vital strike and spellcasters

[Valrydus]

So my rogue will be 9th level soon and is a crossbow user (driver archetype for shooting on the move). He is also a bookish rogue (see feat) with a knowledge of magic. He is well aware, with that knowledge and an 18 int, that concentration is a very important aspect of spell casting.

That being said, I enjoy readying actions to shoot when I see casting (sometimes this means I need to make a spell craft to distinguish casting from not casting).

My question is this:

"Since I am almost 9th level I am considering taking vital strike as my feat. I use a light crossbow. What do we all think about the extra D8 damage for the purposes of forcing concentration checks for dealing damage."

The idea would be to hide (invisibility, stealth, etc) and crowd control a caster. This may mean ducking down in my wagon (custom wagon with plenty of add-ons). The idea being to wait for when that caster is about to throw some nasty spell on my teammates (or heal himself for that matter) and bam: 2D8 + 5D6 sneak attack (+1 point blank) + misc. Forcing that concentration check.

Standard DC = 10 + damage dealt + spell level.

So the question is....again....is vital strike worth the extra 4.5 damage (i.e. +4.5 to concentration DC)?

Even without sneak attack the average damage would be: 4.5 (1D8) + 1 (enhancement) + spell level (lvl 9 so assume 4-5th lvl spell). DC would be: 20.... but with vital strike it'd be 25.

This obviously isn't counting deadly aim or anything like that.

What do you all think? Would vital strike be worth it here?

(in other news....it would also come in handy for coup de grace)

[LazarX]

I don't see why not.

[NikolaiJuno]

I don't see why this is a rules question.

[LazarX]

NikolaiJuno wrote:

I don't see why this is a rules question.

It sounds like he's looking for approval of his choice. This question should be in Advice, but maybe he's trying to avoid the thousand and 1 voices who would say his first mistake is playing a rogue. (not that I would be one of them.)

[Valrydus]

Im sorry. I actually had to wonder for a few minutes about whether to post this under advice or rules.

I suppose this is the thought process: "I saw this as a hybrid question. Advice always seemed more about RP and simple build-design. I saw this more as a question about how the rules interact. Its a fair criticism and I understand that it would have been at home in advice as well."

As an ex-post facto validation: Can I assume that the rule does, in fact, work as I have portrayed it? Or is anyone aware of something that gets in the way of 'I see him wiggling his fingers...ergo he is casting.....thus my readied action is triggered' ?

[Avoron]

Seems like it will work just fine. Although I'm not sure what you mean by it coming in handy for a coup de grace. Normally it only applies on an attack action, and a coup de grace is a special full-round action. Is there some rule that I haven't heard of that applies?

[Valrydus]

I managed to completely forget about Coup De Grace's being full round actions without a feat.

Thank you for reminding me.

With a feat it is helpful for coup de grace. Ha.