Cost

For other uses, see Cost (disambiguation).

A cost is a payment made for spells, activated abilities, or as part of effects. Costs are very commonly paid by spending mana, but sometimes other resources are required such as life or energy counters, or actions are demanded such as sacrificing permanents or discarding cards. Activation costs, the costs for activated abilities, frequently include tapping the permanent that has the ability. When an effect allows a player to pay a cost, that cost could be required or optional, depending on the effect, usually leading to additional effects based on the player paying and/or not paying.

A spell, ability or effect that requires specific actions as part of its cost implicitly grants players the ability to do things they wouldn't have otherwise been able to do. For example, players normally can't sacrifice permanents for no reason, or put permanents into play without casting them. But if a cost demands those actions, then the player can simply follow the instruction of the cost and take those actions. Similarly, players can't normally reduce their life total at will, but if a cost demands a life payment (or any other resource), then the life can be paid.

On the other hand, some effects explicitly prevent certain actions from being taken, like "cards can't leave graveyards", which would prevent costs requiring those actions from being taken, like "exile this card from your graveyard". But, replacement effects which change the results of cost-paying actions don't prevent the cost from being paid. For example, "if a creature would die, return it to its owner's hand instead" still allows you to sacrifice creatures, they just go back to your hand; and "if you would discard a card, your opponent discards one instead" still allows you to "pay the cost" of discarding despite your opponent actually taking the action.

Total cost

The total cost for a payment is determined by combining a starting cost with any cost increases and decreases that may apply, and includes all actions and resources required, not just mana. Spells almost always have a mana cost which establishes a base, but may have an alternative cost that could be used instead. Alternative costs include casting it "without paying its mana cost", which sets the base cost to 0. The base cost of an ability is its activation cost. Once the base cost is determined, any additional costs that apply are added, which may be in the card's text or imposed by another effect, as well as cost increases or decreases caused by other effects which are often phrased as "[thing] costs more [or less] to cast [or activate]". Notably, casting "without paying its mana cost" still allows the total cost to include mana payments, if they're due to cost increases.

The total cost of a payment demanded by the effect of a spell or ability is almost always simply what is stated in the effect text, since few to none of the cost-changing effects apply to payments for effects. For instance in an effect like "...that player may pay . If they don't, create a treasure token", the cost of is rarely modified by other effects.

Only after this total cost is fully determined is the payment made, all at once and in full. If the total cost can't be paid, then no sub-part of the cost can or must be paid either. For example a spell that costs with an additional cost of sacrificing a creature, cannot be paid for if the player either does not have the mana or has no creatures. The player cannot "try" to cast the spell by sacrificing a creature only. Similarly, a mandatory cost like "...exile two cards from your graveyard. If you can't..." will not force the player to exile one card from the graveyard if they only have one - it simply proceeds to the consequences because they couldn't exile two.

Mandatory costs

Some effects require a player to pay a cost if they are able to, usually with consequences if they cannot pay it. In this case, the player cannot willingly choose to take the consequences by not paying. (On the other hand, if the text says they "may" pay the cost, it is not mandatory.) Almost always, mandatory costs consist of actions involving permanents or cards, such as sacrificing permanents or exiling cards from the graveyard, and not payment of mana. In these cases it is clear whether the player can take the action or not - e.g. if they control the permanents or have the cards in graveyard, they can sacrifice or exile them, and must do so if mandatory.

A mandatory cost never forces players to take actions other than the cost itself, even if those actions would then allow the cost to be paid. In particular, mana abilities are never required to be used in order to pay a mandatory cost. Therefore, a player may feel like they could pay a mandatory cost like because they have an untapped land, but the game considers them to be "unable" to pay it at that time because they do not already have the required mana. Therefore, they are not required to pay it. (They may still add the mana and thus become able to pay it if they like.)

This situation is rare since mana payments aren't designed into mandatory costs, but could occur due to cost increases. An instruction to cast a spell "if able" means that spell's cost is mandatory. Most effects like this provide an alternative cost (including "without paying its mana cost") so that mana payment is not an issue, but cost increases to the spell that do include mana are the most common cause of this situation.

Rules

From the glossary of the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

Cost

An action or payment necessary to take another action or to stop another action from taking place. See rule 118, “Costs.”

From the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

• 118. Costs
  • 118.1. 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.
  • 118.2. 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 rules 601.2f–h.
  • 118.3. A player can’t pay a cost without having 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.”
    • 118.3a 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.
    • 118.3b Paying life is done by subtracting the indicated amount of life from a player’s life total. (Players can always pay 0 life.)
    • 118.3c Activating mana abilities is not mandatory, even if paying a cost is.

      Example: A player controls Lodestone Golem, which says “Nonartifact spells cost {1} more to cast.” Another player removes the last time counter from a suspended sorcery card. That player must cast that spell if able, but doing so costs {1}. The player is forced to pay that cost if enough mana is in their mana pool, but the player isn’t forced to activate a mana ability to produce that mana. If they don’t, the card simply remains exiled.

