So, you’ve picked up a hefty, suitable-for-chucking-at-players D30. Perhaps you let your players “supercharge” one roll per session (swapping a d20 for the d30). But you want something more. Consider the following:
The Sword of Shifting Injuriousness
This weapon was meant to be another masterpiece forged in the flames of the famed smiths of Hal-Addad, the Dwarfhome. Instead, an imperfection in the ritual of imbuing it with arcane lethality resulted in the sword doing wildly variable damage.
Upon a successful hit, roll a 1d30 to determine damage type for the sword:
2) 1 point of damage
3) 1d4-1 (minimum 1 damage)
6) 1d6-1 (minimum 1 damage)
This magic item has become a favorite in multiple campaigns, in part I think due to the completely overindulgent amount of dice rolling one gets to do when wielding this weapon.