Hi, last day i was discussing with GM about new PG.
To be short, he claimed that a Magus when attack with spell combat or/and spellstrike, and he cast defensively MUST also Fight defensively, so every magus that fight in close combat MUST take a -6-6 to attack rolls, i know that fighting defensively and casting defensively are two separate things. Who is right?
So i can still fight with a -2 -2 from spell combat making my 15+2x spell level Check on Concentration like i do.
He may be confusing the choice a Magus has to take a penalty on his "to hit" in order to improve his concentration check:
If he casts this spell defensively, he can decide to take an additional penalty on his attack rolls, up to his Intelligence bonus, and add the same amount as a circumstance bonus on his concentration check. If the check fails, the spell is wasted, but the attacks still take the penalty. A magus can choose to cast the spell first or make the weapon attacks first, but if he has more than one attack, he cannot cast the spell between weapon attacks.
It's an option, not mandatory. And fighting defensively and casting defensively are two different things - neither of which are required. (Though you stand a good chance to lose your spell to an AoO if you don't cast defensively!)
You CAN do both, but there is no requirement anywhere that says you HAVE to do to both.