A character is normally only allowed to make 1 attack each round, even if he does have a weapon in each hand. The non-attacking weapon may be used as a shielding device (see the table on RMC Arms Law page 14).
I see your point about multiple attacks per round, but AL p19 says the following in the description of using Two One-Handed Weapons:
• The combatant may attack with both weapons in the same round, or
they may attack with only one and use the other for its “shield†bonus versus
melee (see Table 02-04). (In which case use the “One-Handed Weapons with a
Shield†rules above)
• A combatant must direct both their attacks (and parry) against the same target.
So now I'm a little confused.
Simple -- I forgot about that section -- plus you will notice that my answer was not in navy blue -- which means that I was answering as me, not making an official answer (because I didn't read all the possible rules on it before replying).
Anyways, what I said above, regarding initiative and activity percentage remains unchanged. It was the note on page 26 (above the Activity Percentage Table) that caused my earlier comment about only 1 attack action (TWC would be considered to be 1 attack action, and that is why it is listed the way it is on that table).
With two weapon combat I'd resolve the two attack rolls on the single target simultaniously. . .The actions are not "Attack left hand" then "Attack right hand" it's "Attack with both weapons". . .remember that an "attack" is a sequence of moves and swings that add up to one roll, taking 5-10 seconds, not just one swing.
If they resolved seperately, you'd be able to pull the "Full DB first attack" then "Full OB second attack". . .it's a combined, complex action, which requires two rolls, but is only one attack action.
It is 2 separate attack
rolls, but it is considered 1 attack
action on the Activity Percentage Table (RMC Arms Law, pg 26). Your first paragraph suggests 1 single roll for both attacks, and that is incorrect. One of its bullet points specifically says "both attacks" which indicates 2 rolls.
And the section that twh pointed out also specifically says that both OB values are reduced when one parries, and that the parry amounts do not stack. Which makes the situation you postulate in the second paragraph a bit of an impossibility.
From the rules on page 19, yes, you can make multiple attacks in a round so long as you have skill in the weapon(s) for the hand in which it is being used (i.e. you need to learn sword (right hand) and dagger (left hand), and dagger (left hand) is a different skill than dagger (right hand)).
So, if you have an ob of 70 for Short Sword (right hand) and an OB of 30 for Dagger (left hand), your OB for making 2 attacks in a round would be 70 Short Sword and 10 Dagger (-20 for off hand if you had not already applied that modifier -- and for the purposes of this example, we will presume that you hadn't), and you would receive a -5 modifier to your initiative rolls.
If you wanted to put 20 points into DB from parrying. You would then have an OB of 50 Short Sword and -10 Dagger and get a total of 20 points added to DB because the OB-to-DB shift affected both weapons equally -- however there is no rule that says you are limited by the lesser OB (makes a nice house rule though, plus it is how the TWC skill in RM2 and RMFRP works).
So....
To answer the original questions again
1) No, you do not need a special skill, only skill with the weapons, in the hands in which they are to be used (and each hand is a separate skill!!)
2) To Resolve them, refer to Step 3B - and resolve the main attack in the first initiative cycle of step 3b and the second in the second cycle.
3) if using Adrenal Speed or Haste, I recommend treating them as an additional 100% activity (not halving existing activity percentages, and then using extra initiative cycles to resolve the additional actions that are allowed.