Stamina affects skill gain. The less stamina you have at the beginning of an action the more skill you will receive. As long as you have at least 1% stamina at the beginning of the action you will receive skill. If you perform actions at 0% stamina you receive no skill. Action time also affects skill gain. The longer the action, the more skill you gain for that action.
Nutrition also affects skill gain. If you have above Starting at 60% nutrition you gain receive a 1%bonus, this bonus changes continuing at 1% every 10% nutrition up to a 5% bonus at 7099%. Below 40% you receive an inverse 1% penalty every 10% nutrition.
===Family skills===