412.3. Some static abilities apply while a spell is on the stack. These are often abilities that refer to countering the spell. Also, abilities that say “As an additional cost to play . . . ,” “You may pay [cost] rather than pay [this object]’s mana cost,” and “You may play [this object] without paying its mana cost” work while a spell is on the stack.
412.4. Some static abilities apply while a card is in any zone that you could play it from (usually your hand). These are limited to those that read, “You may play [this card] . . .,” “You can’t play [this card] . . .,” and “Play [this card] only . . . .”
412.5. Unlike spells and other kinds of abilities, static abilities can’t use an object’s last known information for purposes of determining how their effects are applied.
413.1. Each time all players pass in succession, the object (a spell, an ability, or combat damage) on top of the stack resolves. (See rule 416, “Effects.”)
413.2. Resolution of a spell or ability may involve several steps. These steps are followed in the order listed below.
413.2a If the spell or ability specifies targets, it checks whether the targets are still legal. A target that’s removed from play, or from the zone designated by the spell or ability, is illegal. A target may also become illegal if its characteristics changed since the spell or ability was played or if an effect changed the text of the spell. The spell or ability is countered if all its targets, for every instance of the word “target,” are now illegal. If the spell or ability is not countered, it will resolve normally, affecting only the targets that are still legal. If a target is illegal, the spell or ability can’t perform any actions on it or make the target perform any actions. If the spell or ability needs to know information about one or more targets that are now illegal, it will use the illegal targets’ current or last known information.
Example: Aura Blast is a white instant that reads, “Destroy target enchantment. Draw a card.” If the enchantment isn’t a legal target during Aura Blast’s resolution (say, if it has gained protection from white or left play), then Aura Blast is countered. Its controller doesn’t draw a card.
Example: Plague Spores reads, “Destroy target nonblack creature and target land. They can’t be regenerated.” Suppose the same animated land is chosen both as the nonblack creature and as the land, and the color of the creature land is changed to black before Plague Spores resolves. Plagues Spores isn’t countered because the black creature land is still a legal target for the “target land” part of the spell.
413.2b The controller of the spell or ability follows its instructions in the order written. However, replacement effects may modify these actions. In some cases, later text on the card may modify the meaning of earlier text (for example, “Destroy target creature. It can’t be regenerated” or “Counter target spell. If you do, put it on top of its owner’s library instead of into its owner’s graveyard.”) Don’t just apply effects step by step without thinking in these cases-read the whole text and apply the rules of English to the text.
413.2c If an effect offers any choices other than choices already made as part of playing the spell or ability, the player announces these while applying the effect. The player can’t choose an option that’s illegal or impossible. (For example, a player can’t avoid the consequences of not taking an optional action if he or she can’t meet all the immediate requirements of that action.) Drawing a card is never considered an impossible action, even if there are no cards in the affected player's library.
Example: A spell’s instruction reads, “You may sacrifice a creature. If you don’t, you lose 4 life.” A player who controls no creatures can’t choose the sacrifice option.
413.2d Some spells and abilities have multiple steps or actions, denoted by separate sentences or clauses. In these cases, the choices for the first action are made in APNAP order, and then the first action is processed simultaneously. Then the choices for the second action are made in APNAP order, and then that action is processed simultaneously, and so on. See rule 103.4.
413.2e If an effect gives a player the option to pay mana, he or she may play mana abilities before taking that action. If an effect specifically instructs or allows a player to play a spell during resolution, he or she does so by putting that spell on top of the stack, then continuing to play it by following the steps in rules 409.1a-i (except no player receives priority after it’s played). The currently resolving spell or ability then continues to resolve, which may include playing other spells this way. No other spells or abilities can normally be played during resolution.
413.2f If an effect requires information from the game (such as the number of creatures in play), the answer is determined only once, when the effect is applied. The effect uses the current information of a specific permanent if that permanent is still in play, or of a specific card in the stated zone; otherwise, the effect uses the last known information the object had before leaving that zone. There are two exceptions. If an effect deals damage divided among some number of creatures or players, the amount and division were determined as the spell or ability was put into the stack; see rule 402.6. Also, static abilities can’t use last known information; see rule 412.5. If the ability text states that an object does something, it’s the object as it exists (or most recently existed) that does it, not the ability.
413.2g An effect that refers to characteristics of an object checks only for the value of the specified characteristics, regardless of any related ones the object may also have.
Example: An effect that reads “Destroy all black creatures” destroys a white-and-black creature, but one that reads “Destroy all nonblack creatures” doesn’t.
413.2h A spell is put into play from the stack under the control of the spell’s controller (for permanents) or is put into its owner’s graveyard from the stack (for instants and sorceries) as the final step of the spell’s resolution.
413.2i If an effect could result in a tie, the text of the spell or ability that created the effect will specify what to do in the event of a tie. The Magic game has no default for ties.
414.1. To counter a spell is to move the spell from the stack to its owner’s graveyard. Countering an ability removes it from the stack. Spells and abilities that are countered don’t resolve and none of their effects occur.