Counterspell - Revised

You attempt to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 2nd level or lower, its spell fails and has no effect. If it is casting a spell of 3rd level or higher you must make a roll. The roll is equal to 1d12 + 4 + spellcasting ability modifier. The DC equals the enemy's spell save DC. On a success, the creature's spell fails and has no effect.