Mythos is a multiplayer computer role-playing game that was under development by Flagship Studios Seattle, a subdivision of Flagship Studios, a video game company composed largely of ex-Blizzard North employees who were lead producers of the Diablo series. Due to financial issues at Flagship Studios, Flagship Seattle was subsequently dissolved with the full staff of 14 moving to the new game company Runic Games, leaving the intellectual property rights in the hands of the Korean game company HanbitSoft. HanbitSoft will continue to develop Mythos, then release it in South Korea and North America. Mythos is similar in style to Diablo, utilizing a similar interface and perspective, extensive map and item randomization, and a high fantasy setting. Its development was led by Travis Baldree, creator of the action RPG FATE, now a co-founder of Runic Games. The game started as an MMORPG intended to test the networking technology behind the multiplayer component of Flagship Studios` Hellgate: London, but has since grown into an independent game scheduled for a separate release.

Mythos shares the same core engine and technology that Hellgate: London uses. Features between the two games are often shared since they are so similar in technology. Starting in 2007, the game had been in an ongoing closed beta testing stage, with an open beta expected sometime during 2008. However, on July 19, 2008 it was announced that due to continuing financial hardships at Flagship Studios, Mythos would be going on hiatus. There is currently no information on whether or not the beta will re-launch. As Flagship has laid off most of its employees (two founding members remain), the development of Mythos has been suspended, to be continued by HanbitSoft. According to the developers` statements prior to the hiatus of July 2008, Mythos was to be digitally distributed by Flagship Studios subsidiary Ping0 in North America and Europe.