Aggressive

Aggressiveness (or hostility) refers to whether monsters in RuneScape will attack nearby players without being provoked. Aggressive monsters may attack players without being attacked first; some are aggressive based on players' combat levels, and others are aggressive regardless of level such as various bosses and monsters in the Wilderness. Aggressive monsters can be particularly dangerous in a multi-combat area with multiple monsters. Non-aggressive, or passive, monsters will not attack players unless they are attacked first.

Some monsters, such as chompies and jubblies, will not attack a player even if engaged in combat. Yet, others, most notably dark beasts and bosses, remain hostile no matter how long the player remains in the vicinity.

When aggressiveness is based on combat level, an aggressive monster will attack a player whose combat level is less than or equal to twice the monster's level. If the player's combat level is more than twice the monster's level, it won't attack (i.e. double the monster's combat level plus one).

For example, a level 51 player enters an area with a level 28 hobgoblin. Since the player's level is less than twice the monster's level (28 × 2 = 56, which is more than 51), the hobgoblin will attack the player. Conversely, if a level 105 player enters an area with a level 28 hobgoblin, the monster will not attack because the player's level is more than twice the monster's. In this case, the hobgoblin will ignore the player (unless, of course, the player decides to attack the monster). Thus, the player would need to be level 57 or higher to avoid being attacked by the hobgoblin.

Different monsters seem to have different levels of aggression; some, such as jungle horrors, will seek you out from many spaces away, whereas others, such as mountain trolls, are aggressive on a smaller range.