Monster holding refers to instances wherein a player holds a monster to maintain claim on the monster. This is especially prevalent with monsters that a large amount of players are interested in, such as Notorious Monsters. Cases where there are no signs of effort to defeat a monster can be considered grief tactics. Monster holding can also be defined as a player or group of players attempting to regulate the time that a monster appears by keeping it claimed with the intention to shift its spawn time by delaying its defeat.

In an effort to maintain an enjoyable game environment, the GM staff may intervene and take appropriate action, such as instructing the player to either engage the monster in combat in an attempt to defeat it or release the claim on the monster in question. Players that do not follow a GM's instructions will become subject to account disciplinary actions.

As of August 2005, some specific monsters become more powerful after a certain amount of time has passed as an anti-holding measure. GMs will no longer interfere with these particular monsters.