Another possibility is the d20 system which works extremely well for pencil & paper rpgs and is the system used in Neverwinter Nights. The specifications for it can be found at http://www.opengamingfoundation.org/srd.html

-- Exitus Acta Probat --

Here is an idea for calculating damage that I''ve come up with in the past.

Every weapon has a damage factor value to it. It also has a strength threshold value as well. This value is the required strength to get base damage factor. If your char is stronger then this value, then their strength will increase the damage factor. If it is less, then the damage factor will be decreased.

I use this damage factor with a d100 roll system. I determine attack value and defense value. I add the d100 to the attack value and then subtract the defense value. If it is zero or negative, it''s a miss. If it is positive, I multiply that positive value by the damage factor (after it has been weighted by your strength stat) to get the damage done. This system automatically scales damage up and down if you are fighting easy or tough opponents. The actual damage factor value will be dependant on how much health targets have, how much damage you want to be done under given circumstances, etc. Example, when attack and defense values are equal, the attacks will hit every time, but your damage factor value will determine damage done. If it''s set to 1.0, you will do anywhere from 1-100 damage with 50 average. If it''s set to 0.25 you willd do 1-25 damage, with the average around 12. If your attack value is 100 higher then the defense value, all attacks will hit, and the damage done with a 0.25 damage factor will be 25-50 damage.

At this point you can also incorporate a critical hit chance for outcomes over a certain value. What I''ve done in the past is base chance of critical hit on strength stat. I modelled crits similar to NWN in that if your ourcome is over a certain value, then you threaten a critical hit. On a threat I roll another d100 and that is compared to my crit percentage (based on str) to determine if a crit is made. Then I just do 2x or 3x damage.

If you want to get more complicated, you can give weapons different damage factors against different armors. Like a longsword will have a high df against cloth (ie no armor) A good df against leather and reinforced, an ok df against chain, and a not so good df against plate. On the negative side, spells like lightning and shock have a high df against chain and plate, and lower dfs against leathers and no armors. Break your weapons in to categories like crushing, slashing, and piercing and provide different dfs against different armors. Give plate and chain armors some negatives (like chain is weak against piercing and crushing, but strong against slash.) It all depends on how complicated you want to get.