Sierra On-Line was a pioneering adventure game publisher that played a formative role in shaping the PC gaming landscape through the 1980s and 1990s. Its catalogue of around 181 titles includes landmark series such as the adult comedy Leisure Suit Larry, with entries like Leisure Suit Larry: Love for Sail!, as well as darker narrative adventures including Phantasmagoria and Gabriel Knight: Sins of the Fathers. Sierra's output helped define the conventions of the point-and-click and parser-based adventure genres.