The tests in the game are resolved with D20 rolls and all tests need 12 or more to succeed (with exception). Other sizes of dice come into play mostly when scoring damage with weapons. It's an easy system to grasp; it worked in Forbidden Psalm and it doesn't suffer any from being cast into a world where firearms exist.
12 graves topped with d4s are arrayed into 3 neat rows. Two groups of hunters are advancing on them.