Casting Spells

We have no business calling in such things from outside, and only very wicked people and very wicked cults ever try to.

—H. P. Lovecraft, The Dunwich Horror

Manipulating the forces of the Cthulhu Mythos leads to a loss of Sanity points in amounts that vary by spell. If some awful creature arrives in response to a spell, encountering it costs yet more Sanity points. Having no Sanity points does not prohibit spells from being cast—if it did, there would be no cultists.

Nearly all spells and many magical artifacts also require Magic points (or POW, if that is the need), to be expended, otherwise the spell does not activate and nothing happens.

Physical components may be necessary for particular spells. Such components may be reusable; for example, the great menhirs necessary for summoning He Who Is Not to Be Named (Call Hastur). Other components may be consumed during the spell, such as the drinking of space-mead.

The time required to cast a spell is variable—it may be instantaneous, a few seconds, a game minute, a game week, or longer.

The caster must know the spell and recite a sometimes complex and lengthy chant or rite in authoritative tones. Usually the caster must have complete freedom of movement, since gesture can be as important as chant.

A casting roll is required when a character attempts to cast a newly learned spell for the first time. Once a spell has been successfully cast (even if a pushed roll was required to do so), subsequent uses do not require a casting roll; non-player characters and monsters do not need to make casting rolls.

A Hard POW roll is required to successfully cast a spell the first time. If the casting roll is successful, refer to the spell description for the outcome. If the casting roll is failed, nothing happens.

Following a failed casting roll, the character has a choice whether to make a second attempt to cast the spell (paying the costs a second time)—either immediately or at any time in the future—and, in doing so, push the casting roll. 

If the pushed casting roll is successful, the spell works normally without negative consequences. If the pushed casting roll is failed, the spell still works normally, but dire consequences ensue for the caster. Ultimately a spell can always be cast—the casting roll gauges the harm the caster suffers in the process rather than success or failure of the spell.

The only alternative to this (other than giving up on the spell) is to go back to the source and learn the spell again from scratch—usually requiring another 2D6 weeks and a Hard INT roll. After relearning the spell, another initial casting roll may be made—this is a much more cautious approach than pushing the casting roll. This is one of the reasons why wizards seek to extend their lives—miscasting the greater spells can be a fast route to the grave!