Spell Combat

At 1st level, a magus learns to cast spells and wield his weapons at the same time. This functions much like two-weapon fighting, but the off-hand weapon is a spell that is being cast. To use this ability, the magus must have one hand free, while wielding a light or one-handed melee weapon in the other hand. As a full-round action, he can make all of his attacks with his melee weapon at a –2 penalty and can also cast any spell from the magus spell list with a casting time of 1 standard action (any attack roll made as part of this spell also takes this penalty).