Concentration

When casting a spell there are many ways you can be interrupted. If you cast a spell in a threatened square and an attack of opportunity strikes you, you need to roll concentration. There are a lot of times when concentration is needed, below is a table detailing these in.

Cause for concentration	DC
Struck while casting or concentrating	10 + damage dealt
Mild distraction	15
Major distraction	25
Raging	10 + HD + Spell Level
Intensified Rage	12 + HD + Spell Level
Greater Rage	14 + HD + Spell Level