Tolerance refers to certain monsters' behaviour in which the monsters stop being aggressive towards players after a certain amount of time (10–20 minutes (longer for the inhabitants of the abyss)) without the player leaving the area (about the size of what is shown in the minimap).If a player leaves the area and returns, the monsters will once again become aggressive towards that particular player. This does not include logging out and back into the game but does include teleporting away (by means of random events, spells, and the like). Jagex implemented tolerance to discourage AFK trainers, as they would then stop fighting after the tolerance begins and automatically log out. The timer stops counting if the player logs out. Therefore, logging out and in again would not immediately end the tolerance time.
Tolerance can be VERY annoying when killing rock crabs since the only way to attack them is for them to be aggressive, making them a dubious training exercise at Relleka, however, at Waterbirth Island, since they are in separate spots, it is not such a problem.
Some monsters that become tolerant may become aggressive again even if the player constantly stays in the vicinity. Kurasks in the Fremennik Slayer Dungeon portray this behavior as do the wild Dogs in Brimhaven Dungeon. Other monsters do not become tolerant at all no matter how long the player remains in the vicinity. For example, the King Black Dragon found in the King Black Dragon Lair will always attack any player in his lair. Warped terrorbirds in the Poison Waste Slayer Dungeon also remain permanently aggressive to players. Presumably, warped terrorbirds are the exceptions because players could not AFK train due to the fact that the player had to constantly cleanse the target before the player could deal any damage. However, now players can cleanse terrorbirds automatically, thereby opening them up to AFK training.Tolerance can be beneficial to the player in some cases. Hellhounds in the Taverley Dungeon are one example. When the hellhounds become tolerant, the player can safely attack from ranged safe spots without another hellhound intercepting them. In particular, players tend to AFK train on dark beasts because they do not become tolerant. By using high boosting prayer armour and the protect from melee prayer, a player would have to refill prayer only once every 5-10 minutes. However, dark beasts require 90 Slayer to damage them which stems the demand for training on them.