Many Notorious Monsters, as well as some ordinary monsters, appear via Lottery Spawn. This means that when a Spawn Point for an enemy is about to be filled, there is a random chance (as if drawn from a lottery) that another monster may spawn instead.
- For example, one of the Damselflies above Whitebone Sands (Valkurm Dunes), has a chance to spawn as the Valkurm Emperor.
Monsters who share their spawn with a Lottery Spawn monster are referred to as "placeholders". Killing a placeholder frees up the spawn point, allowing the lottery to "roll again" to determine which monster will spawn. This is the critical difference between lottery spawns and other spawns: if the placeholder for a lottery spawn monster is never killed, then the monster will never appear. Placeholders are usually, but not always, in the same family as the monster. Many notorious monsters have 1 placeholder, though some, like Leaping Lizzy may have 2 or more. Placeholders may be immune to charm effects to stop Beastmasters from delaying respawns.
When a Lottery Spawn monster is defeated, there is sometimes a certain amount of time before it can be placed back in the lottery to spawn again. This is most often referred to as the monster's "respawn time," though it can be more accurately referred to as the opening of the monster's spawn window. The variability of the lottery ensures that the monster will not necessarily reappear after that specific amount of time has passed, though it can be considered the minimum time the monster can take to spawn again. Because lottery spawns are based on chance, lottery spawn monsters have no definite maximum time to spawn and will sometimes take much longer than the average spawn time.