In any situation that the GM feels is stressful, he will roll 3d. On a 6 or less, you have a flashback. The GM will roll whenever you miss a Fright Check or make the roll exactly, and whenever you fail a self-control roll for another stress-related disadvantage.
Make a self-control roll each morning upon awakening. If you fail, you suffered nightmares; this costs you 1 FP that you can only recover through sleep. On a roll of 17 or 18, you are left shaking, and are at -1 to all skill and Perception rolls for the entire day.