In the beginning, the company was called On-line Systems but in 1982 changed its name to Sierra On-Line. The company's logo became Half Dome Mountain, located an hour's drive from the company's headquarters. ¹⁾

Mystery House was the first game written by Roberta and Ken Williams. It went into limited distribution (actually to four stores in Los Angeles where Ken had contacts), the game soon became a commercial success. Buyers were not deterred even by the amateurish packaging, which consisted of a floppy disk and a paper manual packed in a plastic bag. In three months the game sold nearly 10 thousand copies. ²⁾

At a computer trade show, Ken met Chuck Benton, a programmer who had written an adventure game about picking up girls for fun. Softporn Adventure was the complete opposite of the titles On-Line Systems offered, due to its bawdy nature, but Mr. and Mrs. Williams believed in the game's success, so much so that Roberta posed topless for the game's cover. ³⁾

Roberta Williams was contacted by Jim Henson himself, aka the creator of the Muppets. Jim was a fan of Sierra games and wanted Roberta to write a game based on his upcoming film The Dark Crystals. Working with Henson led to more connections in the film industry, which led to several games based on licenses in the future. ⁴⁾

The Black Cauldron was another game produced for Disney, being an adaptation of the film with the same title. Unfortunately, the film's failure in the cinemas meant that the game never achieved the expected success. It is worth noting that TBC was one of the first adventure games with multiple endings. AL Lowe worked on both games as the main programmer. ⁵⁾

In 1987, Ken Williams decided to expand his portfolio by producing a crime adventure game. The new series was called Police Quest. Unlike many police games, there was not much focus on action. Instead, the player had to complete all the normal police procedures often absent from movies and TV series. This was accomplished by involving a real police officer, Jim Walls, who was on sick leave after a shooting in which he was involved. ⁶⁾

King's Quest IV: The Perils of Rosella was developed on a new engine called SCI0, which used a higher resolution (320×200 instead of 160×200). Another novelty was the use of a sound card by the game. The new engine required a really strong computer. ⁷⁾

In addition to the technical advances, King's Quest 4 was one of the first high-budget games with a female protagonist, which raised some doubts among both Sierra employees and people working in the industry, but market research showed that players would enjoy playing a female character. ⁸⁾

King's Quest V is the first (and only) installment of King's Quest to hit the NES console, albeit in a slightly censored version (dialogue referencing religion was removed). ⁹⁾

In Police Quest III: The Kindred critics noted that the game strangely changes tone at one point. the reason was the departure of the game's creator, Jim Walls, from Sierra. Jim had an argument with his bosses over organizational issues at one stage of production and moved on to a competitor, leaving the game unfinished. To work on it was assigned, later industry legend Jane Jensen, who could write great scripts, but knew nothing about police procedures and hence the sudden change in tone of the game. ¹⁰⁾