Roberta Williams is an American video game designer, writer and co-founder of Sierra On-Line. Williams is best known as the co-founder of Sierra On-Line and the creator of the King’s Quest series that was extremely popular in the mid 1980s and early 1990s.

Williams’ first venture into video games began in 1979 with the creation of the first adventure game to incorporate graphics, Mystery House. Prior to Mystery House all previous adventure-based games were text only. Williams’ follow up game Wizard and the Princess added color graphics, another first for the industry. The success of Williams’ games helped establish On-Line Systems, a company she co-founded with her husband Ken Williams.

Over the course of the next couple of years Roberta continued to write and design games while establishing a very successful development and publishing company. From 1980 to 1983 On-Line Systems grew from having one employee, Ken’s brother John to over 130 employees. In 1982 the company was renamed to Sierra On-Line and the company moved to Oakhurst, California.

IBM approached Sierra to create a game to showcase their new computer the PCjr. Accepting IBM’s offer, Roberta Williams created a story featuring classic fairy-tale elements. Her game concept includes animated color graphics, a pseudo 3D-perspective where the main character is visible on the screen, a more competent text parser that understands advanced commands from the player, and music playing in the background through the PCjr sound hardware.

In mid-1984, King’s Quest: Quest for the Crown was released to much acclaim, beginning the King’s Quest series. It was the first animated 2.5D adventure game and spawned a multitude of sequels. The King’s Quest series, a saga about the adventures of the royal family of Daventry, would comprise eight adventure games before Roberta’s retirement in 1999.