King's Quest IV

King's Quest IV: The Perils of Rosella
Apple II cover art
Developer(s)	Sierra On-Line
Publisher(s)	Sierra On-Line
Director(s)	Roberta Williams
Producer(s)	Ken Williams
Designer(s)	Roberta Williams
Programmer(s)	Chane Fullmer Ken Koch
Artist(s)	William D. Skirvin Carolly Hauksdottir Gerald Moore
Writer(s)	Roberta Williams
Composer(s)	William Goldstein
Series	King's Quest
Engine	AGI and SCI0
Platform(s)	MS-DOS, Amiga, Apple II, Apple IIGS, Atari ST
Release	September 1988
Genre(s)	Adventure game
Mode(s)	Single player

King's Quest IV: The Perils of Rosella is a graphic adventure game developed and released by Sierra On-Line in 1988. The player takes on the role of Princess Rosella, daughter of King Graham of Daventry (King's Quest I and King's Quest II) and the twin sister of Gwydion/Alexander (King's Quest III), who must save her father and a good fairy and defeat an evil witch. Critically acclaimed, it was one of the first PC games to support a sound card.

King's Quest IV uses the Adventure Game Interpreter and Sierra's Creative Interpreter systems. This is the only chapter in the King's Quest series where the action takes place in real-time. The events of the game cover about 24 hours. Some activities must be completed during the day, while other puzzles can be solved only at night. The difficulty of King's Quest III was toned down in King's Quest IV.

King Graham of Daventry has suffered a heart attack during quality time with his family and is on the brink of death. The good fairy queen Genesta contacts Rosella through a magic mirror and offers her assistance. Rosella is teleported to the fairy land of Tamir, where she learns about a magical fruit that can heal her father. However, Genesta herself is in a weakened state because her dark rival, Lolotte the witch queen, stole the talisman that gives Genesta power. If Rosella fails to vanquish Lolotte and return the talisman within one day and one night, Genesta will be unable to help her return to Daventry in time to save her father, and will even die.

Upon getting into Lolotte's castle, Rosella, disguised as a peasant girl, is charged with performing three tasks for the evil queen, who seeks Pandora's Box to rule the world. Completing these, Rosella earns the witch's trust and gains an opportunity to destroy her and recover the stolen talisman, and also to rescue a cursed prince named Edgar. Although Rosella's primary quest is to retrieve the magic fruit needed to save King Graham, it is possible to return to Daventry without completing this task, but this leads to a tragic alternate ending to the game. Winning the game will not resolve all storylines, although that will be the goal in the sequels.