A system that picks various specific acts and labels them as "encouraged" or "discouraged" by specific deities. Do things they like and they'll make good things more likely to occur, do things that anger them and they'll make bad things more likely to occur.

For example: Build a nice shrine to a weather god and leave it offerings? Your dwarves are less likely to get rained on. Kill an animal that is "sacred" to a cave god? Forgotten Beast occurrences become a little more likely.

This system would encourage players to incorporate religious customs into their fortress, like having all your dwarves wear a specific type of hat, or forbidding a certain type of beer.