Police Quest (or SWAT) is a series of police simulation video games produced and published by Sierra On-Line between 1987 and 1998. The first five were adventure simulation games, the first three of which were designed by former police officer Jim Walls. The fourth to sixth titles were designed by former LAPD Chief Daryl F. Gates. Both SWAT and the real-time tactics game SWAT 2 still carried the Police Quest name and were numbered V and VI in the series, respectively, although subsequent titles in the series would drop the Police Quest title altogether and were rebranded as SWAT.

We always wanted to put more into the games and I was never fully satisfied with the driving interfaces. However, the payoff came with the fan mail. When the letters came in, with some of the kids saying they wanted to grow up to be cops, we knew we were on the right track.

— Jim Walls, as told to USGamer

The first three games were produced by former police officer Jim Walls and follow the adventures of Sonny Bonds, a character whose name and appearance was loosely based on his own son, Sonny Walls. Jim Walls makes a cameo appearance in each game, typically in the introduction.

Released in 1987 using Sierra's Adventure Game Interpreter parser engine, Police Quest casts the player as Sonny Bonds, a 15-year veteran police officer in the fictional town of Lytton, California. Assigned to traffic duty, Sonny investigates what appears to be a simple car crash but turns out to be a homicide. Relieved by his supervisor, Sergeant Dooley, Sonny goes on a short coffee break with a fellow officer and returns to duty. He gives a traffic violation citation to a driver, single-handedly faces a tough gang of drunken bikers, and makes a DUI arrest. As the game progresses, he advances from patrol officer to temporary narcotics detective to undercover agent in hope of tracking down a murderous drug dealer named Jessie Bains, "The Death Angel". In order to find Jessie Bains, Sonny enlists the help of his former high school sweetheart, "Sweet Cheeks" Marie, who is now working as a prostitute.

The game is the most realistic of those developed by Sierra in the late 1980s when compared to Leisure Suit Larry, King's Quest, or Space Quest, and featured many puzzles where proper police procedure is required to succeed. It was released for MS-DOS, Apple II, Mac, Amiga, Atari ST and Apple IIGS. A SCI1.1 enhanced remake in 256 color VGA was released in 1992, which was also the first game released in the series not to feature dead ends.

Released in 1988 and running on the then-current SCI0 engine, the game once again casts the player as officer Sonny Bonds. After arresting Jessie Bains, Bonds is permanently promoted to the homicide division. He begins dating Marie Wilkans, who helped him in his undercover work in exchange for the dismissal of prostitution charges against her as "Sweet Cheeks" Marie. A dark shadow is cast over Sonny's happy life, however, when Bains escapes from prison and seeks revenge. With the help of his partner Keith, Bonds must protect his girlfriend's life as well as his own while pursuing "The Death Angel" once again. Despite Sonny's efforts, Bains kills several people who were involved in his arrest and abducts Marie. Sonny pursues Bains to Steelton, the current home of Donald Colby, a reformed drug pusher from the original Police Quest.

Police Quest II is notably more "mature" than the first title in the series and relies much more on proper procedure. Failure to properly maintain Sonny's firearm at various points throughout the game will cause it to malfunction or misfire, and proceeding into a dangerous situation without proper backup will usually prove fatal.