Prowl

From MTG Salvation Wiki

Prowl is an alternative cost that appears on some Rogue creature cards. Prowl was introduced in Morningtide. Prowl was featured as rules card 3 of 5 in the Morningtide set.

From the Comprehensive Rules: 502.76. Prowl 502.76a 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.” Paying a spell’s prowl cost follows the rules for paying alternative costs in rules 409.1b and 409.1f–h. 502.76b If a source that assigned combat damage left play before combat damage resolved, its last known information is used to determine its controller and its creature types.

For your reference [CR 409.1b,f-h] 409.1b If the spell or ability is modal (uses the phrase “Choose one —” or “[specified player] chooses one —”), the player announces the mode choice. If the player wishes to splice any cards onto the spell, he or she reveals those cards in his or her hand. If the spell or ability has a variable mana cost (indicated by ) or some other variable cost, the player announces the value of that variable at this time. If the spell or ability has alternative, additional, or other special costs (such as buyback, kicker, or convoke costs), the player announces his or her intentions to pay any or all of those costs (see rule 409.1f). You can’t apply two alternative methods of playing or two alternative costs to a single spell or ability. Previously made choices (such as choosing to play a spell with flashback from his or her graveyard or choosing to play a creature with morph face down) may restrict the player’s options when making these choices. 409.1f The player determines the total cost of the spell or ability. Usually this is just the mana cost (for spells) or activation cost (for abilities). Some cards list additional or alternative costs in their text, and some effects may increase or reduce the cost to pay. Costs may include paying mana, tapping permanents, sacrificing permanents, discarding cards, and so on. The total cost is the mana cost, activation cost, or alternative cost, plus all cost increases and minus all cost reductions. Once the total cost is determined, it becomes “locked in.” If effects would change the total cost after this time, they have no effect. 409.1g If the total cost includes a mana payment, the player then has a chance to play mana abilities (see rule 411, “Playing Mana Abilities”). Mana abilities must be played before costs are paid. 409.1h The player pays the total cost in any order. Partial payments are not allowed. Example You play Death Bomb, which costs and has an additional cost of sacrificing a creature. You sacrifice Thunderscape Familiar, whose effect makes your black spells cost less to play. Because a spell’s total cost is “locked in” before payments are actually made, you pay , not , even though you’re sacrificing the Familiar.

[edit] 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, or whether you controlled such a permanent at the time it left play and its combat damage was on the stack. 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.