Defense Stat Notes

You will notes a pattern in combat statistics formulas.

Nearly all defensive statistics are base ten. This is to offset the use of a d20 roll on the part of the attacker.
By virtue of the fact that the attacker gets to add 1-20(d20) to his attack value, assuming the attack value of the attacker and the defense value of the defender are equal, the attack value will always be higher:

If A = D
A + 1~20 > D

So by adding 10 to the defending value we can say that the attacker has a 50% average chance of hitting the target:
If A = D
(D + 10) - (A + 1~20) = 9 ~ -10

In the above equation all positive numbers and 0 equal a failed attack and all negative numbers equal a successful attack.

Defense Stat Notes

Lords and Legacy DiceMasterNick