The first Dungeons & Dragons was published by TSR in 1974, growing out of earlier fantasy wargaming rules Chainmail. Since then it has developed through 'Basic' and 'Advanced' versions, the latter having two editions.

While earlier releases of the game involved improvements, additions and modifications to the original rules, the 3rd edition in 2000 featured a complete redesign of the core game mechanic with the development of the D20 system. This elegant mechanic, put simply, consists of rolling a single d20, applying various modifiers and comparing the result to a target or 'Difficulty Class' to see if you have accomplished what you were attempting to do. 'Version 3.5' was mostly a tidying-up and refining of the original D20 system, based on 3 years of extensive use, development and feedback.

This was followed by the 4th Edition of Dungeons & Dragons, which came out in June 2008, published by Wizards of the Coast. The 5th Edition launched in the summer of 2014, following an extensive public playtest.

Innovative licensing of the 'D20' system and the introduction of the Open Gaming Licence have led to an explosion of materials published as, subject to certain rules, anyone may produce game resources - settings, scenarios or whole game systems - using the core D20 mechanic. A similar licence is available to allow third-party publication for 4e.

Page last updated: 6 August 2014