Game Mechanics
The formulas that drive combat and experience, transcribed straight from the game. Use the calculators to plan your build.
Combat
Accuracy (will my hit land?)
Both you and your target roll a random number. You roll up to (Attack level + 20) × (Attack bonus + 20);
the target rolls up to the same with their Defence. If your roll is higher, you hit. The +20 to
each term keeps low-level players from missing forever against tough enemies.
Max hit (how hard?)
max hit = floor(1 + Strength/16 + Strength bonus/4).
On a successful hit you deal a random 1…max hit damage.
Attack speed
Both melee and ranged attacks fire every 0.7 seconds. A Slayer helmet adds +15% damage against your current task.
Weaknesses
Some creatures take extra damage from one combat style. A weakness doesn't add damage directly — it makes you hit far more often by ignoring part of the target's Defence bonus in the accuracy roll above.
This matters most against heavily armoured enemies. A Green Dragon has a +120 Defence bonus, but Ranged attacks ignore 60% of it — so a bow rolls against +48 instead. That is the difference between missing almost every swing and landing hits regularly, which is why dragons are fought with a bow.
A creature's weakness is listed on its bestiary page and tagged on the bestiary list, so you can pick your gear before you travel.
Status Effects
Some weapons, arrows and monsters apply a damage-over-time effect when they land a hit. Both kinds work identically — only the flavour differs.
Fire damage over time. Dragonfire, and the Dragon Crossbow's bolts.
Physical damage over time, from gem-tipped arrows.
- One tick per second. A 4-second burn deals its damage four times, on its own clock — server load and attack speed don't change the total.
- It refreshes, it doesn't stack. Re-applying the same effect resets the timer and keeps the stronger damage. A fast weapon can't pile up a dozen bleeds.
- It can't kill. Damage over time stops at 1 health and never lands the killing blow — for you or for the monster. Something has to finish the job with a real hit.
- Burning ticks show as orange numbers floating over the target, bleeds as deep red, so you can tell them apart from ordinary hits.
XP & Levels
Every skill uses the same curve and caps at level 99 (13,034,431 XP). The cost of each level grows exponentially — the second half of the grind is the long one.
Show full 1–99 XP table
| Level | Total XP | XP for level |
|---|---|---|
| 1 | 0 | 0 |
| 2 | 83 | 83 |
| 3 | 174 | 91 |
| 4 | 276 | 102 |
| 5 | 388 | 112 |
| 6 | 512 | 124 |
| 7 | 650 | 138 |
| 8 | 801 | 151 |
| 9 | 969 | 168 |
| 10 | 1,154 | 185 |
| 11 | 1,358 | 204 |
| 12 | 1,584 | 226 |
| 13 | 1,833 | 249 |
| 14 | 2,107 | 274 |
| 15 | 2,411 | 304 |
| 16 | 2,746 | 335 |
| 17 | 3,115 | 369 |
| 18 | 3,523 | 408 |
| 19 | 3,973 | 450 |
| 20 | 4,470 | 497 |
| 21 | 5,018 | 548 |
| 22 | 5,624 | 606 |
| 23 | 6,291 | 667 |
| 24 | 7,028 | 737 |
| 25 | 7,842 | 814 |
| 26 | 8,740 | 898 |
| 27 | 9,730 | 990 |
| 28 | 10,824 | 1,094 |
| 29 | 12,031 | 1,207 |
| 30 | 13,363 | 1,332 |
| 31 | 14,833 | 1,470 |
