Damage explanation please

Two little questions i got for u guys.
How do u calculate the damage made by a weapon?
For example, a bastard sword does 2D4 damage, or a katana 1D10 ...
The Question is ... what does those number mean and how do u calculate the damage done by them ?
Second is
what is the meaning of the speed factor of a weapon ?

Hmm.. a little stupid but .. that's it. A man's gotta do what a man's gotta do ... and i must know this .. so ...
Thx already.

[Memnoch]

This is how it works:

2 - no of dice the computer rolls
D
4 - type of dice eg 4 is a 4-sided dice

So 2d4 means 2 x 4-sided dice. So the total would be 2-8 points of damage. Correspondingly 1d10 would be one 10-sided dice so the damage range would be 1-10.

All damage modifiers due to strength, weapon enchantments etc are added after this total is arrived at.

Speed factor is how quickly the weapon can be wielded in combat. So the lower the number is the more quickly you can bring it into play. A round in BG2 is approximately 10 seconds, so a weapon with a speed factor of 2 can be brought in play in the 2nd second.

Additionally, you gain some bonus or malus depending of your weapon proficiency, check the info window when creating a character for more details. Finally, you can make 'Critical Hits', that is, you throw a 20 on a D20 (almost all attacks are calculated on a D20). Throwing a crit like this makes your screen shake (if you haven't turned this feature off) and does twice the usual amount of damage.

Some for dices: The difference between 1D8 and 2D4 are the possibilitys. With an 1D8 you have equal chances to threw a 1, 2, 3 ... with 2D4, you throw at min. 2 (2 x 1), but over many threws with 2D4, you get an average of 5, compared to the 1D8 where you get an average of 4.5, so 2D4 is usually better then 1D8. The same way works with 1D12 or 2D6.