  • 118.4. Some costs include an {X} or an X. See rule 107.3.
  • 118.5. 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 they are paying it. Even though such a cost requires no resources, it’s not automatically paid.
    • 118.5a 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}.
  • 118.6. Some objects have no mana cost. This represents an unpayable cost. An ability can also have an unpayable cost if its cost is based on the mana cost of an object 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.
    • 118.6a 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.
  • 118.7. 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’s considered to be {0}. Paying a cost changed or reduced by an effect counts as paying the original cost.
    • 118.7a Effects that reduce a cost by an amount of generic mana affect only the generic mana component of that cost. They can’t affect the colored or colorless mana components of that cost.
    • 118.7b If a cost is reduced by an amount of colored or colorless mana, but the cost doesn’t require mana of that type, the cost is reduced by that amount of generic mana.
    • 118.7c If a cost is reduced by an amount of colored mana that exceeds its mana component of that color, the cost’s mana component of that color is reduced to nothing and the cost’s generic mana component is reduced by the difference.
    • 118.7d If a cost is reduced by an amount of colorless mana that exceeds its colorless mana component, the cost’s colorless mana component is reduced to nothing and the cost’s generic mana component is reduced by the difference.
    • 118.7e If a cost is 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 601.2f). If a colored half is chosen, the cost is reduced by one mana of that color. If a generic half is chosen, the cost is reduced by an amount of generic mana equal to that half’s number.
    • 118.7f If a cost is reduced by an amount of mana represented by a Phyrexian mana symbol, the cost is reduced by one mana of that symbol’s color.
    • 118.7g If a cost is reduced by an amount of mana represented by one or more snow mana symbols, the cost is reduced by that much generic mana.
  • 118.8. 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 they pay the spell’s mana cost or the ability’s activation cost. Note that some additional costs are listed in keywords; see rule 702.
    • 118.8a 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 their intentions to pay any or all of those costs as described in rule 601.2b.
    • 118.8b Some additional costs are optional.
    • 118.8c If an effect instructs a player to cast a spell “if able,” and that spell has a mandatory additional cost that includes actions involving cards with a stated quality in a hidden zone, the player isn’t required to cast that spell, even if those cards are present in that zone.
    • 118.8d 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.
  • 118.9. 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.
    • 118.9a Only one alternative cost can be applied to any one spell as it’s being cast. The controller of the spell announces their intentions to pay that cost as described in rule 601.2b.
    • 118.9b Alternative costs are generally optional. An effect that allows you to cast a spell may require a certain alternative cost to be paid.
    • 118.9c 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.
    • 118.9d 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 601.2f.)
  • 118.10. 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.
  • 118.11. 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.

    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.

  • 118.12. Some spells, activated abilities, and triggered abilities read, “[Do something]. If [a player] [does, doesn’t, or can’t], [effect].” Or “[A player] may [do something]. If [that player] [does, doesn’t, or can’t], [effect].” The action [do something] is a cost, paid when the spell or ability resolves. The “If [a player] [does, doesn’t, or can’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.

    Example: You control Standstill, an enchantment that says “When a player casts a spell, sacrifice Standstill. If you do, each of that player’s opponents draws three cards.” A spell is cast, causing Standstill’s ability to trigger. Then an ability is activated that exiles Standstill. When Standstill’s ability resolves, you’re unable to pay the “sacrifice Standstill” cost. No player will draw cards.

    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.

    • 118.12a Some spells, activated abilities, and triggered abilities read, “[Do something] unless [a player does something else].” This means the same thing as “[A player may do something else]. If [that player doesn’t], [do something].”
    • 118.12b Some effects offer a player a choice to search a zone and take additional actions with the cards found in that zone, followed by an “If [a player] does” clause. This clause checks whether the player chose to search, not whether the player took any of the additional actions.
  • 118.13. Some costs contain mana symbols that can be paid in multiple ways. These include hybrid mana symbols and Phyrexian mana symbols.
    • 118.13a If the mana cost of a spell or the activation cost of an activated ability contains a mana symbol that can be paid in multiple ways, the choice of how to pay for that symbol is made as its controller proposes that spell or ability (see rule 601.2b).
    • 118.13b If a cost paid during the resolution of a spell or ability contains a mana symbol that can be paid in multiple ways, the player paying that cost chooses how to pay for that symbol immediately before they pay that cost.
    • 118.13c If the cost associated with a special action contains a mana symbol that can be paid in multiple ways, the player taking the special action chooses how to pay for that symbol immediately before they pay that cost.
  • 118.14. Some effects say that “mana of any type can be spent” to pay a cost. This means that players may spend mana as though it were colorless mana or mana of any color to pay that cost. If that effect also gives a player permission to cast spells, this applies only to mana that player spends to cast spells that way. See rule 609.4b.

From the glossary of the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

Pay

To perform the actions required by a cost. This often means, but is not restricted to, spending resources such as mana or life. See rule 118, “Costs.”

From the glossary of the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

Total Cost

What a player actually has to pay, in practical terms, to cast a spell or activated ability: the mana cost, activation cost, or alternative cost, plus all cost increases (including additional costs) and minus all cost reductions. See rule 601.2f.

From the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

• 601.2f The player determines the total cost of the spell. Usually this is just the mana cost. Some spells have additional or alternative costs. 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 or alternative cost (as determined in rule 601.2b), plus all additional costs and cost increases, and minus all cost reductions. If multiple cost reductions apply, the player may apply them in any order. 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, any effects that directly affect the total cost are applied. Then the resulting total cost becomes “locked in.” If effects would change the total cost after this time, they have no effect.