Is there a way to see the code? I've seen references to a time where it was distributed as code. Not sure if it still is somewhere
EDIT: Found the scripts. Feel silly.
Definitely hit chance. The attacker speed (with modifiers) is compared with the target speed. The difference in speed combined with a roll determines if you do a precise, hit, glancing, or miss. From a quick look, if the attacker has 3 more speed than the defender, they have a 99% chance to hit. If they have more than 10 speed, theres a possibility to get the precise hit (30% on the roll, goes up the bigger the speed difference is. Being much slower gives a 25% chance for a glancing blow. No matter how slow you are, you have a 5% chance for a glancing blow.
It also comes into play with capturing enemies.