I'm looking at doing a BG1/TotSC-only run. I want to roll up a fighter/thief. Just wondering am I better off rolling a multi-class or going with dual class like a fighter3/thief x or something along those lines?

In BG1 only go multi-class, because you will spend too much of the game without your primary class, waiting for the secondary to catch up. You won't need the extra levels of Thief for HLAs, so that's not an issue. Dual classing also restricts you to being human.

Hickory you've been the one to answer several of my posts as of late and I just wanted to say thanks for that bud. You've been a great help! I'm want to roleplay the character as more of an assassin that backstabs a lot. I was thinking halfling though I know they only get a 17 strength. Is a 17 enough to be an effective backstabber or I should I go with an elf or dwarf so I can get an 18/xx strength?

Hey, I'm only glad to help where I can. :)

As for your character being a backstabber, are you playing vanilla BG1 or do you have access to thief kits with BGT/TuTu? I would say go for Elf, because you will be playing a stealthy game, so the 1 point hit to CON will not hurt you as much, and Elves get bonuses to stealth and have infravision, THAC0 bonuses to bows and large swords, and you can still get that all important 18 STR for your assassin. Go for a Dwarf only if you have kits and intend to go for the Bounty Hunter kit (based on traps).

Personally, I'd go with a Half Elf - you get a little bump to your thieving skills for Race and can have 18s in Str, Dex and Con. That's something none of the three Races you mention, Elf, Dwarf and Halfling, can do [at start anyway].

Half Elves make the best backstabbers, IMO, since they combine all the best stat possibilities with decent thieving skills - not as good as any other non-Human, but with none of the drawbacks of anyone else, either.

If you were interested in a trap-finder, lock-picker, then Halfling is better due to the Racial bonuses, but for a more combat oriented F/Th, I'd go with 1/2 Elf.

ps Yes, Hickory is a font of knowledge and a very helpful poster! Knows the game inside-out apparently, and happy to share. Gotta respect and appreciate that. :)

Actually, Dwarf has the best bonuses for traps, finding and setting, and for open locks (+15/+10/+10 Dwarf vs +5/+0/+5 Halfling). Halflings are best at stealth. Well thank you for that, but honestly I would never claim that I knew the game inside-out (there are folk on these forums with much more knowledge than I). I have a... (cough)... few years experience playing the game is all. But I appreciate the sentiment, nonetheless. :)

I'd suggest Half-Orc if you've got Tutu or Trilogy; yeah, you might not get the DEX and skill bonuses, but 19 STR means you can backstab like a truck.
Also, Hickory, stop being humble. You're awesome. :p

If I went half-orc should I still go with fighter/thief or would a pure thief suffice since his strength is so good?

Having done a ton of reading and research about this, including expert recommendations and reading up about the rules and mechanics.

Basic multi/dual classing info:

Dual class: Huge portion of the game during which it sucks horribly as it transitions very painfully, terribly designed mechanic (blame 2e DnD), very easy to break the character making it worthless without proper research.
Has the potential to produce the strongest characters with very careful min maxing if you know what you are doing.

Single class: Best choice for BG1 characters. In BG2 it is obsoleted by multi-class or a conservatively built dual classes in BG2 (aka, dual class early)

3 class multiclass: Useless without XP uncapper mod. With such a mod it is a viable but very slow progression (read: weaker than any 2 class multiclass choice for the entire game)

2 class multiclass: Somewhat inferior to single class in BG1. Vastly superior to it in BG2. Can't be messed up. No huge period of uselessness as they transform (like dual class has). This is always viable throughout the game from BG1 to end of BG2. Only thing that compares to it in late BG2 is a very carefully made dual class. Most recommended option.

