Dungeon Delving Brown Box Edition

Publisher's blurb:

Dungeon Delving Brown Box Edition is a retroclone of the original fantasy role-playing game published in 1974 (aka "0e"). It is an edited reconstruction (using open game content) of that game in easier to understand and use form. If you have wanted to play 0e but found the original rules confusing, disjointed, and apparently written for people who already understood the game, Dungeon Delving Brown Box Edition may be what you are looking for: a close emulation of the the original game presented in an organized manner intended for today's gamers instead of 1970's wargamers.