To-hit

Contents:
  1. Example 1
  2. Example 2

With each attack, calculations ensue to determine whether or not you can land one or more hits. To do this, there are three factors at play: weapon plus-to-hit (PTH), weapon base chance to hit, and the Dexterity (DX) modifier. Remember that various things can reduce your effective DX or PTH. All calculations represented are based on your effective values (ie, after all effects/bonuses such as Evasion or ranged penalties are calculated).

  • First there is the weapon PTH. This is exceedingly easy. Each plus on the weapon adds 1% to your total chance to hit (CTH). Keep in mind that each plus on Displacement Boots and each point of Evasion will subtract one from your PTH (and thus subtract 1% from your CTH). For purposes of the following equations, PTH will be shortened to just P.

  • Next, there is the CTH due to DX. This is found in two stages. First, there is the ratio of your DX to your attacker's effective defensive DX (Call this value "D" for the "DX CTH"). Then there is further modification based on your weapon type (see below). Call this second, intermediate value "H" for the base hit chance due to the handed-ness of the weapon. D is capped at 100% + H, and H may change throughout the attack.

  • The penalties or bonuses associated with the weapon (H) are based on its type, either 1-handed (1H) or 2-handed (2H). Every weapon has a base chance to hit (CTH) of 50% modified by adding a third or subtracting a third depending on the weapon class. Once you get to your third attempt at hitting (triple hits and above), the bonus or penalty goes away and you're left with the base of 50%. The following shows the three possibilities for the value of "H":

[Ed. note: From testing with GL and Nerevas we think that its possible that 2H CTH is 37.5%. Someone should verify this.]

 First two hits:
 1H: H = 50% * 1.333 = 66%
 2H: H = 50% * 0.667 = 33%

 Hits 3+:
 1H and 2H: H = 50%

The equation for 'D' is then:

 D = Attacker DX / Defender DX * H
  • This might require an example. Say you use a one-handed weapon with a DX of 2,500 and you attack someone with a DX of 250. Your ratio of 2,500/250 is 10, and 10 * H is 10 * 66% is 660%. This is capped, however, at 100% + H, or 166%. So, your final value for D is 166%. Switching the DX values (250 DX vs 2,500 DX) yields a ratio of 0.1, and 0.1 * 66% is 6.6%. CB rounds everything up, so your value for D is 7%.
  • This means that an attacker's CTH from DX is maximized when the Attacker to defender DX ratio is 3 at a 50% base (1.50 / 0.50). When the base is 66% or 33%, the ratio hits max at 2.51 and 4.03 respectively (1.66 / 0.66 and 1.33 / 0.33). A defender can likewise minimize an attacker's DX-based CTH (ie, reduce it to zero) when the Defender to Attacker ratio is 1.25, 1.65, or 0.825 for a 50%, 66%, or 33% attacker's base CTH, respectively (1 /(0.4 / base))
  • Finally, there are penalties applied that grow with each hit. Subsequent hits become increasingly hard to conduct, as with every subsequent hit, a -100% is applied to your total CTH. Call this value "R" because we're running out of letters.
  • All of this combines to form your total hit percentage. If it's above 0, add 5 as a little bonus to ensure a minimum chance of 5% instead of 1%, and that determines if you can hit and if you get to keep trying. Everything is added linearly, so given the above terms, you can get: D + P - R + 5. An example will illustrate this better:

Example 1

 * Attacker: 150k DX, a +150 1H weapon
 * Defender: 50k DX, a +130 DB

 H = 66%
 D = 150K/50K * 66% = 198% cap at 166%  (H+100)
 D + P = 166% + (150 - 130) = 186%
 D + P + MAGIC 5% =  186% +5% = 191%
 When H=50 (Hits 3+): D = 150k / 50k * 50% = 150%, capped at 150 (H+100)
 >> D + P + 5% = 150% + 20% + 5% = 175%

 Hit 1 -- 191 - 0   = 191% = hit
 Hit 2 -- 191 - 100 = 91%  = possible hit
 >> H gets reduced <<
 Hit 3 -- 175 - 200 = 0%   = no hit

Example 2

 * Attacker: 150k DX, TOA 1M level (~80% PTH), +40 2H weapon
 * Defender: 50k DX

 H = 33%
 D = 150k/50k * 33% = 99%
 D + P = 99% + (80% + 40%) = 219%
 D + P + Magic 5% = 224%
 When H=50 (Hits 3+): D = 150k / 50k * 50% = 150%, capped at 150 (H+100)
 >> D + P + 5% = 150% + 80% + 40% + 5% = 275%

 Hit 1 -- 224% - 0   = 224% = hit
 Hit 2 -- 224% - 100 = 114% = hit
 >> H gets reduced <<
 Hit 3 -- 275% - 200 = 75% = possible hit
 Hit 4 -- 275% - 300 = 0%   = no hit
    last edited by AdminNightStrike at Sep 25 2007 - Edit To-hit

Pages that link to this page: