The combat triangle is a basic diagram showing how weak or strong one fighting style is against another.

A Melee fighter overcomes a Ranger because swords can cut through A typical combat triangle.leather armour very easily. Melee armour is also effective against ranged ammo.
Rangers are able to overcome Magic users because of their long range, as well as ammunition which is able to penetrate through magic users' robes.
Magic users overcome Melee fighters because magic "conducts" through the metal armour, making magic attacks extremely effective against those wearing full Melee armour and Jagex quoted on the tip loading screen that it "Cooks" players in their own armour.

Many times, the combat triangle is not as straightforward as the case presented above. The triangle is subject to change from fight to fight due to differences between overall levels of combat, levels of a certain skill, different prayers, types of combat tactics, and amulets or other accessories that can change stat bonuses, affecting the outcome of the fight.

1.Ranged Armour tends to be more flexible material, like Leather or Dragonhide.
Ranged Armour is capable of defending against light attacks, but is weak against close-combat.
Ranged Armour also dispels Magic fairly well, while negatively impacting Magic Attack, though not as much as Plate Armour.
Ranged Armour offers the necessary mobility for Ranged Attack bonuses which most players wear while using Ranged Attack.

2.Magic Armour is not "armour" per se. It is more in the line of robes and other similar garments, but there are a number of more protective magic items. Some of these items give a bonus to your magic defensive levels which can be seen in the armoury tab.
Magic 'armour' is known for being very weak, and is preferable for magic casting, offering no negative influence, and not amplifying magic attacks. However, lightweight robes do not stop arrows or swords well, and therefore fall short in terms of protection against them.
Magic Armour is not "armour" per se. It is more in the line of robes and other similar garments, but there are a number of more protective magic items. Some of these items give a bonus to your magic defensive levels which can be seen in the armoury tab.
Magic 'armour' is known for being very weak, and is preferable for magic casting, offering no negative influence, and not amplifying magic attacks. However, lightweight robes do not stop arrows or swords well, and therefore fall short in terms of protection against them.

3.Highest Bonus Armours are the best equipment sets available for certain bonuses. Armour includes items that can provide bonuses during combat. These bonuses include attack and defence. These bonuses help boost or protect against the different attack styles. An example would be Bandos, for strength bonus.