After 5 minutes of being Critical, after receiving a Killing Blow, or after Poison or Disease have run their course, a character will die. Upon death, a character’s “soul” will remain with their body for 5 minutes. After this final time period, their soul “moves on.”
At this point, the player must leave a “Blood Mark” (a long strip of red cloth that represents a dead body, with their character name written clearly on it) where they died, along with any in-game items on their person. After this, they must go out of play and find a plot member.
Even death can be overcome, and this state is not necessarily permanent. Do also note, however, that characters cannot come back from the dead more than a handful of times before truly passing on.