** Most times when they need extra guinea pigs they turn to the crew, but for larger groups and very specific requirements they have been recruiting fans from Twitter. Subverted in that it's not much of a contest, usually the first X number who meet the requirements (and get their paperwork in on time).
** "No Pain, No Gain": Men, women who have never given birth, women who had given birth without epidural, and redheads were recruited to test pain tolerance. Recruits needed to be over 18 and in good health (without chronic pain).
** "Hair of the Dog": Approximately 200 fans formed a crowd to test myths about how to fool a sniffer dog. Recruits needed to be over 18 and free to stand around all day for filming.
** In one episode a few years back, four kids who won a Discovery-sponsored science competition got to be in an episode of ''[=MythBusters=]''.
** While not strictly a ''[=MythBusters=]'' cameo, Adam and Jamie used the 150,000-strong crowd at the [[Series/TheDailyShow Rally to Restore Sanity]] [[Series/TheColbertReport (and/or Fear)]] to test whether a large-enough crowd jumping simultaneously could cause an earthquake on national television. [[spoiler:Busted. Although it had the strength of 100 35-mph car crashes.]]
* DyeHard: Kari is actually more of a brunette and in some episodes her natural hair color can be seen (such as in the pilot).
* EditedForSyndication: The "rough cut" of each episode is about 52 minutes long, but in the US, those episodes get edited down to 42-45 minutes. Most of the cut material winds up on the website. In one first-season episode, most of the "Octopus Pregnancy" segment (including ''all'' the testing) was chopped out of the US release. Adam has said that the US versions of the episodes tend to cut out the punchlines of his jokes.
* ExecutiveMeddling: Largely averted. The Creator/DiscoveryChannel executives give the [=MythBusters=] a ''lot'' of creative freedom and basically let them call the shots. The only times they step in to block a test is really when they feel that the test might offend their sponsors or provoke legal action. The channel's insurance agents have also squashed or put serious restrictions on a lot of tests due to safety concerns for the crew. Or perhaps it would be more accurate to say concerns for the hosts. They once vetoed Adam doing a stunt, but they were fine with Tory doing it.
** This includes one that actually ''jeopardized a myth they were trying to do.'' They were trying to see if a car could be turned over and flung into the air by the wind generated by a jet engine. The company that had loaned them the jet took it back due to them being worried that something might hit the plane and damage it, despite the fact that the car would be moving ''away from the plane.''
*** They eventually found an airline who agreed to lend a plane to perform this very experiment (even after a test firing of the jet's engines ''tore up the runway'' they were testing on--the owner basically shrugged after seeing it, and let testing continue), which they tried on a car, a school bus and a small airplane. And it was ''awesome.''
** Early in the show's history, Discovery execs pushed for Jamie and Adam to have ''Series/AmericanChopper''-style DocuSoap arguments on camera. There's a couple episodes where this made it into the finished show (the Quicksand episode notably), but the two of them finally told the execs no, that behavior wasn't professional, and they weren't going to do it any more.
** Played straight at least one time (though not shown on the show itself). Basically, they were going to do experiments on how easy it is to hack RFID chips, and per policy, called up the manufacturers (Texas Instruments) to schedule a conference call to talk about it. When they actually sat down to the scheduled call, lawyers from most of the larger credit card companies were involved, saying they were not to do the episode. Discovery could not afford to lose the advertising, and they had to cancel the episode. You can see Adam explain it at The Last Hope hacker conference [[http://www.youtube.com/watch?v=X034R3yzDhw here]].
*** The Build Team would lampshade the situation while discussing the results of the "RFID in a MRI" myth in the Myth Revolution episode, with Tory commenting on how the chips ''should'' be put to the test, with Grant retorting that they're [[FictionasCoverup already on too many government watch lists]] for it to be worth the trouble.
** When the [=MythBusters=] tested whether sugared cereal was less nutritious than the box it came in, their original approach was to use mice (one group was given the cereal and another cardboard pellets, with a third group given "regular" mice pellets as a control). They returned after a weekend away from M5 to find that one mouse in the cardboard group had decided [[ImAHumanitarian to get nutrition from its brethren]] instead of the cardboard. The [=MythBusters=] thought [[BlackComedyCannibalism this was hilarious]], but the Discovery suits were [[DudeNotFunny not amused]], and forced them to cut that particular test from the episode. Watch Adam discuss the situation [[http://www.youtube.com/watch?v=ziQWDnFSPt8 here]].
* FunnyCharacterBoringActor: The main reason Jamie brought Adam in on the show is because he is naturally TheStoic and uninteresting by himself. Adam's high energy level and their good working relationship manages to mask this on camera, but they've also said the editing makes Jamie seem more quick-witted and eloquent than he really is.
** [[Series/GoodEats Alton Brown]] recently appeared in a food-centric episode, helping the main duo with three myths (two in the episode, one on the website).
* [[HeyItsThatSound Hey It's That Music]]: Sharp-eared gamers may recognize one of the musical snips they sometimes use between shots as coming from the soundtrack of ''VideoGame/MechWarrior 2''.
** The 100th episode was celebrated by testing a bunch of stunts from ''Series/MacGyver''.
** The 10th anniversary was celebrated with a [[CallBack revising]] of the JATO myth. [[spoiler: And finally definitively busting it.]]
* MissingEpisode: A lot of general footage and some mini-myths are left out of the show, many of which they put on their website; the show then invites viewers to visit said site to see what was left out.
