casting defensively

[Mhart7707]

Ok so I'm a little confused about casting defensively with my blade bound magus. What I'm confused about is how much of a penalty to hit I take when I use his spell combat skill so far I have managed to avoid using it but now as I approach lvl 12 I find that I need it more and more. So how much of a neg do I take when casting defensively?

[Gauss]

You decide the amount of the penalty to attack (up to your Intelligence bonus) and add the same number to your concentration check.

So, if your intelligence bonus is a +3 you can do -1attack/+1concentration, -2attack/+2concentration, or a -3attack/+3concentration.

At 8th level you get an extra +2 bonus to your concentration check (for no penalty).
At 14th level the bonus you get is doubled (-1attack= +2concentration and so on).

[Mhart7707]

Yes buy fighting defensively by itself causes negs do I apply those as well or does the magus ignore that?

[Mhart7707]

Plus if I use spell combat I tale a -2 to attack is that also in play do ideally I can take a neg 5 just to use spell combat defensively....
Is that right

[Gauss]

Fighting Defensively is not the same as Casting Defensively. They are two separate things.

Casting Defensively: You avoid an AoO due to spellcasting. Make a concentration check to successfully cast a spell.

Fighting Defensively: Take a -4 attack penalty and gain a +2 dodge bonus to your AC.

If you are using Spell Combat and Casting Defensively and you take a -3attack penalty for casting defensively then you have a -5 attack penalty and a +3 bonus (+5 at level 8) to casting defensively.

If you are also fighting defensively then you take an additional -4 attack penalty and gain a +2 AC bonus.

I think you may be confusing separate things. What you have here is multiple penalties from different sources. Since penalties stack they all apply.

[Mhart7707]

Oh ok I see now

[TGMaxMaxer]

You should have a +12 from level, at least a 18 int by this level for a +4, and a free +2 from casting during spell combat. That gives you a +18 on concentration checks. even on a roll of 1, that succeeds for 1st and 2nd level spells. They don't auto fail on a 1.

I would buy some Spellguard Bracers (5k, +2 concentration, 3/day roll twice on a concentration and take the higher) to get you to a 21 even on a 1, which means 3rd levels spells are auto success.

If you do need to cast a 4th level spell in close combat, then you can use the bracers to roll twice, or take a -2 to hit (on top of the normal spell combat -2) to make sure you don't mess up.

once you hit 10th level a magus should never have to worry about concentration checks from casting defensively, unless you have very low Int.

[Mhart7707]

So I casting defensively a standard action by itself or can I just say "I attack monster x and cast this spell defensively." Or do I need to do it a certain way

[TGMaxMaxer]

You decide to cast defensively whenever you cast a spell as a free action as part of casting, you roll concentration.

[Mhart7707]

Oh that is amazing thank you so much