In KQ4 (both AGI and SCI) there is a reference Police Quest and Lytton in the Glass Bottle.
In KQ4AGI there is a reference to Police Quest II and Jim Walls. ""Jim Walls is busy writing Police Quest II and not here."
The KQ4 Hintbook makes a nod to the series; If you have enjoyed this game, I'm sure that you will like our other animated adventure games: King's Quest IV's predecessors -King's Quest I, II, III; The Black Cauldron; Space Quest I, II, III; Police Quest I and II; Leisure Suit Larry: In the Land of the Lounge Lizards and Leisure Suit Larry: Looking for Love in Several Wrong Places; Gold Rush!; Manhunter; and last but not least, Mixed-up Mother Goose for the little ones.
Police Quest 1[]
In Police Quest I EGA, The Lytton Tribune newspaper has an article about events of King's Quest III and the Three-Headed Dragon attacking Daventry, and mentions the gnome mentioning that the kingdom was in a 'state of emergency'.
Also in Police Quest I EGA, if you try to take a feather from the chicken on John Dooley's desk. The game comments; "Do that in \"King's Quest III.\"
The end of Police Quest plugs King's Quest I, II, and III.[1]
If you call Sierra Customer Service number in Morgan's office, King's Quest and other series are mentioned: "Hello, Sierra On-Line Customer Support, Larry Weissenborne speaking. How may I help you? But hurry up, 'cause I'm leaving soon! You know those crazy programmers; they can't do anything right the first time! Hint books are available for $7.95. Try calling this number to place your order, but next time use a REAL phone, not this game! King's Quest I, II and III, The Black Cauldron, Leisure Suit Larry in the Land of the Lounge Lizards, and Space Quest I and II. Police Quest II and others are now in development! Thank you for calling. Goodbye."
The Police Quest I main theme is a rearrangement of the KQ3 main theme music.
Police Quest 2[]
In Police Quest II if the player does something crazy such as shooting gun haphazardly at civilians, a newspaper is shown with a picture of Graham and Rosella mentioning that the "King Near Death!".
In Police Quest II King's Quest games information for the first 4 games can be found in the Crime Computer.[2]
Hoyle series[]
Sonny Bonds interacts with Rosella and Graham in Hoyle I.
Sonny Bonds again appears and can play against Rosella, Graham, Mordack & Lolotte.
↑"If you liked \"Police Quest,\" be sure to play the other 3D, animated, graphic adventure games from Sierra: \"King's Quest I, II, and III;\" \"The Black Cauldron;\" \"Space Quest I and II;\" and \"Leisure Suit Larry in the Land of the Lounge Lizards.\""; m7 = "You'll also enjoy our 3D \"Helicopter Simulator\" that allows you to have dogfights with your friends via modem, or just fly through many cities for fun."
↑KINGS QUEST I
Quest For The Crown
The original history-
making adventure game.
Be Sir Graham, bravest
of the Knights. Locate
lost treasures. Return
them to King Edward to
restore kingdom's lost
prosperity. In the end,
you may inherit the
throne.
KINGS QUEST II
Romancing The Throne
Explore caves, eerie
castle towers, and ocean
wonderlands. Help King
Graham unlock the secrets
that will lead him to the
enchanted maiden for whom
he longs.
KINGS QUEST III
To Heir is Human
Become Gwydion, young
slave to the evil wizard
Manannan of Llewdor.
Discover the wizard's
spells. Embark upon
dangerous voyages to
distant lands. Free a
Kingdom from its ravages.
KINGS QUEST IV
The Perils of Rosella
Travel with Rosella, the
beautiful princess and
heroine of King's Quest
IV. Journey to a town far
away. Search for the
enchanted fruit that will
restore life to her father
and safely return her
home. Meet creatures
from ancient legend, from
beautiful unicorns to
hideous ogres. Acquire
treasures that are
necessary to ensure your
safety. Save Genesta from
imminent death by
destroying the evil Lolotte
and returning the sacred
talisman which once rested
around her neck.