Dark Dungeons is a retro-clone that emulates a specific out-of-print edition of a specific game. For legal reasons, neither that game nor the edition are named anywhere within this site or within Dark Dungeons itself. However, this doesn’t matter. If you know the game then you will pretty much instantly recognise it, and if you don’t know the game then it doesn’t matter – you can play Dark Dungeons on its own merits.
Dark Dungeons is a complete fantasy role-playing game, giving you everything you need from basic dungeon adventures through to exploring the multiverse as immortal beings of divine power. It provides everything you need in a single book, without the need for cross-referencing between multiple volumes or supplements.
The current edition of Dark Dungeons is Dark Dungeons X – the 10th anniversary edition of the game that also includes all the material from Darker Dungeons and more. This is available in both PDF and print format at DriveThruRPG here.
(If you want the original version of Dark Dungeons, that hews more closely to its source material, that is available in PDF format at DriveThruRPG here.)