four handing an large sized bastard sword.

[fel_horfrost]

Out of curiosity would it do any thing like reducing penalties or adding an extra 50% strength per extra hand or power attack bonuses?

[blackbloodtroll]

No.

Beyond the second hand, nothing happens.

[Bandw2]

this is one of the things the rules don't cover when you have more than 2 arms.

[fel_horfrost]

Kinda sad that there is no official stance on it.
Though it's a corner case at best

[Nefreet]

There is an official stance.

It can be found in the Core Rulebook.

A weapon outside the scope of Light, One-Handed, or Two-Handed cannot be wielded, by the rules.

A Large-Sized Bastard Sword is a Two-Handed weapon for someone proficient.

It is unwieldable for someone who isn't.