Quick queries regarding use of Multiple Arms and how they interact with other situations:

1) How does handed-ness work with multiple arms? Would you say that if they are right/left handed, that any hand on the right hand side can be used as the dominant hand or would it only be the first hand? Essentially if I am right handed, I lose that arm. Do I still suffer the penalty since it isnt the dominant or do I get to use the other on that side as if it were the same?

2) Someone clarify for me how multiple arms works in terms of ballistic skills and the following situations:

- I have four arms and a bolt pistol in each of them. Do I get to make four semi-auto rolls? The errata suggests that each armed hand counts as a separate roll.

- Building on the above, if so, could I wield two weapons requiring two hands? One in one pair and one in the other? Twin Bolters...ouch.

What be common thoughts on these?

One dominant hand, still. Probably what was the original dominant hand. Will not change if dismembered either. But then again Ambidextrous is a pretty cheap talent.

And yes... Four bolt pistols would equal four separate attacks.

And yes, two 2-handed weapons could also be wielded. Or hell, 4 Basic class weapons if you have recoil-compensation in some form or if they are modded with Pistol Grips.

My character has the multiple arms trait; I happen to have 4 arms - exactly the situation you're asking about.

As for handedness, it looked at the time we were examining rules that it would still apply, but it was vague enough as there may be some loophole, so in order to save on headaches I just took the Ambidextrous Talent (or whatever it's called).

As we've been playing it, we have been allowing any combination you could normally do with two hands and then doubling it. So if you could hold two pistols with two hands, your additional hands are not considered vestigial; you can hold an additional two pistols (and the like) or a two-handed weapon, etc.

Since I gained two additional limbs, I've modified them extensively; one is loaded with cybernetics for surgery and torture, as well as drug-administration - I typically clamp a shield to that hand/arm. The other limb transformed into a flamer-maw; I got the Tzeentch-specific, "reroll all your gifts/mutations" "reward", and ended up with a flamer-arm. Not that I'm complaining - I like it, but I had bloody beautiful wings before :S

Finally, I use a Long-Las with my remaining arms; because I'm not some super-shooter I don't have a ton of talents that would allow me to use multiple guns effectively, but I am certainly well-equipped for combat at any range without even a moment's notice.

I just have a final thought on this situation though; the rules are reasonably clear about wielding multiple pistols and using them, but as far as I can tell, they don't account for "dual-wielding" weapons like heavy-bolters, meaning that you're most likely better off just using one heavy weapon, unless your GM would be willing to count your weapon as twin-linked, which is typically the case when two of the same weapon is fired simultaneously.

There's also the bracing mechanic to consider (unless you add suspensors etc.), when you add an extra heavy weapon into the mix, would it be 2x half actions, i.e. a Full Action to brace?

Personally I'd prefer to keep it simple and let a four-armed PC use 1 heavy weapon, and any combination of 2 one-handed weapons.

Heavy Weapons are generally huge, and even somewhat problematic for an astartes to use... Two of em, would be kinda silly.