Tank

Disambiguation
'Tank' can refer to either:
 * The method of power levelling a player.
 * or
 * The role of a player who absorbs damage to protect others.

Definition
The term 'Tank' refers to a player or mob who absorbs a large share of incoming damage to prevent their less durable allies from taking it. This is accomplished in one of several ways for players; either by aggro'ing non-target changing mobs before their allies or by use of special skills such as the Crusader/Paladin Sacrifice skill. Players who make good tanks are characterised by an ability to withstand, shrug off or avoid large amounts of the total damage dealt to them. Though Agility based players can Tank it is less of a sure thing than Vitality based characters. In Ragnarok the Swordsman class tree make excellent tanks because of their high HP modifier, their ability to wear more powerful defensive gear and their much coveted Provoke skill.

Power Levelling by Tanking
The act of Tanking is a form of power levelling lower level players. In this form a higher level player uses their least damaging attack on a non-target changing mob and endures the damage it returns so that the lower level player can slowly kill the monster without fear of death. This is generally done on monsters of much higher level than the lower level player so as to maximise experience yield. This method of power levelling is much less common in TM due to the much higher Even Share Experience limit. However many players mistakenly refer to Leeching as Tanking, often asking for a "tank" when they mean Leeching.