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.