Dungeons & Dragons Retro-Clones

A Retro-Clone is any modern role-playing game based on older Dungeons and Dragons game systems, such as Original D&D, Basic D&D and Advanced D&D. The modern renditions of these older D&D game mechanics are often based around the licensed d20 System (with many offering a choice between using that system or a variant of the older THAC0 system). The best are listed below, and all have been published in print (mostly hardbacks).


Basic Fantasy
Emulated System: Basic & Expert D&D, based on the 1981 'B/X' sets.


Castles & Crusades
Emulated System: Basic & Expert D&D, with a mix of Original D&D & Advanced D&D 1st Edition rules (supported by Gary Gygax, and from the author of OSRIC 1st Edition; see below).


Dark Dungeons
Emulated System: Basic & Expert D&D, based on the 1991 Rules Cyclopedia.


Dungeon Crawl Classics RPG
Emulated System: Advanced D&D, with a mix of Original & Basic D&D, as well as newly designed systems. The stated goal of the games developers was to create a 'pre-1982' Dungeons & Dragons style and feel.


HackMaster
Emulated System: Advanced D&D 1st & 2nd Edition.


Labyrinth Lord
Emulated System: Basic & Expert D&D, based on the 1981 'Red Box' rule set, with separate Basic and Expert rules.


Myth & Magic
Emulated System: Advanced D&D 2nd Edition.


OSRIC (Old School Reference & Index Compilation)
Emulated System: Advanced D&D 1st Edition.


Swords & Wizardry
Emulated System: Original D&D.