The inclusion of sex and nudity in video games has been a controversial topic since the early days of the industry. While many video games have used scantily clad images or characters to sell or enhance games, some go further, using sex acts or nudity as a character motivation, in-game reward, or simply as a gameplay element. These games originate worldwide, on most platforms and can be of any video game genre. While releases in Europe and North America have been sporadic, Japan has seen the emergence of a pornographic video game subgenre—eroge.
One of the earliest video games (if not the first) to feature sexual themes was the 1981 text-based Softporn Adventure, published by On-Line Systems for the Apple II. Despite heavy piracy the game still sold 25,000 copies, roughly equivalent to 25% of the number of Apple II's sold at the time. In a 1981 article in Time Magazine, On-Line reported that they were making a version of the game for straight women, though this never materialized.
In 1982, Japan's Koei, founded by husband-and-wife team Yoichi and Keiko Erikawa (and later known for strategy video games), released the first erotic computer game with sexually explicit graphics, Night Life, an early graphic adventure game for the NEC PC-8801. That same year, Koei released another erotic title, Danchi Tsuma no Yuwaku (Seduction of the Condominium Wife), which was an early role-playingadventure game with colour graphics, owing to the eight-color palette of the NEC PC-8001 computer. It became a hit, helping Koei become a major software company.