For genres used to classify games listed on the IFWiki, see: IFWiki:Genre.
Generally speaking, genre is a classification of creative works according to technical form, style, and/or subject matter.
In interactive fiction, one of the main formal differences that defines genre is game size (often thought of in terms of the time that must be invested in order to complete the game).
- full-length or epic -- these generally contain as much text as a novel, but require a far greater time investment, due to the inclusion of puzzles and/or multiple endings. Full-length works typically entail the creation of a complex backstory that can be enhanced by feelies.
- IF Competition entries -- in order to conform with rules of The Annual IF Competition (the major annual event of the IF community), these are typically designed to be played in under two hours.
- mini-comp entries or artshow entries -- works that are written for entry into a special one-time contest, or for Marnie Parker's IF Art Show. These works are typically small in scope, but need not be.
While the above descriptors divide IF up in terms of length/scope, IF is also divisible according to style (or perhaps mode?):
- apartment/dorm simulation -- a somewhat dismissive term for a favorite setting of many novice designers (a realistic simulation of the designer's house [or college campus], typically laden with in-jokes intended for the designer's friends).
- conversation-based -- the designer has created one or more NPC's of greater than usual complexity; gameplay consists largely of engaging in conversation with the NPC(s).
- CYOA -- delivers a plot mostly via prose chunks, occasionally asking the player to make a decision which will affect the content of the next story chunk.
- dungeon-crawl -- a fantasy-themed treasure-hunt, in the spirit of "Colossal Cave Adventure" and the "Zork" series, in which the exploration of a virtual universe (and the deduction of the rules that govern it) dominates the gameplay.
- experimental -- any attempt to refine, extend, re-envision, or otherwise challenge the conventions of a genre (as defined by glossaries such as this one).
- puzzle-fest -- a game that emphasizes the manipulation of objects or the deduction of rules, to the exclusion of any serious attempt at characterization or plot development.
- wordplay -- emphasizes IF as a textual medium, relying on language-related puzzles (translation, puns, etc.)
The subject matter of an IF work can vary widely. Many of the popular mid-80s commercial IF titles were puzzle-fests that borrowed the conventions of familiar literary sub-genres (detective, horror, science fiction, etc.).
In literature, the main genres are prose (including novels, short stories, and essays), verse (including epics and short poems) and drama (with variations such as ballet and opera). In computer games as a whole, the main genres may be defined as arcade, simulation/strategy, role-playing, and adventure, but these categories are much more fluid than those that define literature.