Self-Control Rolls
In circumstances that are likely to trigger your problem, you may opt to roll 3d against your self-control number to see whether your disadvantage actually affects you. If you roll less than or equal to this number, you resist your disadvantage – this time. Otherwise, you suffer the listed effects. This is called a self-control roll. Like all success rolls, self-control rolls are subject to modifiers.
Exceptionally mild or severe stimuli can give bonuses or penalties. Drugs and afflictions can make you more or less likely to give in. Other disadvantages can make you irritable, reducing your odds of resisting. See the disadvantage descriptions for details.
Example: Your self-control number is 15, but you are in a highly stressful situation that gives -5 to your self-control roll. You must roll 10 or less to resist your disadvantage.
You never have to try a self-control roll – you can always give in willingly, and it is good roleplaying to do so. However, there will be times when you really need to resist your urges, and that is what the roll is for. Be aware that if you attempt self-control rolls too often, the GM may penalize you for bad roleplaying by awarding you fewer earned points.
Optionally, the GM may permit you to use one unspent character point to "buy" an automatic success on a self-control roll. Points spent this way are gone for good, but there will be times when staying on the straight and narrow is worth the sacrifice. In this case, the GM should not penalize you for bad roleplaying, because you are penalizing yourself!
Note that high Will helps you make Fright Checks and resist supernatural emotion control, but it does not improve self-control rolls – not even for disadvantages with effects identical to these things. Mental disadvantages represent an aspect of your personality that you cannot simply will (or reason) away. This is part of what makes them disadvantages!