You may gain skill even failing an action - that depends on skill. For instance, [[lockpicking]] won't raise on failures, but [[carpentry]] will.
Stamina effects skill gain. If you have low or no stamina, you will gain almost no skill. It's recommended to have full stamina when you start an action. Action time also effects skill gain. The longer the action, the more skill you gain for that action.
===Family skills===