Hitradius

hitradius <radius> <1> <2> <3> <4>

This inflicts damage to actors within the distance <radius> from the centerpoint. The damage is split into four sections, <1> being the section furthest from the center, <4> being the section closest to the center.

You can put ifhitweapon { ifwasweapon RADIUSEXPLOSION { <effect(s)> } } into actor code to detect when a hitradius has been spawned.