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According to Don Bluth, Princess Daphne's design was heavily inspired by Gary Goldman's Playboy magazine collection. Don used the magazines for reference, as well as partial inspiration from Marilyn Monroe.

"I, who had never looked at a Playboy magazine before, was introduced to one by Gary Goldman who pointed out there were several provocative pictures within, and that they may inspire us.

There was a lot of the Marilyn Monroe image that came across with Daphne. She was a cliche of the dumb blonde. She may not work today, because you know the women have to be able to wield the sword too."
Contributed by CLXcool
In the Amiga version of Dragon's Lair, the copy protection coder of the game left a message to crackers that apparently worked. The message says:

A message to crackers: Nobody wants copy protection. All it is designed to do
is give a program a fighting chance. Now we realize that there is a great
competition to see which group breaks this game first, however, if you do
break it, please consider this: If you let this game out early after release,
and there are few sales, it will be very difficult to justify followup games of
this type. Nobody benefits; not the developers, not the users, and not the
Amiga community. Please reconsider holding on for a while and not letting
the game suffer. The decision is yours.
Contributed by SonicManEXE
During the games early prototypes, Dirk used to be able to exit through many different ways in certain rooms. For example, on the Castle Vestibule scene, Dirk could either exit through a trap door, the left door, or the right door.
Contributed by NERDm NERDf
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A number of scenes were changed between the early prototype and the final release. For example, in the mausoleum section there were originally no skulls jumping out at Dirk, and no skeletal hand trying to grab him. He simply walked down the corridor, but could be directed to exit through any of the doors to the left or right, with some containing Crypt Creeps. He could also exit through the door at the end of the corridor, which is inaccessible in the final version.
Contributed by CLXcool
An animated feature film of Dragon's Lair has been talked about but has never made it off of the drawing board. After the success of the Dragon's Lair video game in the arcades, Don Bluth wanted to make an animated feature based off of the game. The movie was scrapped in 1984.

An animated series of Dragon's Lair was later made, but Don Bluth had no part in making the show other than handing over model sheets of the characters to the people who were developing the show. Changes to the designs were made, and the result of this left Don Bluth later disliking the series.

According to Don Bluth's biography from John Cawley's website, Bluth later developed a story for a Dragon's Lair movie entitled "Dragon's Lair: The Legend". It focused on a teenage Dirk, as well as his origins with Princess Daphne. Dragon's Lair: The Legend followed many different concepts from the game, such as consideration for making Dirk talk, which would later lead to the character being mute due to a spell that was cast upon him.

Don Bluth considered Michael J Fox to voice Dirk for the feature. Don later pitched Dragon's Lair: The Legend to a studio, but they disagreed to go forward with it, thus development for the film was scrapped once again.

In 2013, in an interview with Don Bluth on the 30th anniversary of Dragon's Lair, Don announced that he would consider bringing back the Dragon's Lair movie as a Kickstarter project.
Contributed by CLXcool