general

Damage calculation based on Defense and Damage Absorb

by apx629131 May 20262 min readOriginal thread on Discord

Player testing of how Defense and Damage Absorption interact in Kathana, with the inferred formula FD = (ID - (DF x 0.27)) x (1 - DA) and the finding that absorption is applied after defense reduction. Includes the raw test numbers (144 DEF vs 390 DEF at 34% absorb) and a practical note that Defense is better against normal hits while absorption scales with big incoming damage. A follow-up message lists the exact gear and skills used to reach 34% DA.

SUMMARY Every 1 point of Defense reduces incoming damage by approximately 0.27 damage. Damage Absorption (%) is applied after Defense reduction, not before.

Variables ID = Initial Damage DF = Defense DA = Damage Absorption (expressed as a decimal) FD = Final Damage Taken

FORMULA FD = (ID-(DF x 0.27)) x (1-DA)

Damage Absorption items are expensive and often treated as the best defensive investment. Current testing suggests that may be too simple.

This guide is based only on limited character testing. The formula is not official. More data will be added as more levels, monsters, and gear setups are tested.

The test used the same monster, with no visible skill applied. Normal hits were used for comparison.

Current inferred damage flow:

Enemy Hit → Defense Reduction → Damage Absorption → Final Damage Taken

Simple formula:

Final Damage ≈ Damage After Defense × Remaining Damage Percentage

Example: with 34% Damage Absorption, only 66% of the damage after Defense reaches your HP.

Current data:

144 DEF + 34% Absorb = around 123–133 damage 390 DEF + 34% Absorb = around 60–65 damage

That is +246 Defense, reducing damage by around 66 per hit.

Current estimate:

1 Defense ≈ 0.27 less FD 10 Defense ≈ 2.7 less damage 100 Defense ≈ 27 less damage

Since 34% absorption was already active, raw Defense may be closer to 0.40 damage reduction before absorption.

Damage Absorption seems to work after Defense. At around 144 Defense, estimated damage before absorption is about 194:

0% Absorb = ~194 damage 9% Absorb = ~176 damage 19% Absorb = ~157 damage 34% Absorb = ~128 damage

DA works as a percentage filter on the damage left after Defense.

Practical takeaway:

Defense lowers the base hit first. DA reduces what remains. Defense is strong for normal hits. Absorption becomes stronger when enemy damage is high, such as against stronger monsters or bosses.

This guide will be updated as more data is tested. Cheers & Happy Hunting

For the absorption. Am using 3 Varman Grapa parts w/ 3% DA each, the new Kathana Charm with 10% DA and lastly the lvl 3 Banar skill Samate providng 15% DA. did this guide as i was debating on getting the lacking 6% from the 2 missing parts, Armor and Pants. Hopefully, i get to the part where i can do a more complete guide with the complete armor set at 15% DA, full Samate at 25% and lastly the charm with 10%. DA will peak at 50%...and if i get lucky, the Rare shield with 15% more DA. That'd be 65% ^o^.

From the replies

  • pausebreak1811 Jun 2026

    Final damage like seniya(vidya buff) and kila(god skill) applies after damage absorb. I saw it from somewhere.

  • pausebreak1811 Jun 2026+1

    can't remember where I read it in discord. I have an FS with lvl 3 Seniya +240 final damage.I can help you test it if you want.

  • apx629113 Jul 2026

    Just used the ones here in Kathana. i do have the XML file for older versions and it seems they did minimal to no tinkering of most of the game's aspects.