General Rulings - 116

• 116.1 - A cost is an action or payment necessary to take another action or to stop another action from taking place. To pay a cost, a player carries out the instructions specified by the spell, ability, or effect that contains that cost. [CompRules 2009/07/08]
• 116.2 - If a cost includes a mana payment, the player paying the cost has a chance to activate mana abilities. Paying the cost to cast a spell or activate an activated ability follows the steps in Rule 601.2e through Rule 601.2g. [CompRules 2009/07/08]
• 116.3 - A player can't pay a cost unless he or she has the necessary resources to pay it fully. For example, a player with only 1 life can't pay a cost of 2 life, and a permanent that's already tapped can't be tapped to pay a cost. See Rule 202, "Mana Cost and Color," and Rule 602, "Activating Activated Abilities." [CompRules 2009/07/08]
• 116.3a - Paying mana is done by removing the indicated mana from a player's mana pool. (Players can always pay 0 mana.) If excess mana remains in that player's mana pool after making that payment, the player announces what mana is still there. [CompRules 2009/07/08]
• 116.3b - Paying life is done by subtracting the indicated amount of life from a player's life total. (Players can always pay 0 life.) [CompRules 2009/07/08]
• 116.4 - Some costs include an {X} or an X. See Rule 107.3. [CompRules 2009/07/08]
• 116.5 - Some costs are represented by {0}, or are reduced to {0}. The action necessary for a player to pay such a cost is the player's acknowledgment that he or she is paying it. Even though such a cost requires no resources, it is not automatically paid. [CompRules 2009/07/08]
• 116.5a - A spell whose mana cost is {0} must still be cast the same way as one with a cost greater than zero; it won't cast itself automatically. The same is true for an activated ability whose cost is {0}. [CompRules 2009/07/08]
• 116.6 - Some mana costs contain no mana symbols. This represents an unpayable cost. An ability can also have an unpayable cost if its cost is based on the mana cost of a spell with no mana cost. Attempting to cast a spell or activate an ability that has an unpayable cost is a legal action. However, attempting to pay an unpayable cost is an illegal action. [CompRules 2009/07/08]
• 116.6a - If an unpayable cost is increased by an effect or an additional cost is imposed, the cost is still unpayable. If an alternative cost is applied to an unpayable cost, including an effect that allows a player to cast a spell without paying its mana cost, the alternative cost may be paid. [CompRules 2009/07/08]
• 116.7 - What a player actually needs to do to pay a cost may be changed or reduced by effects. If the mana component of a cost is reduced to nothing by cost reduction effects, it is considered to be {0}. Paying a cost changed or reduced by an effect counts as paying the original cost. [CompRules 2009/07/08]
• 116.7a - If a cost would be reduced by an amount of mana represented by a hybrid mana symbol, the player paying that cost chooses one half of that symbol at the time the cost reduction is applied (see Rule 601.2e). If a colored half is chosen, the cost is reduced by one mana of that color (or, if the cost can't be reduced by one mana of that color, the cost is reduced by one generic mana). If a colorless half is chosen, the cost is reduced by an amount of generic mana equal to that half's number. [CompRules 2009/07/08]
• 116.8 - Some spells and abilities have additional costs. An additional cost is a cost listed in a spell's rules text, or applied to a spell or ability from another effect, that its controller must pay at the same time that player pays the spell's mana cost or the ability's activation cost. A cost is an additional cost only if it is phrased using the word "additional." Note that some additional costs are listed in keywords; see Rule 702. [CompRules 2009/07/08]
• 116.8a - Any number of additional costs may be applied to a spell as it's being cast or to an ability as it's being activated. The controller of the spell or ability announces his or her intentions to pay any or all of those costs as described in Rule 601.2b. [CompRules 2009/07/08]
• 116.8b - Some additional costs are optional. [CompRules 2009/07/08]
• 116.8c - Additional costs don't change a spell's mana cost, only what its controller has to pay to cast it. Spells and abilities that ask for that spell's mana cost still see the original value. [CompRules 2009/07/08]
• 116.8d - Some effects increase the cost to cast a spell or activate an ability without using the word "additional." Those are not additional costs, and are not considered until determining the total cost of a spell or ability as described in Rule 601.2e. [CompRules 2009/07/08]
• 116.9 - Some spells have alternative costs. An alternative cost is a cost listed in a spell's text, or applied to it from another effect, that its controller may pay rather than paying the spell's mana cost. Alternative costs are usually phrased, "You may <-action-> rather than pay <-this object's-> mana cost," or "You may cast <-this object-> without paying its mana cost." Note that some alternative costs are listed in keywords; see Rule 702. [CompRules 2009/07/08]
• 116.9a - Only one alternative cost can be applied to any one spell as it's being cast. The controller of the spell announces his or her intentions to pay that cost as described in Rule 601.2b. [CompRules 2009/10/01]
• 116.9b - Alternative costs are always optional. [CompRules 2009/07/08]
• 116.9c - An alternative cost doesn't change a spell's mana cost, only what its controller has to pay to cast it. Spells and abilities that ask for that spell's mana cost still see the original value. [CompRules 2009/07/08]
• 116.9d - If an alternative cost is being paid to cast a spell, any additional costs, cost increases, and cost reductions that affect that spell are applied to that alternative cost. (See Rule 601.2e.) [CompRules 2009/07/08]
• 116.10 - Each payment of a cost applies to only one spell, ability, or effect. For example, a player can't sacrifice just one creature to activate the activated abilities of two permanents that each require sacrificing a creature as a cost. Also, the resolution of a spell or ability doesn't pay another spell or ability's cost, even if part of its effect is doing the same thing the other cost asks for. [CompRules 2009/07/08]
• 116.11 - The actions performed when paying a cost may be modified by effects. Even if they are, meaning the actions that are performed don't match the actions that are called for, the cost has still been paid. [CompRules 2009/07/08]
  Example: A player controls Psychic Vortex, an enchantment with a cumulative upkeep cost of "Draw a card," and Obstinate Familiar, a creature that says "If you would draw a card, you may skip that draw instead." The player may decide to pay Psychic Vortex's cumulative upkeep cost and then draw no cards instead of drawing the appropriate amount. The cumulative upkeep cost has still been paid. [CompRules 2009/07/08]
• 116.12 - Some spells, activated abilities, and triggered abilities read, "<-Do something->. If <-a player-> <-does or doesn't->, <-effect->." or "<-A player-> may <-do something->. If <-that player-> <-does or doesn't->, <-effect->." The action <-do something-> is a cost, paid when the spell or ability resolves. The "If <-a player-> <-does or doesn't->" clause checks whether the player chose to pay an optional cost or started to pay a mandatory cost, regardless of what events actually occurred. [CompRules 2009/07/08]
  Example: You control Hesitation, an enchantment that says "When a player casts a spell, sacrifice Hesitation. If you do, counter that spell." A spell is cast, causing Hesitation's ability to trigger. Then an ability is played that exiles Hesitation. When Hesitation's ability resolves, you're unable to pay the "sacrifice Hesitation" cost. The spell is not countered. [CompRules 2009/10/01]
  Example: Your opponent has cast Gather Specimens, a spell that says "If a creature would enter the battlefield under an opponent's control this turn, it enters the battlefield under your control instead." You control a face-down Dermoplasm, a creature with morph that says "When Dermoplasm is turned face up, you may put a creature card with morph from your hand onto the battlefield face up. If you do, return Dermoplasm to its owner's hand." You turn Dermoplasm face up, and you choose to put a creature card with morph from your hand onto the battlefield. Due to Gather Specimens, it enters the battlefield under your opponent's control instead of yours. However, since you chose to pay the cost, Dermoplasm is still returned to its owner's hand. [CompRules 2009/07/08]
• 116.12a - Some spells, activated abilities, and triggered abilities read, "<-Do something-> unless you <-do something else->." This means the same thing as "You may <-do something else->. If you don't, <-do something->." [CompRules 2009/07/08]