not target any units. e.g., “Kill all units at battlefields” doesn’t target anything. e.g., “Destroy a unit. Its controller draws 2 cards” targets the unit, but not its controller. e.g., “Ready your legend” doesn’t target anything, because you can only have one legend. e.g., “Ready a friendly legend” targets a legend, because in a 2v2 game there are two friendly legends. e.g., “Recycle all cards in your trash” doesn’t target anything, because it affects all cards and you only have one trash.
352.10.d.1. This exception applies solely to objects for which no choice is ever possible.
352.10.d.2. This exception does not apply to objects that are the only valid choice at the moment a spell or ability is placed on the chain, but which would require a choice under other circumstances. e.g., “Kill a unit at a battlefield” always targets a unit, even if that unit is the only unit currently at a battlefield.
352.10.e. It is part of a set of objects chosen in whole or in part by other players. e.g., “Each player kills a unit they control” does not target. Each player, including the one who played the spell, chooses a unit to kill as the spell or ability resolves.
352.10.f. It is identified in an instruction that a player “must” complete. e.g., “You must recycle one of your runes” doesn’t target anything. You choose from among your runes as the spell or ability resolves. e.g., “Recycle a rune you control” targets a rune. You choose a rune you control as you put the spell or ability on the chain.

352.11. Some cards identify a group of Targets with Targeting Requirements that must be met by the group as a whole.

352.11.a. As they’re finalized on the chain, such cards can choose any group of valid targets that collectively fulfill the targeting restriction.
352.11.b. If the group of targets no longer collectively fulfill the targeting restriction as the spell or ability resolves, that spell or ability’s controller can choose a subset of the original targets that fulfills the targeting requirement for the spell or ability to affect. Example: A player plays Fox-Fire, a spell that says in part “Kill any number of units at a battlefield with total Might 4 or less.” That player chooses four 1 [M] Recruit tokens at a single battlefield. As a Reaction, another player gives two of those Recruits +1 [M], so the Recruits’ Mights are 1, 1, 2, and 2. Then Fox-Fire resolves. The Recruits no longer have total Might 4 or less, so Fox-Fire’s controller must choose a legal subset of the original targets to affect. They could choose to kill the two 2 [M] Recruits, or the two 1 [M] Recruits plus one 2 [M] Recruit. The units they choose are Fox-Fire’s remaining legal targets. They can’t choose to affect units at the same battlefield that weren’t initially chosen as targets, and they can’t affect any units that are no longer at the chosen battlefield.

352.12. If a card specifies that a player may choose some number of Game Objects to be affected by a card, then all choices are considered targeted and chosen independently.

352.13. If a card specifies that a player chooses “any number” or “up to” some number of Game Objects to be affected, they may choose any number of available targets, including zero. If they choose zero, the spell or ability can be played without any targets.

352.14. Splitting

352.14.a. If a card specifies that an amount of damage may be split among some number of Units , then each Unit chosen is Targeted.
352.14.b. The Targets are chosen when the spell or ability is finalized on the chain.
352.14.c. A number of Targets can only be chosen up to, and not exceeding, the initial amount of damage available when the spell is played. Example: A player playing a spell that instructs them to "Split 5 damage" may only choose up to 5 units, but may choose fewer.
352.14.d. Each Target is valid, and contributes to Chosen triggers individually.
352.14.e. The choice of how much damage is divided across the split is not decided until the resolution of the spell or ability.
352.14.f. Each Target must receive a valid amount of damage.
352.14.g. Valid damage is a positive integer amount, greater than or equal to 1 damage.
352.14.h. If, at resolution of the spell or effect, there are more Targets than available damage to divide, then the player who controls the effect dealing damage determines which Targets cease being Targets.
352.14.i. Any costs that were paid, or effects that were triggered as a result of those Game Objects being chosen as Targets remain in effect, paid, or otherwise triggered.

352.15. These choices cannot be changed after this step.

352.16. A player may not make choices during this step that will deterministically result in illegal choices or actions later in this process unless they have no choice. Example: A player plays Cruel Patron, which says "As an additional cost to play me, kill a friendly unit." They control exactly one unit, which is at a battlefield. They can't choose to play Cruel Patron to that battlefield, because by the time they have finished paying costs, they will no longer control that battlefield.