Casting on the Defence / Combat Casting question

zlorf · Oct 7, 2005

Hi,

If im a wizard, can i Cast on the Defensive (+4 bonus to concentration if I have combat casting) against a readied action, ie Someone readying to attack me with a bow or another wizard readying a fireball.

Casting on the Defensive: You may attempt to cast a spell while paying attention to threats and avoiding blows...etc PAGE 140 PHB

I understand the Cast on the Defensive is mainly used to avoid AoO, but im wondering if it
can be used in the above situations, after all when someone has a arrow pointed at you, i would see that as a threat.

I also understand that I would have to make 2 concentration checks, first to cast the spell while on the defensive which would be fairly easy for most low level spells and then another against the possible damage + 10 against a arrow or fireball, but at least now I get +4 to my concentration check to cast my spell if that is what I was planning to do.

TIA
Zlorf

Patryn of Elvenshae · Oct 7, 2005

No, you can't cast on the defensive against a readied action. You can choose to cast defensively when you begin your spell, but once you've made that decision, that's it: Casting on the Defensive no longer applies.

As an aside, try out the Skill Focus (Concentration) feat. It gives you a +3 bonus to all Concentration checks (including those against readied actions!) instead of Combat Casting's +4 on the Defensive only. It's more bang for the buck, as they say.

Li Shenron · Oct 7, 2005

What would be the purpose of casting on the defensive in your case?

Casting defensively doesn't provoke an AoO, what does that have to do with the readied attack? It certainly won't let you avoid that, since it is not an AoO.

If you cast def. in this case, you're making a concentration check for no benefit.

Patryn of Elvenshae · Oct 7, 2005

The benefit would be, I believe, the extra +4 bonus on his Concentration roll to beat a DC of 10 + Spell Level + Damage Dealt.

zlorf · Oct 7, 2005

Casting on the Defensive.

Yes thats the reason, but isnt the concentration check DC 10+Damage Dealt as stated on page 70 PHB, 1st line on the Concentration DC table?

Patryn of Elvenshae said:
The benefit would be, I believe, the extra +4 bonus on his Concentration roll to beat a DC of 10 + Spell Level + Damage Dealt.

Zlorf

Patryn of Elvenshae · Oct 7, 2005

Check the footnote.

SRD said:
1 If you are trying to cast, concentrate on, or direct a spell when the distraction occurs, add the level of the spell to the indicated DC.

zlorf · Oct 7, 2005

Cast on the defensive

Ah, the footnote..got it.

Zlorf

Patryn of Elvenshae said:
Check the footnote.

Infiniti2000 · Oct 7, 2005

Li Shenron said:
What would be the purpose of casting on the defensive in your case?

He didn't mention the invisible enemy rogue nearby.

zlorf · Oct 7, 2005

Cast on the Defensive

Infiniti2000 said:
He didn't mention the invisible enemy rogue nearby.

Good point, if i knew there is an invisible rogue in the area with a crossbow ready to strike, why cant i cast say "see invisibility" so i can see where the rogue might be and if i used cast on the defensive, if would have to make a concentration check of 15+2=17, which is pretty simple for a mage with maxed concentration. When the rogue shoots his crossbow and hit, i now get the +4. I see nothing wrong with this!

Zlorf

Infiniti2000 · Oct 7, 2005

There is nothing wrong with it. If you can automatically make the cast on the defensive check, you should always use it so that your combat casting is active.