Eclipse Casting(SU)
When a mystic theurge cast an acane spell, there is a chance he can also cast a divine spell as a swift action in the same turn. When a mystic theurge cast a divine spell, there is a chance he can cast also an arcane spell as a swift action in the same turn.
Once a mystic theuge triggered a swift arcane spell using Eclipse ability, he can no longer trigger another swift arcane spell using this ability until he successfully triggered a swift divine spell.
Once a mystic theuge triggered a swift divine spell using Eclipse ability, he can no longer trigger another swift divine spell using this ability until he successfully triggered an swift arcane spell.
The chance of triggering an eclipse casting is determined by character's mystic theuge level and the triggering spell's spell level. At 1st level, casting a 1st level spell have a 20% chance of triggering a swift spell from the other spell casting school. At 3rd level, casting a 1st level spell have a 40% chance of triggering a swift spell from the other spell casting school. Likewise, at 9th level, casting 1st level spell have 100% chance of triggering a swift spell from the other spell casting school, a 2nd level spell have 80%, a 3rd level spell have 60%, a 4th level spell have 40%, and a 5th level spell have 20% chance of triggering an eclipse casting.
Once triggered, you may choose any spell you have prepared or known regardless of spell level.
Eclipse Casting replaces Combined Spells.