AC questions

[free_fall]

I'm a little confused regarding AC.

As an example, I have a large shield +1. It has a base AC of +2, an armor check of -2 and an AC enhancement bonus of +1. Equipping this shield gives me an AC of, say, 21.

I tried buying a small shield +2 (base AC +1, armor check -1, AC bonus +2), thinking it would raise my AC to 22 but it didn't. Buying a large shiled +2 *did* raise it to 22.

Oh, wait, I think I see the answer - it's the base + the bonus, right? So, a base 2 + bonus 1 would be the same as a base 1 + bonus 2. And the only reason to switch to the small shield would be to shave 9 lbs. off my weight.

But then there's the armor check - what the heck is that? Is a lower or higher (or, since it's a negative value, perhaps I should say smaller or larger) number better? Would the small +2 be as effective as the large +1?

My PC is a ranger, BTW. TIA.

[Datt]

Yes a small shield +2 and a large shield +1 have the same equivalent AC.

The armor check penalty applies to certain skills like hide, move silently and Listen. It lowers those skills by the number shown.
I am not sure if shields have Spell Failure or not but of course the lower number there the better.

[Mathurin]

Yes shields have arcane spell failure, but since hes a ranger it doesnt affect him. As for the check penalty lower is always better and the smaller the shield the lower the penalty.