Dominion Rules (DR) is a role-playing game system for historical and fantasy role-playing. DR is notable in the history of role-playing games for being one of the first RPGs to be released under an open source (or open gaming) licence, known as the Dominion Rules Licence.[1] Development of the game followed an open source model whereby contributors, known as the Dominion Games Development Team,[2] made improvements or additions to the game and published them on the internet (often through the Dominion Games web site) under the terms of the Dominion Rules Licence, thus explicitly encouraging the creation of new skills, spells, beasts and rules by its modular structure in an attempt to establish an equivalent to the Open Source Software model in RPG gaming.