One-shot effects like the name allies are effects, which do not last for an extended period of time.
- 610. One-Shot Effects
- 610.1. A one-shot effect does something just once and doesn’t have a duration. Examples include dealing damage, destroying a permanent, creating a token, and moving an object from one zone to another.
- 610.2. Some one-shot effects create a delayed triggered ability, which instructs a player to do something later in the game (usually at a specific time) rather than as the spell or ability that’s creating the one-shot effect resolves. See rule 603.7.
- 610.3. Some one-shot effects cause an object to change zones “until” a specified event occurs. A second one-shot effect is created immediately after the specified event. This second one-shot effect returns the object to its previous zone.
- 610.3a If the specified event has already occurred when the initial one-shot effect would cause the object to change zones, the object doesn’t move.
- 610.3b An object returned to the battlefield this way returns under its owner’s control unless otherwise specified.
- 610.3c If multiple one-shot effects are created this way immediately after one or more simultaneous events, those one-shot effects are also simultaneous.
Example: Two Banisher Priests have each exiled a card. All creatures are destroyed at the same time by Day of Judgment. The two exiled cards are returned to the battlefield at the same time.
- One-Shot Effect
- An effect that does something just once and doesn’t have a duration. See rule 610, “One-Shot Effects.” See also Continuous Effects.
Some examples of one-shot effects include the following:
- Direct damage or burn, characterized by the card Lightning Bolt
- Lifegain, characterized by Healing Salve
- Land destruction, as represented by cards such as Sinkhole
- Fast mana sources, such as Dark Ritual or Seething Song
- Creature removal in the forms of Terror and Swords to Plowshares
Some of these one-shot effects also "replace" themselves in the form of cantrips. Often, a card will have a slightly heightened mana cost in exchange for the phrase "Draw a card" in the spell's text box. This allows little to no loss, and even the possibility of gaining card advantage and tempo.
Slowtrips are merely delayed cantrips that were introduced in Ice Age and Coldsnap. While they do not have the "immediate" effect of a cantrip, they still allow the card being played to replace itself. The text associated with a slowtrip is "Draw a card at the beginning of the next turn's upkeep."