Concussive Spell [Metamagic]
Your spells can sometimes knock an opponent down.
Benefit: A concussive spell forces targets to make a Reflex save or be knocked prone. This feat may only be applied to a spell that makes an attack roll to hit a target or that calls for a Reflex save for half damage. For spells that already require a Reflex save, targets who fail the save for half damage are also knocked prone; the target makes one save for both effects.
For spells that may target one target multiple times in a single round, only one Reflex save is required to avoid being knocked prone no matter how many times that target is struck.
A concussive spell uses up a spell slot one level higher than the spell’s actual level.
Special: Although magic missile does not require an attack roll or a Reflex save, it may also be enhanced with this feat.