A shovel digs
When you give your players a magic shovel, you shouldn't have to tell them what it does. It's primary function is not to hit monsters with. It's primary function is to dig. When they dig with it, your players should get immediate feedback.
It digs(!):
- deep
- fast
- portals
- rainbows
- oil fountains
- water wells
- dirt automatons
- swarms of bugs
- hidden treasure
- hidden bodies
- secrets
- lava
- mud fountains
- dungeon entrances
- moats
- ankhegs
- quick mud
- land sharks
- purple worms
- pocket pits