Hit probability is determined by comparing two values, offense and defense. These values are each divided into two sub-categories, physical and spiritual. Every player has a base value of 1000 for each of them. These values can be increased by equipping armor, ornaments, and weapons. Some abilities will also modify these values temporarily. A player can see his current offense and defense values in the journal window.
These values determine the likelihood of successfully performing an ability against an enemy player. This is done using a simple equation which compares the attacker's offense value against the target's defense value. The quotient, i.e. attacker's offense divided by (÷) target's defense, can then be applied to the following tables to determine the likelihood of successfully performing an ability against an enemy player.
Here is the equation for determining the quotient:
Quotient = Attacker's Offense / Target's Defense
Players with identical values, e.g. 1000 offense vs 1000 defense, will have an 88.57% chance to hit. Notice that the quotient for values above 88.57% hit probability (i.e. identical values) have much less effect on the hit probability than the quotient for values below 88.57%.