Game Mechanics

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.

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.

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.