This supplement introduces one of the most popular genres of anime to players of d20 System role-playing games: the "mecha" world of giant transforming robots, powered battle armor, star-spanning space cruisers, speedy hot rods and motorbikes, military assault vehicles, giant mechanical monsters, and much more. The d20 Mecha book provides a detailed, point-based creation system for all mecha types, making it an essential supplement for Big Eyes, Small Mouth d20 or any other d20 System game. Additionally, d20 Mecha explores the common mecha story conventions, with game rules covering prestige classes, character options, combat maneuvers, hit locations, and campaign suggestions.

Inspired by the dynamic settings and stories found in a wide range of anime shows, BESM d20 allows players to create characters from any genre or sub-genre. Comedy or horror, fantasy or science-fiction, mecha action or passionate romance...if you can imagine it, you can play it. BESM d20 also includes: new character classes (including magical girl, mecha pilot, pet monster trainer, and a dozen more), new skills, new feats, an exhaustive point-based attribute list, and a detailed cost assignment for the core 3.5 Edition fantasy races and classes.