Erotic Game

An erotic game (eroge) is a Japanese video or computer game that features erotic content, usually in the form of anime-style artwork. In English, eroge are often called hentai games in keeping with the English slang definition of hentai. This is sometimes shortened to H games. In Japan, eroge are also referred to as 18+ games. Most erotic games are visual novels or dating sims but are not limited to them.

Any anime adaptation of a game that contains (or had a version that contains) adult content (generally sex scenes), regardless of how some fanboys blabber on how "the story in that visual novel was too good to be labelled as porn!", should definitely get this category added under them. This should make it pretty clear as to what is an erotic game and what is not.