Attack Rating and Chance to Hit Mechanics

Preface
Calculating AR (Attack Rating) is a very simple and straight forward matter. As long as you are mindful of the hard coded AR bug that effects ranged weapon attacks correctly calculating the AR for any of your attacks is simple. The nuts and bolts of the CTH (Chance to Hit) calculation will also be revealed. Then at the end of the article will be reference tables meant for the purpose of saving time from doing calculations. One thing that should be noted about the character screen is that it often lies about the actual AR value for ranged weapon attacks since the character screen fails to recognize the hard coded AR bug.

Weapon Attack AR Calculation

 * 1) Multiply your dexterity soft stat value by 5.
 * 2) Add your your class AR penalty to the result of step 1.
 * 3) If you are an amazon, assassin, druid, necromancer, or sorceress subtract 20
 * 4) If you are a barbarian or paladin subtract 15
 * 5) Add all Flat AR bonuses from gear and states to the result of step 2.
 * 6) Total up the sum of all %AR bonuses from skills, gear, and states and factor it into your total AR score.
 * 7) If attack is a melee attack then increase the flat AR by x% where x is the sum of the %AR.
 * 8) if attack is a ranged attack then treat %AR sum as flat AR and add it to the result.
 * Example : You have 300 base AR from dexterity and 200% AR from an Improved Aim aura. Your normal attack with a sword would have 900 AR for the melee attack while your normal attack with a bow would only have 500 AR.

Chance to Hit Calculation
(chance to hit) = 200% * ([attacker's AR]/[attacker's AR + defender's defense]) * ([attacker's level]/[attacker's level + defender's level])

Since it's a formula with only 4 inputs that are easily calculated it is very easy to create tables to show the various chances to hit that would register depending on the relation of AR to defense and the levels of the two sides involved.