Cost

Cost is the amount of mana required to cast a spell. Cost can be modified by various effects, e.g. Hamlet. Cost cannot be negative.

Sites have a default cost of zero.

When determining the mana cost of a spell with an X value (e.g. Assorted Animals), X is the actual cost while the spell is on the storyline, and otherwise X is zero.

To calculate the total cost of a spell or ability:

• Start with the mana cost or activation cost. For example, 3 for Bury, or 5 if casting via De Vermis Mysteriis.
• Include any additional costs. For example, discarding a site for Craterize.
• Add anything that increases cost. For example, 2 for Maddening Bells.
• Subtract anything that reduces cost. For example, 1 less for Philosopher's Stone.

Note that if you cast the spell "for free" or "for 0," you do not pay any additional costs at all! For example, Deathspeaker on Death's Door near a Maddening Bells will still pay 0 to use the Deathspeaker's ability. See For Free in the Codex for more details.