Hey everyone.

I need some vet here to give me the nitty gritty info on fighters.

At what rate does damage increase, thaco decrease and proficiency points get gained ??

Damage is related to factors including; the weapon used, proficiency points in the weapon type and weapon style, the effectiveness of critical hits, enemy resistances, and the attacker's strength bonus. Kensais (and the Thief kit; Swashbucklers) also get damage bonuses, and furthermore the Kensai's Kai ability will theoretically deal maximum damage, while the HLA Crticial Strike will make attacks count as critical hits.

Base THAC0 for a Fighter starts as 20 at Level 1 and drops one per level until it hits zero (not including other bonuses including Strength and racial bonuses). A high Dexterity score will also improve THAC0 for ranged weapons.

Fighters begin with four proficiency points at Level 1 and gain an extra point every three Levels.

Do you also want us to explain THACO?

In the second edition rule set for AD&D the lower your Armor Class is the better. THAC0, is an acronym that stands for: "To-Hit-Armor-Class-0". You must 'roll' your THACO or higher, on a twenty-sided die, in order to get a hit on an enemy with an AC 0. If your enemy's AC is higher than 0, the difference is added to your roll, if it's lower than 0, the difference is subtracted from your roll.

For instance, say your THACO is 10 and your are battling an enemy with an AC 5. You must roll a 10, or higher, to hit AC 0, but since his AC is 5, you can roll a 5 and still get a hit. The difference of 5 would be added to your roll of 5, thus reaching your THACO of 10. So, in short, the lower your THACO, the better for you.

As your character progresses in levels their THACO will decrease thus increasing their chances of hitting a lower (better) armor class. In game terms this is basically your character getting better at fighting.

An example: Lothar "the generic fighter" has an AC of -2. and Hzzuk "the evil troll" has a THACO of 12, and a +2 to hit from his strength.

This would calculate out as follows: For Dave the Troll to hit Jay he would have to roll a 12 or better. (THACO of 12 to hit AC0, Jay has an AC-2. Normally, Dave would need a THACO of 14 to hit AC-2 but he has a strength bonus that grants him a +2 bonus to hit so the roll required is reduced by 2 down to 12. Simple right?

SOURCE:
http://www.bioware.com/games/shadows.../faq/?faqID=41

Six of spades guide might be useful, here is a link:
http://www.geocities.com/sixospades/bg/bgguide.htm
also if you are after other tables try:
http://www.planetbaldursgate.com/bg2