Mordenkainen's Tome of Foes

Mordenkainen's Tome of Foes is a detailed sourcebook for Dungeons & Dragons that expands on the game's lore and introduces new threats, allies, and mythologies. It explores the conflicts between different powerful entities—such as demons, devils, elves, and undead—and provides guidance for game masters to create rich, complex stories. The book offers new monsters, character options, and insights into the cosmic battles shaping the game's universe, helping players and dungeon masters deepen their understanding of D&D's intricate fantasy world.