Combat triangle

In this image, each fighter is attacking the one weaker than itself and being attacked with its own weakness.

Old School RuneScape follows the combat triangle, a design philosophy dictating that melee tends to be effective against rangers, ranged tends to be effective against mages, and magic tends to be strong against warriors. This philosophy manifests in the combat bonuses of armour and weapons, the ability of ranged and magic to attack from a distance or safespot, and weapon/armour/spell effects (such as the twisted bow's increased damage against monsters with high magic level.)

In terms of bonuses, melee armour tends to excel in melee defense and ranged defense; ranged armour tends to have substantial ranged attack, high magic defense, and middling melee and ranged defenses; and magic armour tends to offer magic attack bonuses and middling magic defense, but little to no ranged or melee defense.

In general, when players are combating opponents with similar combat skill, the combat triangle can offer a rule of thumb as to which combat style is most effective. It should be noted that the combat triangle in no-way defines a fight outcome; any combat style can be used effectively to kill opponents using any other combat style, the triangle simply suggests what is favourable.

Warriors

• Warriors are strong against rangers. Their armours deflect the projectiles used by rangers. Their weapons penetrate the leather armours worn by rangers and the robes used by mages. Melee is the most commonly used combat style, due to its lack of a consumable requirement and generally higher dps than magic or ranged. Overall, Melee is the best class defensively due to armour, which provides strong resistance to arrows and melee attacks. Warriors also make good tanks if they're being piled by multiple people. Their glaring weakness are magical attacks, which can become a problem. To counter this, many warriors wear partial ranger outfits.

Rangers

• Rangers are strong against mages. Their leather and dragonhide armours absorb the spells used by mages. Their projectiles easily pierce through the mage's robes. Ranging is the second most common method of combat due to its ability to attack over distance, high dps, and relatively cheap consumable cost. They can take down mages fairly quickly due to a mage's lack of good defensive armour, but they have more trouble taking down a warrior. Defensively, they're better than mages but worse than warriors.

Mages

• Mages are strong against warriors as long as they keep their distance. Their magic is amplified by the metallic armours usually worn by warriors. Mage-based armour (robes) offers little protection against any of the three combat styles. Spells can hit through melee armour fairly easily. They can also freeze, bind, weaken, confuse, or stun their opponents, giving magic the highest utility of the combat styles. For players to be effective mages, freezing melee combatants is essential. Magic is rarely used alone and is most effective when combined with another combat style - usually ranged, combining the utility of a mage with the distanced damage of a ranger. Magic suffers from a far lower maximum hit than other combat styles - Ice Barrage is tied with the god spells with a maximum base damage of only 30, potentially boostable to 48 with the maximum damage-boosting items and Flames of Zamorak. Ranged and melee can hit over twice as hard as this with special attacks from weapons such as the Dark Bow and Dragon Claws. Added to this, magic is most often out-performed in damage per second by a similarly levelled and geared user of another style, however this does not mean magic cannot deal considerable damage with higher level spells.

Bending the triangle

The triangle tends to focus mostly on the effectiveness of armour.

• A warrior's armour is most effective against ranged projectiles, as long as they can get close to a ranger. A warrior's armour is worse than useless against magic, thus removing metal armour and using ranged armour instead while closing in on the mage is the more effective strategy over remaining in metallic armour.

• A ranger's armour is most effective against magic. Holding tactics cannot prevent the ranger from hitting the mage. A ranger can counter a warrior by maintaining distance and kiting, or increasing Defence by switching to a medium helmet or chainbody.

• A mage's armour tends to offer little protection against ranger and warrior attacks. While a mage's attack hits easily through metal, it's advised to stay as far away as possible from warriors by running and/or using binding spells, as their weapons can easily pierce a mage's robes. A mage can counter warriors and rangers by substituting pieces of magical armour with a medium helmet, square shield, and even a chainbody to sacrifice some magical accuracy in order to substantially increase Defence.

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. PKers are often seen rapidly switching worn equipment to make maximum use of multiple attack styles.