Sacrifices for Favors
Here's an idea for an optional push-your-luck mechanic in your game: In this world you may sacrifice an object to gain favor with some god (or deity-like entity of your choosing) for some sort of in-game advantage. Example : Offering something small and inconsequential like a potion or small amount of coin might net you the chance to reroll a failure. The object offered is lost whether the roll is a success or failure. Procedure : Once sacrifice is offered, player rolls a d6. A roll of 6 is a success and allows a re-roll of the skill check. Anything else and nothing happens. The God of Hoarding has deemed your offering unworthy to dedicate its time to you. The bigger or more substantial the offering, the higher the likelihood the god will give you the chance to re-roll/add a modifier/whatever to your sacrifice roll. DM decides how many d6's can be rolled to improve the odds of catching the god's favor. Caution : Be careful not to offend the