Arvalia: Ascension of Man
I stole this system directly from Burning Wheel/Burning Empires.
Instincts are things that you always (or never) do, or really simple if/then triggers. In game, you are always assumed to do/have done the action associated with your instincts, even if you do not mention it. In fact, the only way to not follow your instinct is to specifically state that intent.
Some possible examples:
- I am always armed.
- I always search for traps.
- I never turn my back on an enemy.
- I always confirm my kills.
- If surprised, I drop prone.
For more information and examples of instincts (and beliefs) see Burning Empires pp. 119-121.