In ADOM, each monster is typically categorized based on attributes relating to the monster's race, body type etc.. Each monster shares certain attributes with other monsters in the same category — usually including a common vulnerability to certain weapons (such as missiles "of -foo- slaying").

Such categories are commonly referred to as monster types, or mob types.

Listed below are all the known monster types in ADOM. Note that a number of known monsters do not appear to belong to any of these categories; rather, their monster type can be said to be "Unknown". Furthermore, it is possible for a monster to fall into more than one category — e.g. golems are construct humanoids, and Andor Drakon appears to be a demonic humanoid.

Other monster types that may exist in the game are Rabbit (seeing as a weapon in the game specifically slays rabbits; although there are only two known members of the group), and Rat (seeing as Cat's Claw slays rats and giant rats).