Okay, so I'm reading that a dual-wielding Fighter/Thief's backstab applies the backstab multiplier only to the faster of the two weapons. Presumably the slower of the two weapons damage is also added, though. (Please advise if this is incorrect.)
(Edit - Note to self: next time before posting something this elaborate take time to test premise in CLUA Console! Reportedly this info about the faster of the two dual-wielded weapons scoring the hit in BG:EE was incorrect. I have not confirmed either way, though. The computer I play BG:EE with is being serviced.)
So if you're seeking to max backstab damage, it looks like you want to find the fastest weapon that does the most damage. (Edit: Reportedly this is not the case.)
For reference sake, here is the BG:EE table for weapons.
Bear in mind that a Thief can only backstab with Club, Dagger, Long Sword, Short Sword, Scimitar, Wakizashi, Ninjato, Katana, and Staff. Staff is of course a two-handed weapon however, so it can't be dual-wielded.
In terms of speed these are the normal weapons:
Speed Factor 2
Dagger
Speed Factor 3
Short Sword
Wakizashi
Speed Factor 4
Club
Ninjato
Katana
Speed Factor 5
Long Sword
Scimitar
and for reference sake here is a reference for the vanilla BG1 weapons, and here is the list of the new content enchanted items in BG:EE (contains spoilers).
Some enchanted weapons are faster than their normal versions:
Dagger of Venom has a speed factor of 0 (rather than 2). THAC0 +3, damage 3-6 with up to 15 additional poison damage (6 poison damage per round).
Longtooth Dagger + 2 has a speed factor of 0 (rather than 2). THAC0 +2, damage 3-8.
Short Sword of Backstabbing +3 has a speed factor of 0 (rather than 3). THAC0 +3, damage 4-9.
The Whistler Short Sword +2 has a speed factor of 1 (rather than 3). THAC0 +2, damage 3-8.
Drizzt's Scimtars +3 both have a speed factor of 2 (rather than 5). THAC0 +3, damage 4-11.
Wakizashi +1 has a speed factor of 2 (rather than 3). THAC0 +1, damage 2-9.
Varscona Long Sword + 2 has a speed factor of 3 (rather than 4). THAC0 +2, damage 3-10.
Katana + 1 has a speed factor of 3 (rather than 4). THAC0 +1, damage 2-11.
Rashad's Talon Scimitar +2 has a speed factor of 3 (rather than 4). THAC0 +2, damage 3-10.
Ninjato + 1 has a speed factor of 3 (rather than 4). THAC0 +1, damage 2-9.
And although the new enchanted clubs aren't faster than normal clubs, here they are for reference sake:
Club +1 has a speed factor of 4. THAC0 +1, damage 2-7.
Night Club +1 has a speed factor of 4. THAC0 +1, damage 2-7,
Mighty Oak +2 has a speed factor of 4. THAC0 +2, damage 3-8.
Anyway, what would your weapons prof choices be for a dual-wielding Fighter/Thief?
(Edit - Note to self: next time before posting something this elaborate take time to test premise in CLUA Console! Reportedly this info about the faster of the two dual-wielded weapons scoring the hit in BG:EE was incorrect. I have not confirmed either way, though. The computer I play BG:EE with is being serviced.)
So if you're seeking to max backstab damage, it looks like you want to find the fastest weapon that does the most damage. (Edit: Reportedly this is not the case.)
For reference sake, here is the BG:EE table for weapons.
Bear in mind that a Thief can only backstab with Club, Dagger, Long Sword, Short Sword, Scimitar, Wakizashi, Ninjato, Katana, and Staff. Staff is of course a two-handed weapon however, so it can't be dual-wielded.
In terms of speed these are the normal weapons:
Speed Factor 2
Dagger
Speed Factor 3
Short Sword
Wakizashi
Speed Factor 4
Club
Ninjato
Katana
Speed Factor 5
Long Sword
Scimitar
and for reference sake here is a reference for the vanilla BG1 weapons, and here is the list of the new content enchanted items in BG:EE (contains spoilers).
Some enchanted weapons are faster than their normal versions:
Dagger of Venom has a speed factor of 0 (rather than 2). THAC0 +3, damage 3-6 with up to 15 additional poison damage (6 poison damage per round).
Longtooth Dagger + 2 has a speed factor of 0 (rather than 2). THAC0 +2, damage 3-8.
Short Sword of Backstabbing +3 has a speed factor of 0 (rather than 3). THAC0 +3, damage 4-9.
The Whistler Short Sword +2 has a speed factor of 1 (rather than 3). THAC0 +2, damage 3-8.
Drizzt's Scimtars +3 both have a speed factor of 2 (rather than 5). THAC0 +3, damage 4-11.
Wakizashi +1 has a speed factor of 2 (rather than 3). THAC0 +1, damage 2-9.
Varscona Long Sword + 2 has a speed factor of 3 (rather than 4). THAC0 +2, damage 3-10.
Katana + 1 has a speed factor of 3 (rather than 4). THAC0 +1, damage 2-11.
Rashad's Talon Scimitar +2 has a speed factor of 3 (rather than 4). THAC0 +2, damage 3-10.
Ninjato + 1 has a speed factor of 3 (rather than 4). THAC0 +1, damage 2-9.
And although the new enchanted clubs aren't faster than normal clubs, here they are for reference sake:
Club +1 has a speed factor of 4. THAC0 +1, damage 2-7.
Night Club +1 has a speed factor of 4. THAC0 +1, damage 2-7,
Mighty Oak +2 has a speed factor of 4. THAC0 +2, damage 3-8.
Anyway, what would your weapons prof choices be for a dual-wielding Fighter/Thief?