Dispel Magic (Sp): You can dispel magic by making a Mastery check against a DC of 11 + the caster level of the effect you are trying to dispel. The Mastery rating you add to this roll is your Mastery in the school of the effect to be dispelled (so if you are dispelling a charm person, you'd add your enchantment mastery).

Dispelling magic is standard action. You can dispel only one spell or spell-like ability at a time. If you know that an opponent has a certain spell/method in operation on them, you can target it directly ("I attempt to dispel the alter mind he's under"). If you know only generally what spells he has ("some kind of protective ward") you can specify a school of spell and attempt to dispel that school. The lowest level/mastery spell of that type currently running on the target is affected by your dispel. If the target is not under any magical effects from that school, your dispel attempt has no effect.

You may choose to 'empower' your dispel effect by spending mana. The amount of mana you spend cannot exceed your mastery in the school of the spell to be dispelled. Each point of mana you spend grants you a +2 bonus on the dispel check. You must make a channelling check for using this mana, as if casting a spell of this school. If you fail the check, you lose the mana you spent and automatically fail the dispel check this round.