From the rulebook (available for pay-what-you-want at DriveThruRPG):
The Book of Legends and Deeds is a supplement for any pen and paper roleplaying game to help facilitate the creation of stories and deeds for player characters ("PC"). It can be used to generate rich character histories. It can be used to create on-the-fly encounters, and it also contains a way to get players more active in coloring the world and game.
BOLD is universal. It was designed to be run with every standing genre in tabletop roleplaying. Some terms must bend a little more depending on a genre. For example, "science" might be alchemy in a swords and sorcery campaign or a "monster" might be a horrible human being in a modern game. The terms are not definite answers that restrict possibilities; they are ideas to get the creative juices flowing.
Webapp created by Dan Conley.