Each grave dug with a Shovel has a 10% chance to spawn a Ghost, which will be aggressive towards the player. Otherwise, the player has a 10% chance to get an Amulet, Gravedigger Item, Blue Gem, Red Gem, Gears, or Nightmare Fuel. Once dug, the grave will not respawn, and each world has a limited number of them.
Digging a grave takes 4% of the Shovel's durability or 1% if using a Regal Shovel .
Each grave dug causes the player to lose 10 points of Sanity.