Combat and raids

Combat

Solo fights against slay mobs. Each swing compares an attack score against a defence score, and the damage dealt is what pays combat XP to three skills at once.

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Rules and numbers

1. confirmed Combat XP is paid per point of final damage: the chosen skill (accuracy or strength, per the XP toggle) gets 0.5x, Life 0.2x, and the off-focus secondary (Dodge when accuracy is chosen, Defend when strength is chosen) 0.2x, for 0.9x in total.chosenXP = 0.5*finalDamage; lifeXP = 0.2*finalDamage; secondaryXP = 0.2*finalDamage (COMBAT_XP_CHOSEN_MULTIPLIER, COMBAT_XP_LIFE_MULTIPLIER, COMBAT_XP_SECONDARY_MULTIPLIER)
   Source: Constants.js:866-873
2. confirmed Spirit and Slay XP are flat per kill, set per mob in mobs.json (e.g. Feeble Acid Slime 3 Spirit / 4 Slay, Chaos Furious Slime 220 / 300).
   Source: mobs.json (spiritXPOnKill, slayXPOnKill)
3. confirmed Score: effective level (level + cape + pet + tool + slay + potion) times SKILL_MULT 2 times the spirit modifier, rounded down, plus the gear stat.score = floor(SKILL_MULT * effLevel * spiritMod) + gearStat; SKILL_MULT = 2
   Source: Constants.js:525-545, 588-591
4. confirmed Hit chance is 60% at equal scores and moves 0.3% per point of accuracy-minus-dodge score, clamped to 10-100%; any excess above 100% (up to 50%) raises the minimum damage roll toward max hit.hitChance = clamp(0.10, 1.00, 0.60 + 0.003*(A - D)); overflow = min(0.5, raw - 1); minHit = max(1, floor(overflow*maxHit))
   Source: Constants.js:550-554, 626-638
5. confirmed Max hit is 2 plus a fifth of the strength score; the defender's Defend score cuts damage by 1% per 10 points, capped at 75%, and every hit lands for at least 1.maxHit = 2 + floor(S_atk/5); reduction = min(0.75, floor(S_def/10)/100); finalDamage = max(1, ceil(raw*(1-reduction)))
   Source: Constants.js:556-560, 610-647
6. confirmed Crits start at 5% chance and 120% damage; every crit source (combat pets, capes, combat tool tiers, glyphs, tablets, etc.) adds +0.2% chance and +0.25% damage, and a Chaos combat tool counts as two sources.critChance = (5 + 0.2*sources)/100; critDamagePct = 120 + 0.25*sources; critDamage = max(raw+1, floor(raw*critDamagePct/100))
   Source: Constants.js:772-865, 69
7. confirmed Mobs crit off their own slay level: +0.2% chance and +0.25% damage per slay level, uncapped (an Ancient Lich at slay 99 crits 24.8% for 144.75%).mobCritChance = (5 + 0.2*slayLevel)/100; mobCritDamagePct = 120 + 0.25*slayLevel
   Source: Constants.js:818-852
8. confirmed Vigor shortens the attack interval by 0.25% per vigor point (counting level 0), capped at 50%; swapping equipment triples the next attack cooldown.interval = weaponSpeed * (1 - min(0.5, (vigorScore+1)*0.0025)); EQUIPMENT_SWAP_COOLDOWN_MULTIPLIER = 3
   Source: Constants.js:659-667, 747
9. confirmed Ranged or magic attacks without ammo halve the attack and strength scores; base ammo save chance is 0.penalisedScore = floor(score/2)
   Source: Constants.js:671-678, 760
10. confirmed Gear has a special slot. 20 special families come in T1-T5 and Chaos; most need a weapon or style (Dual Wield and Bloodscent on daggers, Cleave and Execute on axes, Double Shot on ranged, Arc on wands, and so on).
    Source: items.json (slot special)
11. confirmed The Reducer: on a kill, a 30% (T1) to 60% (Chaos) chance that the kill counts as two toward your slay task, still with one loot roll. The Extender: the same chance that the kill does not count, so the task lasts longer on that mob.
    Source: items.json (slay_double, slay_skip); game.js slay_task_special messages
12. confirmed The Extender and The Reducer drop only from treasure chests, at the D1 tool rate: 1/(300 - 20 x chest tier) per loot roll.oneIn = 300 - 20 * chestTier
    Source: Constants (CHEST_SPECIAL_FAMILIES, chestSpecialOneIn)
13. dev note The Specials Armory: every special you have ever owned adds crit chance and crit damage.
    Source: game.js patch note and Specials Armory tooltip
14. confirmed Combat tools give +1% to +5% XP per tier (double the skilling curve) to the 10 combat skills.COMBAT_TOOL_TIER_BONUSES = [0.01,0.02,0.03,0.04,0.05]
    Source: Constants.js:1957-1979

More in Combat and raids

Ancient and Chaos shards and slates · Chaos Dungeon · Combat styles and Life/Spirit · Corruption · Death · Delve (combat raid skill and tree) · Dungeons (tiered raids) · Fortify talent tree · Fortress (skilling raid) · Fortress Ledgers and Banners · Fortress rares · Raid wave respawn · Slay masters · Slay tasks

Statuses: confirmed is a value or rule in the game files; observed is measured from recorded play; dev note comes from a developer comment, tooltip or patch note; inferred is worked out from the files with the assumption stated; unknown is decided on the server. Game data read 2026-10-03.