** One famous myth, though, was actually kept from airing at all because it was deemed a little too risque/immature. It involved the flatulence myths and testing if you can actually set your farts on fire. Confirmed, but most of the footage is of Adam spread eagle on a specialized chair holding a lighter near his crotch. Nobody really wants to see that. They finally did the experiment on an episode of [[Series/TheLateLateShow Craig Ferguson]] which the cast were guests on. It worked. The segment itself finally partially aired during the "25 Best Moments" special.
** And at a live Q&A three years ago, Jamie mentioned that they once tested the myth of whether a cardboard cereal box was more nutritious than the cereal itself. The test as a whole did air, but one experiment which was cut involved feeding three mice cardboard pellets with a little sugar-free sweetener for taste. The next day Adam and Jamie, instead of finding three mice, discovered one fat mouse (and some remains)... Discovery Channel (or the producers) decided not to air the footage so the Q&A is the only way fans learned of it.
** The footage from the errant cannonball incident will not be released, in accordance with the wishes of the family whose house said cannonball went ''through''. The myth itself aired in late 2012, but was preceded by a short commentary by Grant, Kari and Tory explaining what happened. They showed the build-up to the incident and showed the cannon being fired, but did not show the aftermath. Then, the team explained what had happened afterwards and then the episode showed them continuing the myth months later at a remote quarry where there was no risk of a repeat of the incident.
** Plans were in place to do an episode about RFID tags, with research already underway. Legal counsel for every credit card company in the world explained to them exactly how much it wasn't going to happen, and it's never going to happen.
** The Mailbag Special was another instance, like the above-mentioned "lighting farts on fire" myth, where previously unaired footage was finally shown, this one concerning a myth that a van filled with flammable gases could blow up when someone used a keyless remote. The myth never made it to air because it was confirmed ''too quickly'' -- the team went straight to a full-scale test and immediately blew the van up with the remote, leaving no need for small-scale tests or replicating the results through other means. They didn't believe it would work so well, but Grant's comment really should've tipped them off.
--->'''Grant''': [[ItsQuietTooQuiet It's quiet out there. Almost too quiet]].
** Another clip from the Mailbag Special showed more unaired footage from the flatulence episode, exploring the myth that girls don't pass gas (not surprisingly, this was busted).
** The entire [[SexSells Laws Of Attraction]] episode seems to have simply vanished.
** As has "Plane Boarding/Bite the Bullet." Both of these episodes as well as a third investigating the fastest way of navigating traffic were removed due to a copyright lawsuit.
*** All three (Laws of Attraction, Plane Boarding, and Traffic Tricks) ''finally'' aired in the US in August 2014. The last two had previously aired overseas.
* NeverWorkWithChildrenOrAnimals: A few cases with children, such as the "Taking Candy from a Baby" myth (turns out crying is one of the baby's greatest defenses) and plenty with animals, such as the goats they couldn't get to faint (though one did [[GroinAttack punch Tory in the balls]]), the skunks they couldn't get to spray them, and the crocodiles they couldn't get to chase them. Their experience with uncooperative ducks while trying to see if a duck's quack really has no echo is also an example, resulting in a recurring clip of Jamie holding a duck in a threatening manner.
--> "Quack, damn you!"
* NoExportForYou: Inverted. Though the show is made in America, the episode "Plane Boarding"/"Bite the Bullet" aired overseas two full years before it finally aired in the United States. A few other episodes were similarly delayed (including Traffic Tricks), though no others were delayed for that long.
* OfficialFanSubmittedContent: Most of their myths to test are now from fans, as are ideas of what to re-test.
** Unfortunately, on November 7, 2012, Discovery shut down all show discussion forums, including Mythbusters', and with the unofficial fan site having been shut down several years ago due to "creative differences", there is [[http://citadelofmyths.freeforums.net/index.cgi one fan site]] used by researchers for myths, but is largely unknown, for whatever reason.
** The Mythbusters "Submit A Myth"/discussion page has been officially reinstated [[http://dsc.discovery.com/tv-shows/mythbusters/show-talk/beyond-duct-tape.htm here]], via a Disqus comment feed.
* OldShame: Adam's biggest acting role is revealed to be: a teenage stockboy in a toilet paper commercial. That and a Billy Joel music video.
** Adam Savage has actually used the word 'trope' on the show. He also has a bit of a tradition of going to conventions in concealing cosplay so nobody knows who he is; among others, he's gone as No-Face from ''Anime/SpiritedAway'' and a [[Film/TheLordOfTheRings Nazgul]]. He also owns a replica [[http://dsc.discovery.com/show-news/adam-stark.html#mkcpgn=fbdsc17 Mark 1 Iron Man armor suit from the movie]] which he got on [=eBay=]. He is a honorary member of the 501st[[note]]a ''Franchise/StarWars'' stormtrooper cosplay troupe[[/note]], according to the "Revenge of the Myth" episode.
** Grant has gone to numerous conventions. He even dressed as [[Series/DoctorWho the Tenth Doctor]] at some point.
* TheOtherDarrin: Occasionally, the team will pass off one of the Simulaids as Buster for some unexplained reason.
* ThePeteBest: Scottie Chapman left the Build Team just when they got a bigger role on the show, and was replaced by Grant Imahara.
* StarMakingRole: A few years into the show now, Adam and Jamie are big draws as speakers and have hosted a booth at Comic Con at least once. Failing that, they are fairly recognizable to most people, if not by name, at least as "the [=MythBusters=]".
* WrittenInInfirmity: Kari's pregnancy and ensuing maternity leave during the 2009 season.