Sierra On-Line — Developer

USA · Founded 1979 · Developer / Publisher

Sierra On-Line pioneered the graphical adventure game with Mystery House (1980) and King's Quest (1984), building one of the richest catalogues of story-driven games in gaming history.

Ken and Roberta Williams founded Sierra On-Line in 1979 — originally as On-Line Systems — in Simi Valley, California, moving to Coarsegold soon after. Roberta's Mystery House (1980), the first adventure game to feature graphics alongside text input, was programmed by Ken and sold from their home in plastic bags. The game's success funded Sierra's expansion into one of the dominant PC game publishers of the 1980s. The King's Quest series, which debuted in 1984 as a showcase for IBM's new PC Jr., introduced animated protagonists and a third-person perspective to the adventure genre. Sierra's catalogue expanded to include Space Quest (comedy sci-fi), Police Quest (procedural crime), Leisure Suit Larry (adult comedy), and Gabriel Knight (Gothic thriller authored by Jane Jensen). At its peak in the early 1990s, Sierra employed over 1,000 people across multiple studios. The company was acquired by CUC International in 1996 and effectively dismantled by 1999 after corporate restructuring eliminated the adventure game division.