* BannedInChina: The film was heavily censored in the UK to remove scene involving nunchucks, which were banned at the time.
** The hundreds of extras needed to play derelicts were real derelicts from the streets of Hong Kong.
** There was a problem finding actresses to play prostitutes, so real prostitutes were hired for the film.
** Lee, played by Bruce Lee.
** Ditto in the first Mexican Spanish dub, when he was voiced by Hector ''Lee''.
** In an inversion, actor Yang Zse took the stage name of Bolo Yeung to cash in on his sudden exposure in this film as the villainous Bolo.
* DirectedByCastmember: Creator/BruceLee directed the film's opening Shaolin Monastery fight sequence.
** In the original script, [[spoiler: Roper dies and Williams survives.]] This was reversed by John Saxon's agent to land him a bigger part; it was ''not'' an example of racist executives.
** Lee, playing a secret agent, wanted to use a gun in at least one scene. See WhyDontYouJustShootHim on the main page.
* FatalMethodActing: Averted: Peter Archer almost drowned filming the 'fighting without fighting' scene.
* FollowTheLeader: Pretty much all FightingGames and movies involving a fighting tournament owe at least something to this film.
* HarpoDoesSomethingFunny: In the finished screenplay, there were no details of what was happening in the action sequences. They would be written as 'They will be choreographed by Mr. Creator/BruceLee'.
* HostilityOnTheSet: Fights broke out onset between stuntmen and extras hired from rival families of Triads.
* InternationalCoproduction: The film was a collaboration between Creator/WarnerBros and Creator/GoldenHarvest as a way of bringing martial arts films to the west.
* LoopingLines: The entire movie was filmed without sound, and so virtually all the actors had to loop their dialogue after filming was complete, with a couple of exceptions:
** Kien Shih (Mr. Han) spoke no English, so his voice was dubbed by veteran Chinese-American actor Keye Luke (of ''Series/KungFu'', ''Franchise/StarTrek'', ''Gremlins'', and ''Film/CharlieChan'' fame).
** When the extended Cantonese/Mandarin versions were released for the first time in English in 1998, some extra dubbing had to be done, because no English dialogue existed at that time for those scenes. One of the scenes involved Roy Chiao (Shaolin Abbott) and Bruce Lee. Chiao was still alive (he died shortly thereafter), and was able to dub himself, but Lee's voice was supplied by Bruce Lee biographer John Little. Luckily, Lee's real voice was left alone for the scenes that originally used it.
* RealLife/MeanCharacterNiceActor: Shih Kien made a career out of playing various antagonists, most notably Han, but he and Creator/BruceLee got along pretty well off the set. Probably why he got the part.
** The praying mantises were flown in from Hawaii. When they arrived, they refused to fight.
** The crew had a very difficult time getting the cat to sit still on the guillotine.
** When Creator/BruceLee held the poisonous snake that guarded the secret entrance to Han's drug lab, the snake bit him. Fortunately, the snake's venom gland had been removed.
* NoStuntDouble: The only times Creator/BruceLee was doubled for the scenes where he was required to do backflips.
* TheOtherMarty: Jim Kelly replaced Rockne Tarkington, who quit the film three days before production was due to star because he thought the pay was too low.
* RealLifeRelative: Linda Lee Caldwell, Creator/BruceLee's wife, has a short cameo as a partygoer at Han's banquet. She appears in a purple dress and is walking around among the banquet servers and entertainers.
* ThrowItIn: In the scene where O'Hara (Robert Wall) is beaten by Lee, Lee delivers a flying kick to O'Hara. Wall and Lee had decided that Lee should deliver a real flying kick to add authenticity to the scene, as Wall knew how to take the hit. They had not planned for Wall to go flying back into the extras, knocking them all over and actually breaking one's arm.
* UnintentionalPeriodPiece: The leisure suits, turtle necks, the funky music, Williams' afro and [[JiveTurkey manner of speech]] along with mentioning that the UsefulNotes/VietnamWar was only a few years ago, all point to this movie being in TheSeventies. Also, this movie is mostly responsible for kick-starting the kung-fu craze in the US during this time.
* WorkingTitle: ''Blood and Steel''.
* The line "We have been waiting for you" is familiar to fans of the original ''VideoGame/MortalKombat'' arcade game.