An abbreviation for "Adult Interactive Fiction", a genre of IF that deals with adult themes or situations (most usually sexual).
Typically AIF games are focused on sexual activity and would commonly be considered pornographic.
The AIF community is somewhat divided from the mainstream IF community. Few AIF games are entered in the IF Competition, and AIF is rarely discussed in rec.arts.int-fiction. Instead the bulk of AIF discussion takes place on the Yahoo! group aifarchive (formerly, discussion took place on Usenet, in the alt.games.xtrek newsgroup, but that has been largely abandoned since the creation of the aifarchive group). The AIF community is quite active; there is a community blog and subreddit.
A relatively high proportion of AIF games are written in Adrift, with TADS and RAGS also popular options. Several AIF authors were early adopters of TADS 3, possibly due to its sophisticated conversation system. The majority of AIF games are not uploaded to the IF Archive, but instead appear in other places such as Matrix Moles AIF Archive, or various Yahoo! groups pages.
Many authors without a centrally-AIF focus have written games which can be considered AIF, such as Adam Cadre's I-0 (Jailbait on the Interstate) and Robb Sherwin's Chicks Dig Jerks. James Mitchelhill's much-derided Kallisti is the best-known of the handful of AIF games entered in the IF Competition, and is certainly literary in intent. Likewise there are a number of AIF games that include quality programming, interesting puzzles, and/or good writing.
The great majority of AIF has a male protagonist, although there are exceptions. Games routinely cover sexually taboo subjects, most commonly heterosexual or lesbian content, but games featuring BDSM, male homosexuality, mind control and gender transformation have also been written.
Although they necessarily have a strong focus on NPCs, interaction tends to be somewhat limited and few contain conversation systems; a standard model involves perfunctory seduction performed by simple puzzles, followed by explicit sex involving a great many body-part objects.
The genre has attracted several parodies, notably Adam Thornton's Stiffy Makane: The Undiscovered Country, a parody of the truly atrocious The Incredible Erotic Adventures of Stiffy Makane; and Blow Job Drifter by Big Al.