Priority and playing Activated Abilities

[The Legacy Weapon]

Hi again.

I recently had a new guy join our MTG group and he seems to be a little confused about the way Priority works as well as what happens when an Activated Ability gets played. First, I'll give you the situation that started the argument.

He was playing his Elf Staff of Dominance deck and went off on his turn. He drew a bunch of cards and played alot of elves among other creatures and passed his turn because his plan was to swing in at everybody on his next turn. (Keep in mind that none of the creatures he played had more than 5 toughness.) My other friend got to his turn and had 6 lands on his upkeep as well as a Jaya Ballard, Task Mage that had just lost summoning sickness. He draws his card and then goes to main phase 1 (precombat...whatever you call it.) He plays his land and announces that he wants to use Jaya Ballard's 3rd ability which hits all creatures and all players for 6 damage. Elf player starts telling his girlfriend that she needs to tap down the Jaya Ballard in response to him trying to tap the Jaya. I explained to him that before any responses can be made, the ability has to have been placed on the stack and before the ability can be put on the stack, all costs would have to be paid. He strongly disagreed and said I would have to prove it to him with the rulebook.

Thats where I'm at. I just need help getting it through his head and if maybe someone here could explain how priority and playing activated abilities works a little more clearly for this guy, maybe he will come around. Thanks in advance.

[cdr]

An ability existing independent of its source is just sort of "common sense" once you get a feel for Magic rules. However, since it's a common question for newer players, there is a section in the rules about it:


402. Abilities

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402.6. Once activated or triggered, an ability exists independently of its source as an ability on the stack. Destruction or removal of the source after that time won't affect the ability. Note that some abilities cause a source to do something (for example, "Prodigal Sorcerer deals 1 damage to target creature or player") rather than the ability doing anything directly. In these cases, any activated or triggered ability that references information about the source because the effect needs to be divided checks that information when the ability is put onto the stack. Otherwise, it will check that information when it resolves. In both instances, if the source is no longer in play, its last known information is used.

The other potential source of confusion is that you can't do anything about the Jaya becoming tapped; tapping it is a cost, which happens as part of playing the ability without anyone getting priority.


409. Playing Spells and Activated Abilities

409.1. Playing a spell or activated ability follows the steps listed below, in order. If, at any point during the playing of a spell or ability, a player is unable to comply with any of the steps listed below, the spell was played illegally; the game returns to the moment before that spell or ability was played (see rule 422, "Handling Illegal Actions"). Announcements and payments can't be altered after they've been made.

409.1a. The player announces that he or she is playing the spell or activated ability. If a spell is being played, that card (or that copy of a card) physically moves from the zone it's in to the stack. It has all the characteristics of the card (or the copy of a card) associated with it, and its controller is the player who played it. If an activated ability is being played, it's created on the stack as an object that's not a card. If an activated ability is being played from a hidden zone, the card that has that ability is revealed. On the stack, the ability has the text of the ability that created it, and no other characteristics. Its controller is the player who played the ability. The spell or ability remains on the stack until it's countered or resolves.

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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. 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, activation cost, or alternative cost (as determined in rule 409.1b), plus all additional costs and cost increases, and minus all cost reductions. 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, 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. Unpayable costs can't be paid.

409.1i. Once the steps described in 409.1a-h are completed, the spell or ability becomes played. Any abilities that trigger on a spell or ability being played or put onto the stack trigger at this time. If the spell or ability's controller had priority before playing it, he or she gets priority.


Priority: The player who has the option to play a spell or ability at any given time has priority. See rule 408, "Timing of Spells and Abilities." Each time a spell, an ability (other than a mana ability), or combat damage resolves, and at the beginning of most phases and steps, the active player receives priority. If a player has priority when he or she plays a spell, ability, or land, or takes a special action, he or she receives priority afterward. When a player passes in a two-player game, his or her opponent receives priority. If all players pass in succession, the spell, ability, or combat damage on top of the stack resolves or, if the stack is empty, the phase or step ends. Each time a player would get priority, all applicable state-based effects resolve first as a single event (see rule 420). Then, if any new state-based effects have been generated, they resolve as a single event. This process repeats until no more applicable state-based effects are generated. Then triggered abilities are added to the stack (see rule 410). These steps repeat in order until no further state-based effects or triggered abilities are generated.

Of course, he could have tapped Jaya during upkeep and gotten the effect he wanted.