Questions on TWF and turning standard attacks into full at..

I feel sure that this must be covered somewhere in the rules, but I
can't find it in the SRD or in the FAQ, so I'm bringing the question
here.

By the rules, if you're already within melee range of a foe, you can
make a melee attack as a standard action, see how it turns out, and
then decide to turn it into a full attack (a full-round action), in
which you get any extra attacks you can make. What happens if the
decision to make a full attack changes the modifiers that should apply
to the initial attack?

This would seem to be the case for a TWF fighter. The rules for TWF
penalties seem to assume that if you have two weapons in your hand,
the normal case is for you to announce a full attack right up front
and apply a penalty to all the attacks you get. But if you don't
decide to make a full attack until the initial attack is resolved,
what do you do? Would you apply the TWF penalty retroactively to the
first attack, which could change its outcome?

Would your answer change if the off-hand weapon is a shield, wielded
by a sword-and-board fighter who normally doesn't go for the shield
bash, but decides to on this occasion?

Thanks,
Iss

On Mon, 22 Oct 2007 11:38:03 -0700, Issachar44 <Issachar44.RemoveThis@gmail.com>
wrote:

>I feel sure that this must be covered somewhere in the rules, but I
>can't find it in the SRD or in the FAQ, so I'm bringing the question
>here.
>
>By the rules, if you're already within melee range of a foe, you can
>make a melee attack as a standard action, see how it turns out, and
>then decide to turn it into a full attack (a full-round action), in
>which you get any extra attacks you can make. What happens if the
>decision to make a full attack changes the modifiers that should apply
>to the initial attack?
>
>This would seem to be the case for a TWF fighter. The rules for TWF
>penalties seem to assume that if you have two weapons in your hand,
>the normal case is for you to announce a full attack right up front
>and apply a penalty to all the attacks you get. But if you don't
>decide to make a full attack until the initial attack is resolved,
>what do you do? Would you apply the TWF penalty retroactively to the
>first attack, which could change its outcome?
>
>Would your answer change if the off-hand weapon is a shield, wielded
>by a sword-and-board fighter who normally doesn't go for the shield
>bash, but decides to on this occasion?
>
>Thanks,
>Iss

Once you have taken an attack with your primary hand with no penalty
you are not allowed to take attacks with your off hand for the rest of
that round. You've "made your decision" about offhand attacks at that
point and can't change it. You could still decide to go into a full
attack sequence with your main weapon (assuming your BAB allows
multiple attacks), but you can't make an attack with the offhand
weapon.

The answer doesn't change no matter what offhand weapon is involved.
By taking that first attack at no penalty you have forfeited the right
to make offhand attacks for the rest of the round.