Combine force bolts and digging beams. Specifically:

• Remove the wand of striking and the spell of force bolt.
• Roles that start with force bolt instead start with magic missile and at least 10 maximum Pw.
• All current environment interactions of force bolts (breaking boulders and statues, crashing open doors, etc) are moved to digging beams.
• Make digging beams affect monsters, with a guaranteed hit and fixed 6d12 damage from the spell (since it would be level 5), less damage from a digging wand.

Zapping a wand of digging sideways while you are in a pit creates a line of pits along the floor where it’s zapped. Not specified what happens when the beam hits a wall.

When you engrave with a wand of digging, you engrave it just fine, but you also create and get stuck in a pit on your square.

Using digging to escape from an engulfer no longer leaves it teetering on the brink of death at 1 HP. Instead it cuts the engulfer’s HP in half. For unsolid or amorphous engulfers (e.g. Juiblex), it does even less damage than that. It still lets you escape in all cases though.

Zapping a digging ray upward may either detach a boulder from the ceiling, or several rocks, instead of a single rock. If several rocks are released, each gets a separate damage roll.

Wands of digging kill any monster made of earth instantly.