Prowl

Prowl
Keyword Ability
Type	Static
Introduced	Morningtide
Last used	Morningtide
Reminder Text	Prowl [cost] (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a (subtype).)
Statistics	9 cards 56% 44%
Scryfall Search
keyword:"prowl cost"

Prowl is an alternative cost that appears on some Rogue creature cards. Prowl was introduced in Morningtide.

Rules

From the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

• 702.76. Prowl
  • 702.76a Prowl is a static ability that functions on the stack. “Prowl [cost]” means “You may pay [cost] rather than pay this spell’s mana cost if a player was dealt combat damage this turn by a source that, at the time it dealt that damage, was under your control and had any of this spell’s creature types.” Casting a spell for its prowl cost follows the rules for paying alternative costs in rules 601.2b and 601.2f–h.

From the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

• 601.2. To cast a spell is to take it from where it is (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. Casting a spell includes proposal of the spell (rules 601.2a–d) and determination and payment of costs (rules 601.2f–h). To cast a spell, a player follows the steps listed below, in order. A player must be legally allowed to cast the spell to begin this process (see rule 601.3). If a player is unable to comply with the requirements of a step listed below while performing that step, the casting of the spell is illegal; the game returns to the moment before the casting of that spell was proposed (see rule 730, “Handling Illegal Actions”).
  • 601.2a To propose the casting of a spell, a player first moves that card (or that copy of a card) from where it is to the stack. It becomes the topmost object on the stack. It has all the characteristics of the card (or the copy of a card) associated with it, and that player becomes its controller. Any continuous effects that modify the characteristics of the spell as you start casting it begin as it is put on the stack (see rule 611.2f). The spell remains on the stack until it resolves, it’s countered, or a rule or effect moves it elsewhere.
  • 601.2b If the spell is modal, the player announces the mode choice (see rule 700.2). If the player wishes to splice any cards onto the spell (see rule 702.47), they reveal those cards in their hand. If the spell has alternative or additional costs that will be paid as it’s being cast such as buyback or kicker costs (see rules 118.8 and 118.9), the player announces their intentions to pay any or all of those costs (see rule 601.2f). A player can’t apply two alternative methods of casting or two alternative costs to a single spell. If the spell has a variable cost that will be paid as it’s being cast (such as an {X} in its mana cost; see rule 107.3), the player announces the value of that variable. If the value of that variable is defined in the text of the spell by a choice that player would make later in the announcement or resolution of the spell, that player makes that choice at this time instead of that later time. If a cost that will be paid as the spell is being cast includes hybrid mana symbols, the player announces the nonhybrid equivalent cost they intend to pay. If a cost that will be paid as the spell is being cast includes Phyrexian mana symbols, the player announces whether they intend to pay 2 life or a corresponding colored mana cost for each of those symbols. Previously made choices (such as choosing to cast a spell with flashback from a graveyard or choosing to cast a creature with morph face down) may restrict the player’s options when making these choices.
  • 601.2c The player announces their choice of an appropriate object or player for each target the spell requires. A spell may require some targets only if an alternative or additional cost (such as a kicker cost) or a particular mode was chosen for it; otherwise, the spell is cast as though it did not require those targets. Similarly, a spell may require alternative targets only if an alternative or additional cost was chosen for it. If the spell has a variable number of targets, the player announces how many targets they will choose before they announce those targets. In some cases, the number of targets will be defined by the spell’s text. Once the number of targets the spell has is determined, that number doesn’t change, even if the information used to determine the number of targets does. The same target can’t be chosen multiple times for any one instance of the word “target” on the spell. However, if the spell uses the word “target” in multiple places, the same object or player can be chosen once for each instance of the word “target” (as long as it fits the targeting criteria). If any effects say that an object or player must be chosen as a target, the player chooses targets so that they obey the maximum possible number of such effects without violating any rules or effects that say that an object or player can’t be chosen as a target. The chosen objects and/or players each become a target of that spell. (Any abilities that trigger when those objects and/or players become the target of a spell trigger at this point; they’ll wait to be put on the stack until the spell has finished being cast.)

    Example: If a spell says “Tap two target creatures,” then the same creature can’t be chosen twice; the spell requires two different legal targets. A spell that says “Destroy target artifact and target land,” however, can target the same artifact land twice because it uses the word “target” in multiple places.

  • 601.2d If the spell requires the player to divide or distribute an effect (such as damage or counters) among one or more targets, the player announces the division. Each of these targets must receive at least one of whatever is being divided.
  • 601.2e The game checks to see if the proposed spell can legally be cast. If the proposed spell is illegal, the game returns to the moment before the casting of that spell was proposed (see rule 730, “Handling Illegal Actions”).
  • 601.2f The player determines the total cost of the spell. Usually this is just the mana cost. Some spells have additional or alternative costs. Some effects may increase or reduce the cost to pay, or may provide other alternative costs. Costs may include paying mana, tapping permanents, sacrificing permanents, discarding cards, and so on. The total cost is the mana cost or alternative cost (as determined in rule 601.2b), plus all additional costs and cost increases, and minus all cost reductions. If multiple cost reductions apply, the player may apply them in any order. If the mana component of the total cost is reduced to nothing by cost reduction effects, it is considered to be {0}. It can’t be reduced to less than {0}. Once the total cost is determined, any effects that directly affect the total cost are applied. Then the resulting total cost becomes “locked in.” If effects would change the total cost after this time, they have no effect.
  • 601.2g If the total cost includes a mana payment, the player then has a chance to activate mana abilities (see rule 605, “Mana Abilities”). Mana abilities must be activated before costs are paid.
  • 601.2h The player pays the total cost. First, they pay all costs that don’t involve random elements or moving objects from the library to a public zone, in any order. Then they pay all remaining costs in any order. Partial payments are not allowed. Unpayable costs can’t be paid.

    Example: You cast Altar’s Reap, which costs {1}{B} and has an additional cost of sacrificing a creature. You sacrifice Thunderscape Familiar, whose effect makes your black spells cost {1} less to cast. Because a spell’s total cost is “locked in” before payments are actually made, you pay {B}, not {1}{B}, even though you’re sacrificing the Familiar.

  • 601.2i Once the steps described in 601.2a–h are completed, effects that modify the characteristics of the spell as it’s cast are applied, then the spell becomes cast. Any abilities that trigger when a spell is cast or put onto the stack trigger at this time. If the spell’s controller had priority before casting it, they get priority.

From the glossary of the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

Prowl

A keyword ability that may allow a spell to be cast for an alternative cost. See rule 702.76, “Prowl.”

Rulings

• At the time you play a spell that has prowl, you look back over the course of the turn to check if the prowl condition has been met. What matters is whether you controlled a permanent with any of the relevant creature types at the time it dealt combat damage. It doesn't matter whether you still control the permanent or if its creature types are still the same.

• Playing a card for its prowl cost doesn't change the timing of when you can play it. Only the cost is different.

• Although the prowl reminder text lists specific creature types, this is done for convenience only. The prowl card's current creature types are what actually matter. For example, if a card such as Conspiracy causes a prowl spell to be an Elf, then you can pay its prowl cost rather than its mana cost only if an Elf you controlled dealt combat damage to a player that turn.

• Prowl is optional. If you want, you can pay a spell's normal mana cost rather than pay its prowl cost.

• Some prowl cards have comes-into-play abilities or additional effects if their prowl costs were paid. You'll get them if you played the card by paying its prowl cost rather than its normal mana cost.

Trivia

• Prowl was featured as rules card 3 of 5 in the Morningtide set.