Pre-requisite for roach king to appear

[Genes]

Hi all, are there conditions for roach king to appear? Sometimes his cave is empty upon reaching.

[Malakov]

Enemies remaining. Almost every boss relies on this - usually for big bosses like that, you need 20 or less. Some people may know the exact numbers.

[Pharcyde]

It's because of the rushing nerf. Every boss level 40+ will not appear unless all major events or enemies in the cave have been cleared (lesser bosses, totem spawns, ect) and a certain number of enemies remaining. I don't know exact number for roach king, but its gotta be within the 6-20 enemies remaining line.

[wolfendragon]

Very good to know about roach king