Spell Coupling

Extraordinary

Level11

When you cast an instantaneous spell that deals damage, you can expend an additional unused spell slot to code additional magic energy onto the spell, bolstering its effectiveness. You gain a bonus to your attack roll with the spell equal to half the additional unused spell slot’s level. The spell deals an additional 1d6 damage for every level of the additional unused spell slot. The saving throw DC of the spell increases by 1 if the additional unused spell slot expended is 3rd, 4th, or 5th level, or by 2 if you expended a 6th-level spell slot.

These benefits apply to all creatures affected by an area spell, but for spells that target multiple creatures with multiple rays or other attacks (such as magic missile), the increased damage applies only to a single ray or missile. This increased damage doesn’t apply to ongoing damage from the spell (such as bleed or burn), nor does it increase ability damage or the spell’s other effects.