From Introduction: Contained here are common monsters and other adversaries along with guidelines on how to advance them in level, skill, and effectiveness. The reason terms like ‘adversary’ and ‘opponent’ are used instead of ‘monster’ is because monster is a specific kind of adversary while there are many types of opponents characters may encounter such as wild animals, monstrous insects, human adversaries, dark elf villains, dwarven henchmen, halfing thieves, as well as traditional monsters.