Defence
Players train the Defence skill to decrease the chance of being hit in a fight and to be able to wield better armour for melee, Magic and Ranging alike. Defence can be trained in any form of melee, magic or ranging combat with any weapon, spell or bow against Monsters or other players in the Wilderness or Minigames. A player must use the last combat style (generally Block or Longrange) to gain Defence experience. Only melee can purely train defence, if you train defence using ranged or magic, you will also gain ranged and magic experience. If you use melee on the defensive combat style, you will gain 40 Defence experience per hit.
A player can boost the Defence skill by using Defence potions, Super defence potions or Saradomin brews made with the Herblore skill. With potions players can reach a maximum Defence level of 123.
A higher Defence level will decrease the chance of being hit by your opponent in a fight. However, it will never nullify this chance, and it will not decrease the maximum damage of your opponent! You will significantly notice that players and monsters hit '0' more often on you. Attack is the contrary of Defence: it increases your accuracy.
A higher Defence level will enable you to wield more and different kinds of armour for melee, magic and ranging.