Explosive Crossbow Bolts

1d12 fire damage, the target and each creature in a 10 ft sphere succeeds in a DC 17 Dexterity saving throw or is knocked prone. On a critical failure the damage is dealt to the creature weilding the crossbow which serves as the centerpoint for the concussive sphere. The explosion lets out a thunderous boom audible out to 300 ft.  
Item type
Ammunition