Sanity

Someone replace this with that "make a san check pls? just a little one" adorable octopus picture thing.

Sanity, in roleplaying games, is a measure of how mentally stable a character is. In traditional roleplaying games, such as AD&D, a character's mental state was entirely up to how the character's player wished to portray them; however, Call of Cthulhu, based on the Cthulhu Mythos by writer H.P. Lovecraft, features the progression to insanity as a major feature of the setting and gameplay, and introduced the Sanity attribute to track the character's descent into madness. The concept proved extremely popular, and has since been modified and incorporated into a wide variety of different RPGs, either as a core part of the system or as an optional rule for gamers running horror-based campaigns.