This is a description of a proposed statistic that is calculated for monsters (and potentially players). It could eventually be used to compute a monster's actual level and experience reward.

Goal: Two monsters (or a player and monster) with the same combat level should have an equal chance of winning (killing the other) in combat.

Since this is hard, let's start with just standard melee combat.

Two monsters A and B are fighting each other in melee combat. They have an equal chance of winning if the mean time taken for B to kill A (ta) is the same as the mean time taken for A to kill B (tb).

To calculate ta:

• B's base damage per tick: damage_b × speed_b
• B's chance to hit: p_ba = 1 – 0.05(WC_b – AC_a) (clamped between 0.05-1)
• A's health regeneration per tick: r_a = CON_a / 4
• Net damage taken by A: nd_a = p_ba × damage_b × speed_b - r_a
• Ticks to die: ta = HP_a / nd_a

Expand: ta = HP_a / \((1 – 0.05(WC_b – AC_a)\) × damage_b × speed_b - CON_a / 4)

Flip all the a's to b's and b's to a's to get the vice versa.

Let us arbitrarily define a combat level difference of 5 levels to mean that when A kills B, A still has half their HP left. That means ta / tb = 2. So the formula for computing a relative combat level difference between two monsters is:

5 log₂ (ta / tb)