An episodic video game is a video game of a shorter length that is commercially released as an installment to a continuous and larger series. Episodic games differ from conventional video games in that they often contain less content but are developed on a more frequent basis.
Such a series may or may not have continuity, but will always share settings, characters, and/or themes. Episodic production in this manner has become increasingly popular among video game developers since the advent of low-cost digital distribution systems, which can immensely reduce their distribution overhead and make episodes financially viable. Alternatively, it can be used to describe the narrative of the game. Examples of episodic video games include most Telltale games, Alan Wake, BioShock Infinite: Burial at Sea, Grand Theft Auto: Episodes from Liberty City, Life Is Strange, Resident Evil Revelations, Revelations 2, and Star Trek Online.
To consumers, episodic games are very similar in nature to expansion packs. An expansion is an add-on to an original, non-episodic product however; something of a lower order. In an episodic series there is no dominant '"first" game': each installment, although perhaps of the same length and price point as an expansion, is a main event that drives the core experience forward.
The first episodic game appeared in 1979. Automated Simulations' Dunjonquest series started with Temple of Apshai, and in the same year several mini-episodes using the same game system and world were released. The sequel Hellfire Warrior and several full-sized add-on packs for both main games followed 1980–1982.Wizardry was likewise appended with additional scenarios that allowed importing of the first games' save data.