Recommendation:
For BG1 I recommend: single class fighters, single class theif, single class cleric, multi-cass fighter/mage, and multi class fighter/cleric
For BG2 I recommend: ONLY 2 class multi-class characters. Or carefully done dual classes (eg, imoen can be safely dual classed from thief to mage once she gets all her important thief skills up; but be warned she will not have access to them during transition period)

Myself, I'd go with F/Th for the extra HPs [handy when you appear in the midst of enemies *after* the backstab], the better THAC0 [+4 for hidden/surprise added to a better base THAC0 is, well... better] :) and the ability to specialize in weapons [even "just" two points gives you useful adavantages over someone who can only put one pt in things.

The extra half attack at 7th and 13th Ftr levels is also very nice. Considering that normally you will only be one Th lvl behind a pure Th, the advantages of Multi-Classing seem to more than make up for the slight, nearly ignorable, disadvantage.... IMHO anyway. :)

If you want a back stabber, you also ideally want a character that can get into position for the stab. A Half-Orc has zero bonuses in the Thief class... zero. Your choice on whether to go for a Hulk-like Klutz, or a F/T who can get in there and land that first hit, without getting into grief first. You must also spend a lot of time rolling for that very elusive 19 STR, because without it, your H/O is inferior in every way. You must also go multi-class with H/O.

I was including the thief skill additions for high Dex, but failed to mention that. My bad. [I assume most people max out their Dex for their character, although this isn't universal].

With a Dwarf with a 17 Dex and a Halfling with a 19 Dex, their F/RT is the same [+15% in both cases] and the Halfling is actually the *better* lock picker [Halfling +25%, Dwarf +20%].

Yeah, I concede that. :p

Another consideration may be whether you want your main character to handle all thief duties, or focus on stealth and backstabbing while a henchman focuses on locks and traps.

The Half-Orc thief has more merit if you are dumping all those skill points into Stealth.

You can compare where your Half-Orc (STR 19, DEX 18) might compare to a Halfling (STR 17, DEX 19) thief or fighter thief. (After doing this initially, I went back and added a Human Dual-Class option- fighter, dual to thief after 2nd level, STR 18/91, DEX 18.)

0 xp:

Half-Orc Thief (1): Move/Hide 28%/27%, THAC0 +3, Damage +7
Halfling Thief (1): Move/Hide 50%/50%, THAC0 +1, Damage +1
Halfling F/T (1/1): Move/Hide 50%/50%, THAC0 +2, Damage +3
Human Ftr (1): Move/Hide 0%/0%, THAC0 +3, Damage +7

10,000 xp:
Half-Orc Thief (5): Move/Hide 68%/67%, THAC0 +3, Damage +7
Halfling Thief (5): Move/Hide 90%/90%, THAC0 +1, Damage +1
Halfling F/T (3/4): Move/Hide 80%/80%, THAC0 +2, Damage +3
Human F/T (2/4): Move/Hide 58%/57%, THAC0 +3, Damage +7

42,000 xp:
Half-Orc Thief (7): Move/Hide 88%/87%, THAC0 +3, Damage +7
Halfling Thief (7): Move/Hide 100%/100%, THAC0 +1, Damage +1
Halfling F/T (5/6): Move/Hide 100%/100%, THAC0 +2, Damage +3
Human F/T (2/7): Move/Hide 88%/87%, THAC0 +3, Damage +7

The Half-Orc Thief does not lag that far behind the Halfling Fighter/Thief, has a bit of a THAC0 advantage and has a big damage advantage. The Halfling Fighter/Thief gets an extra 1/2 melee attack per round (which is not an extra backstab), and a full extra attack per round at level 7/7 (128,000 xp), and the Halfling Fighter/Thief can use a shield.

However, comparing the Half-Orc Thief to the Human Dual-Class Fighter-Thief, the Human Dual-Class character looks even better. Going dual-class at level 2 and not holding out for 3, the Human is only 2,000 xp behind the Half-Orc in terms of skills. The Thief level will exceed the Fighter level at the 4,500 xp mark- not that long of a transition to wait for the specialization bonuses and shield.