Armour is something you generally wear that protects you from both types of physical damage (cutting and blunt).

There are two major types of armour: shields and body armour. Shields must be wielded to provide their defense. Body armour is either a worn item, or is granted by some sort of ability. Additionally, worn body armour can be imbued with enhancements that increase its effectiveness in various ways (see HELP ENHANCEMENTS for details).

For worn armour, the key piece of armour is whatever covers the upper body, e.g. leather vests or scalemail jackets. Other armour pieces, such as leggings, are purely decorative.

The types of armour and their physical damage reductions are as follows:

- Leather armour: No damage reduction. This armour can be worn by anyone.
- Forged shields: 3% damage reduction.
- Shield runes: 5% damage reduction.
- Tattoo Preparation: 8% damage reduction. Granted by the Tattoos Preparation ability.
- Great robes: 12% damage reduction. This armour can be worn by anyone.
- Tattoo Armour: 14% reduction. Granted by the Kata Tattoos ability. This armour will have no effect if any worn armour other than leather is used.
- Splendour robes: 16% damage reduction. This armour can only be worn by the tailor that made it, but will only provide great robes-level defense if tailoring is not an active tradeskill. 
- Master Tattoo Armour: 18% reduction. Granted by the Tattoos TattooMaster ability. Same restrictions as tattoo armour.
- Forged Armour: 20% reduction. Can be worn by any non-acrobatics user.
- Master Armour: 25% reduction. Granted by the forging Masterarmour ability. Can only be used by the owner, and will only provide forged armour-level defense for non-forgers.

Additionally, those with the kephera demigod perk will gain armour equivalent to splendour robes, so long as they are not wearing any armour other than leather.