Casting on the defensive... at 1st level

[MarauderX]

Help me out with something...
Why would a 1st level wizard want to EVER cast on the defensive?
Casting normally gives an AoO on the wizard, and if he is hit must make a concentration DC 10+damage check to complete the spell. Yeah, it gives the attacker a second swing, but if you were the target in the first place, why not take a chance?
Just a refresher, casting on the defensive gives a concentration check of DC 15+spell level.
So because of this, at what level is a wizard going to start to use this 'ability'? My thinking is around 3rd level or so, where the concentration skill is up around 6-10, but what a 1st level mage multiclass? I want to encourage a caster to be a little more risky and try to cast, especially if they have the HP and are only facing low damage critters.

 

[CRGreathouse]

Why would a 1st level wizard want to EVER cast on the defensive?

He felt like it?

He was backed against a wall by a creature who can deal 2d6+3 damage per round?

He can cast cantrips on the defensive automatically*, so why not?

* It's possible...

 

[Silver Griffon]

Why open yourself up to two attacks in a round plus maybe lose your spell when you could just open yourself up to one attack in a round and maybe lose your spell? At 1st level, a wizard that is hit with two melee attacks is a dead or dying wizard. Heck, most 1st level wizards are pretty bad off from one successful melee attack. The highest DC you can face for casting defensively at 1st level is 16. Of course, if you take more than 6 points of damage as a 1st level wizard you're probably incapacitated or dying anyway, so possibly losing the spell then becomes a moot point. Personally, I'd much rather take the DC 16 and lose a 1st level spell than risk an extra attack that could cause me to lose the spell anyway and suffer damage (maybe twice!). Especially since most melee weapons can potentially deal more hit points in a single blow than a 1st level wizard usually has. And as you gain levels, this becomes even more true. The casting defensively DC is almost always easier than the DC if you are actually hit (unless the attacker rolls a 1 or a 2 for damage). And your concentration skill should always be able to handle most casting defensively checks if you max it out at every level. The Combat Casting feat makes it a no-brainer. Unless he has an AC at least in the high 20s, every wizard should always cast every spell defensively whenever he is threatened.

 

[MarauderX]

Yeah, perhaps I didn't really word it well, but I understand the 1st level wizard thing, but what I was wondering about is multiclass like a 1st level wizard/2 level (insert other class here) who has about 0 concentration and didn't take the combat casting feat. The character has the HP to take a hit, so why not? The DC would most likely be close to the same or less IF he got hit while casting, which happens to be less risky at the lower level than taking the auto defensive casting. Say a goblin attacker has to hit AC 13 before the caster has to even take the concentration roll. The PC gets to make the goblin try to hit him first, then if it does, he still gets to make a concentration check. The added logic is that even if the damage the goblin did was high, the PC would most likely have a lower DC than the Casting on the Defensive(minimum DC 16).

 

[Silver Griffon]

Yeah, perhaps I didn't really word it well, but I understand the 1st level wizard thing, but what I was wondering about is multiclass like a 1st level wizard/2 level (insert other class here) who has about 0 concentration and didn't take the combat casting feat.

Ah. That changes everything. If its a 3rd level character with 1 level of wizard, then you are correct. In fact, if he has mobility then he's better off deliberately moving in such a way to provoke an AoO from the creature threatening him and then casting the spell. (Just hope the creature doesn't have Combat Reflexes. )