Dōjin soft (同人ソフト), also sometimes called dōjin games (同人ゲーム), with dōjin sometimes transliterated as doujin or doujinshi, are video games created by Japanese hobbyists or hobbyist groups (referred to as "circles"), more for fun than for profit; essentially, the Japanese equivalent of independent video games or Fangames. Most of them are based on pre-existing material ("modding"), but some are entirely original creations. They are almost always exclusive to Windows-based PCs, but a few notable exceptions also exist for the Dreamcast, a console on which homebrew development was popular.
Dōjin soft are typically available in "demo" or "trial" (体験版 taikenban) form for free on the internet, with full versions available for purchase. One game, French-Bread's brawler Ragnarok Battle Offline, a homage/spoof of the MMORPG Ragnarok Online so impressed Gravity Corp. (the original game's designers) that it has been given an official release outside Japan.
Like fangames, dōjin soft frequently use characters from existing games, anime, or manga. These unauthorized uses of characters are generally ignored and accepted by the copyright holders, and are seen as encouraging a greater fan community. There are also many dōjin soft titles which are completely original, or feature only vague allusions to other series.
While most dōjin soft sales occur at anime and video game or anime conventions (such as Comiket), there is a growing number of specialized internet sites that sell them. Some titles sell well enough that their creators can make a full-time job out of their "amateur hobby". One particular circle, TYPE-MOON, has since become a commercial videogame developer.
Dōjin soft games typically do not get released outside Japan due to language barriers. Recently, independent Western developers have offered to help translate these games for release in other markets, with one of the first known successful examples being Recettear: An Item Shop's Tale, developed originally by EasyGameStation in 2007, and then localized and released by Carpe Fulgur in 2010 for English audiences, which had a modest success with over 300,000 units sold in these markets. This approach has been used to bring other dōjin soft games, particularly visual novels and dating sims, to the West.