The Storm of Insurrection
Casting Offensively means you focus to make your spell even more potent. If you cast offensively, you cannot cast defensively. When you succeed, you choose to gain 1 of the following 3 benefits:
Option 1: Increase your caster level for this spell by 2 levels
Option 2: Increase the DC for any saves versus this spell by 1
Option 3: The spell’s damage is increased 1 for each point you exceed the Concentration DC.
Clarification of Option 3: For spells with duration of multiple rounds, this damage occurs only on the first round, for area spells, this damage affects all creatures in the area, for spells with multiple targets but not an area effect, all the damage occurs only one time to one target, chosen as you would like from among the targets
The DC to cast offensively is Concentration DC 15 + 2 x Spell Level
When you fail to cast offensively, you do not automatically lose the spell. Instead you take 2d12 + Spell Level in damage. You must make an additional Concentration check or lose the spell due to damage (DC 10 + damage dealt + spell level).