High Quality Content by WIKIPEDIA articles! Dungeons & Dragons Online (DDO) is a massively multiplayer online role-playing game (MMORPG) developed by Turbine, Inc. for Microsoft Windows, and originally marketed as Dungeons & Dragons Online: Stormreach, then Dungeons & Dragons Online: Eberron Unlimited with the start of Free to Play, changing to Dungeons & Dragons Online with the introduction of Forgotten Realms related content. Turbine developed DDO as an online adaptation of Dungeons & Dragons (D&D) based loosely on the D&D 3.5 rule set. The game is set in the unexplored continent of Xen`drik within the Eberron campaign setting.