Make a self-control roll at the end of any battle. If you fail, roll 3d, add the amount by which you failed your self-control roll, and look up the result on the Fright Check Table.
Make a self-control roll each day. If you fail, you must try to trick a dangerous subject: a skilled warrior, a dangerous monster, a whole group of reasonably competent opponents, etc. If you resist, you get a cumulative -1 per day to your self-control roll until you finally fail a roll!