Magic:Isaacs Greater Missile Storm
Level: Sor/Wiz 6
Innate Level: 6
Component(s): V, S
Casting Time: 1 action
Target: Up to twenty creatures
Saving Throw: None
Spell Resistance: Yes
Metamagic: Empower, Maximize, Quicken, Silent, Still
Energy Substitution: No
A number of energy missiles (two per caster level but to a maximum of 40) appear and randomly hit any hostile creature in the area of effect. If there are more creatures than missiles, only the closest targets will be damaged. If there are more missiles than creatures some of the creatures will be hit with multiple missiles (one missile per 4 caster levels but to a maximum of 6 missiles per target). Each missile deals 3d6 points of magical damage.
Analysis: Avlis Isaacs Greater Missile Storm is optimum vs 2 targets (21d6/21d6), a waste on 1 target (21d6), pretty good against 3 (21d6/21d6/18d6). After 3 targets the damage dice decrease rapidly.