| 32 | 16,456 | 1,623 |
| 33 | 18,247 | 1,791 |
| 34 | 20,224 | 1,977 |
| 35 | 22,406 | 2,182 |
| 36 | 24,815 | 2,409 |
| 37 | 27,473 | 2,658 |
| 38 | 30,408 | 2,935 |
| 39 | 33,648 | 3,240 |
| 40 | 37,224 | 3,576 |
| 41 | 41,171 | 3,947 |
| 42 | 45,529 | 4,358 |
| 43 | 50,339 | 4,810 |
| 44 | 55,649 | 5,310 |
| 45 | 61,512 | 5,863 |
| 46 | 67,983 | 6,471 |
| 47 | 75,127 | 7,144 |
| 48 | 83,014 | 7,887 |
| 49 | 91,721 | 8,707 |
| 50 | 101,333 | 9,612 |
| 51 | 111,945 | 10,612 |
| 52 | 123,660 | 11,715 |
| 53 | 136,594 | 12,934 |
| 54 | 150,872 | 14,278 |
| 55 | 166,636 | 15,764 |
| 56 | 184,040 | 17,404 |
| 57 | 203,254 | 19,214 |
| 58 | 224,466 | 21,212 |
| 59 | 247,886 | 23,420 |
| 60 | 273,742 | 25,856 |
| 61 | 302,288 | 28,546 |
| 62 | 333,804 | 31,516 |
| 63 | 368,599 | 34,795 |
| 64 | 407,015 | 38,416 |
| 65 | 449,428 | 42,413 |
| 66 | 496,254 | 46,826 |
| 67 | 547,953 | 51,699 |
| 68 | 605,032 | 57,079 |
| 69 | 668,051 | 63,019 |
| 70 | 737,627 | 69,576 |
| 71 | 814,445 | 76,818 |
| 72 | 899,257 | 84,812 |
| 73 | 992,895 | 93,638 |
| 74 | 1,096,278 | 103,383 |
| 75 | 1,210,421 | 114,143 |
| 76 | 1,336,443 | 126,022 |
| 77 | 1,475,581 | 139,138 |
| 78 | 1,629,200 | 153,619 |
| 79 | 1,798,808 | 169,608 |
| 80 | 1,986,068 | 187,260 |
| 81 | 2,192,818 | 206,750 |
| 82 | 2,421,087 | 228,269 |
| 83 | 2,673,114 | 252,027 |
| 84 | 2,951,373 | 278,259 |
| 85 | 3,258,594 | 307,221 |
| 86 | 3,597,792 | 339,198 |
| 87 | 3,972,294 | 374,502 |
| 88 | 4,385,776 | 413,482 |
| 89 | 4,842,295 | 456,519 |
| 90 | 5,346,332 | 504,037 |
| 91 | 5,902,831 | 556,499 |
| 92 | 6,517,253 | 614,422 |
| 93 | 7,195,629 | 678,376 |
| 94 | 7,944,614 | 748,985 |
| 95 | 8,771,558 | 826,944 |
| 96 | 9,684,577 | 913,019 |
| 97 | 10,692,629 | 1,008,052 |
| 98 | 11,805,606 | 1,112,977 |
| 99 | 13,034,431 | 1,228,825 |
Combat XP: 4 XP per damage to the attacking style, plus 1.33 XP per damage to Hitpoints.
Combat Level
base = (Defence + Hitpoints + floor(Prayer/2)) / 4, then add the
best of melee (Attack+Strength)×0.325, ranged Ranged×0.4875 or magic Magic×0.4875, then floor.
Player Stats
- Max HP = your Hitpoints level (you start at 10).
- Max Prayer = 10 + Prayer level.
- Max Mana = 10 + Magic level × 2.
- HP regen = 2% of max HP every 15 seconds (at least 1). The Rapid Heal prayer doubles it.
Gathering
- Mining: success per swing = rock base + pickaxe bonus + 0.3% per level above the requirement, capped at 40%.
- Woodcutting: success per swing = tree base + axe bonus + 0.5% per level above the requirement, capped at 95%.
- Farming: crops grow over real time in stages and can catch disease; compost halves disease chance and adds a harvest.
Per-rock and per-tree numbers are on each skill guide.
Loot
- Gold drops scale with the creature's level.
- Standard drops each roll independently against their own chance.
- Loot tables roll once for the table, then pick one item by weight — so a creature's drop page shows the effective chance (table chance × item weight share).
- Dropped items are protected for the killer for 10 seconds before anyone can grab them.