Certain gods are very strict about proper Piety levels, and other are rather lax. Most deities will fudge a bit, and take other factors into consideration. Characters with Divine Grace will receive bonuses to Divine Intervention and certain worthy Invocations. It also helps in convincing their deity to accept their soul after death. In any endeavor, the character may pray to their deity for aid.
Prayers do take a little bit of time to perform.
Any character may call for divine intervention. Such an intervention might not be recognized as such. For example, a sailor may call for divine aid to prevent him from drowning in the sea, with the intervention taking the form of a timber drifting by that he can grab hold of. The basic chance of divine intervention is quite low, ten to twenty percent. In addition, Prayer bonuses are added, but the number of PP expended is not limited.