The Combat triangle is a chart of the strengths and weaknesses of each combat class against the other classes. In general, when players are combatting opponents with skills close to their own skills:
- Warriors are strong against rangers. Rangers' projectiles can't penetrate metal armour very well, but warriors' blades can cut through leather with ease.
- Rangers are strong against mages. Their leather and dragonhide armours absorb the magic spells used by mages. Their arrows easily pierce the soft cloth of mage robes.
- Mages are strong against warriors. The metal that makes warriors' armour conducts spells so that the effect is more potent. Also, freeze/bind spells put warriors at a disadvantage because frozen warriors can't attack mages from a distance.
However, this does not guarantee that one class will always beat its weaker class. For example, a warrior can still defeat a lower levelled or worse-equipped mage, or a ranger can easily defeat a meleer who is stuck behind a fence.
Bending the triangle
The triangle tends to focus mostly on the effectiveness of armour.
- Against Rangers. The warrior's armour is most effective against ranged projectiles, though the ranger has an advantage as long as they can remain out of direct contact.
- Against Mages. The warrior's armour makes the mage's spells more potent. A warrior can take off metal armour or wear rangers' armour to raise magic defence; nevertheless, a mage can counter with binding spells.
- Against Warriors. The ranger can counter the warrior by evasion, or increase defence by switching to a chainbody.
- Against Mages. The ranger's armour is most effective against magic, and holding tactics cannot prevent the ranger from hitting the mage. Therefore, this is a side of the triangle that is almost impossible to collapse.
- Against Warriors. The mage's armour tends to offer little protection against warrior attacks. While the mage's attack hits easily through metal, warriors can still deal more damage in close combat. The mage can do little to change their position in the triangle, though members do have some more defensive armour options, such as splitbark. Also, members have access to the Ancient Magicks spellbook.
- Against Rangers. The ranger's armour is most effective against magic, and holding tactics cannot prevent the ranger from hitting the mage. Therefore, this side of the triangle is almost impossible to collapse.
Hybrids are capable of standing at more than one point on the triangle, though at some cost and compromise to their equipment and inventory load.
Before the Evolution of Combat, the Combat triangle favoured heavily towards melee, where warriors could easily overpower mages in most situations due to mages weak melee defence. Since the Evolution of Combat, the combat triangle is more effective. Magic was very underpowered and Ranged was partially underpowered too, but since the Evolution of Combat, some people think Magic and/or Ranged are overpowered compared to melee.
- In the top right corner, among the Dwarven script, there are three equations that are used in game to calculate a player's combat level based on whichever combination of statistics results in the highest combat level.
- In the background of the Dwarf "blueprint", a hexagram can be seen.
- Dragonfire is another form of attack, and is not part of the combat triangle. It defies the combat triangle and cannot be blocked with any protection prayer. Using Protect from Magic will only partially help the user.
- Damage inflicted by poison or a dwarven multicannon should also be considered another form of attack as Poison cannot be blocked by a protection prayer and a dwarven multicannon has its own symbol next to the damage inflicted by it showing that it does not inflict ranged damage but its own unique kind of attack instead. It is unknown if protect from range will defend a player from a cannon as it is impossible to expose a player to multicannonfire. However a monster with high range defence will be more difficult to hit with a multicannon and your range attack bonus does impact the multicannon's accuracy suggesting that multicannon damage and range damage are linked.
- Although summoning familiars usually attack from a corner of the combat triangle the prayer protect from summoning will protect you from their attacks even if multiple familiars are attacking you from multiple sides of the combat triangle.