The cyclops states that fire mares can travel a thousand leagues in a day. A league was defined as the distance that a heavily armed man could travel in an hour, and was generally taken to be somewhere between three and four miles. This gives the fire mares an average range of about 3,500 miles in a day, at an average speed of about 146 miles an hour.
According to Special Make-up Designer Nick Maley, the special effects character of the Beast was "the first self-contained animatronic suit... providing not only facial movement but also lung, heart and body-fluid movement all without a single external cable!" while "The Emerald Sear transformation puppet, which was intercut with a non 3-D transformation make-up, attracted the welcome attention of the great (Special Make-up Effects Artist) Dick Smith".
For nearly four weeks, the cast and crew moved to Pinewood Studio's biggest stage used for the James Bond adventures, the "OO7 Stage", which measured 336' x 139' x 40'. Transformed into an eerie and clammy swampland, dotted with jagged trees and foaming eight-foot-deep pools, this ominous landscape of browns and yellows took over five months of construction. The special effects department created a superbly realistic quicksand mire in which some twenty unlucky technicians at one time or another found themselves. Director Peter Yates had to balance himself on a raft which floated on one of the many pools to survey the massive set. Particularly difficult shots demanded the camera operator don a wet-suit and immerse himself in either "quicksand" or one of the larger pools.
Frank Price, then-president of Columbia Pictures, determined that an unknown American actress would help state side ticket sales as opposed to an unknown English actress. With that logic in mind, Price met with Lysette Anthony and informed her that all of her dialogue had been dubbed by actress Lindsay Crouse. Anthony was totally unaware that her voice was to be dubbed prior to the meeting.
Several games were developed and released as promotional tie-ins with the picture. These included two Parker Brothers games, a card game and a board game; a home video game developed for the Atari 5200 SuperSystem, but because of low sales, this was changed to the Atari 2600 video game console platform; and a 1984 arcade game, Krull (1983) manufactured by D. Gottlieb & Co., a Columbia Pictures Industries Corporation company, the producers of this film, who also developed a never released "Krull" pinball-parlor game.
A hand that could physically transform into a "Changeling Claw" was developed for the movie, but due to time constraints, could not be developed in time, and was not used in the film. But the piece later was completed for Tobe Hooper's movie Lifeforce (1985).
Many movie posters for the film featured a long preamble that read: "Beyond our time, beyond our universe . . . there is a planet besieged by alien invaders, where a young king must rescue his love from the clutches of the Beast. Or risk the death of his world. KRULL. A world light-years beyond your imagination".
Within weeks of the start of principal photography, the wardrobe department evolved into a showcase of over a hundred different costumes, ranging from iridescent wedding gowns to tattered suede and leather riding apparel. Daggers, swords, cross-bows, crates of emerald-colored stones, crystal hour-glasses and countless other items, many of which defied classification, filled every shelf and corner of the prop rooms.
The movie has been rumored since around 1980 to have been going to originally to have been made to tie-in with the role playing game of Dungeons & Dragons (1983) [D&D] and be known as "Dragons of Krull" of which a screenplay was being written around this time. According to E. Gary Gygax, "to the best of my knowledge and belief, the producers of Krull (1983) never approached [game publishing company] TSR [the publisher of D&D] for a license to enable their film to use the D&D game IP and did not draw inspiration from the game IP".
Stunt Coordinator Vic Armstrong scoured all over the United Kingdom for sixteen Clydesdale horses to purchase, and then train. Moreover, horses from the Queen's Household Cavalry, near Buckingham Palace, were borrowed and brought to the studio's back-lot.
Prior to the departure of the cast, and the majority of the crew to Italy, sixteen Clydesdale horses, accompanied by eight grooms, were led into three large trailers, and began a long overland trip from England to filming locations in the Abruzzi Mountains in central Italy. Before boarding the Dover ferry, that would transport the equines to France, a passport for each horse had to be presented, which caused a sensation at the customs crossing point, as each passport contained two photos, one a "before make-up" shot, and one an "after make-up" shot.
There is a real-life "Glaive" weapon, but it is different to the fictional one seen in the movie. The European pole-arm weapon has only one single-edged blade (instead of five for the film one) on the tip of a pole and it has been likened to a Chinese Guandao or Japanese Naginata.
A cavernous grotto, glistening gems encrusted in its walls, was a welcome set after two bitterly cold nights of filming in Black Park, the sprawling, forest-like reserve near Pinewood Studios. There, production designer Stephen B. Grimes had created from wood, plaster, stones, and glass, a fanciful home for a clairvoyant who pursues his visions by setting into motion a large, glowing emerald. While the art department was busy spreading fine-ground silver glass on the floors and spreading emerald-colored stones, the special effects department was rigging a large green stone which would rotate in mid-air. Wind machines were also installed to create the powerful gust that disrupts a holograph of the Beast's fortress after the clairvoyant had it called forth for Colwyn and Ynyr to see.
For the final month of principal photography, the production unit moved to locations in Italy to film exterior sequences. Via the traveling matte process, they also secured "plates" to facilitate sequences shot against a bluescreen at Pinewood Studios.
When the film was released on the big screen and on VHS in New Zealand, it was given a G-rating, despite its violence and frightening scenes, and when it was released on DVD, it was still rated G. However, in the UK and in the U.S., it was rated PG.
In Italy, while the main unit followed the movement of Prince Colwyn and his army across the planet of Krull, the special effects model unit was filming the burning of Krullian villages and establishing shots of Prince Colwyn and his father, King Turold, arriving at the White Castle.
Film contains several obvious similarities to The Lord Of The Rings, such as the Dark Lord's evil Eye, the magical sword-weapon like Sting, the sinister guards reminiscent of the Black Riders, the giant spider and web like Shelob, etc.
Following almost a year of pre-production, which saw Peter Yates meticulously storyboarding, Production Designer Stephen B. Grimes sketching hundreds of set ideas, Visual Effects Supervisor Derek Meddings experimenting with elaborate combinations of opticals, and scores of construction workers building fantastical landscapes, Krull (1983) began production in early 1982.