• Acceptable Targets: Like all good English TV, France, England and America, (and occasionally Ireland, Scotland, and Wales) are constantly the butt of jokes.
    • Although in the episode about France it was pointed out that the French have a very solid military record, refuting the Cheese-Eating Surrender Monkeys stereotype, and an episode on "Germany" instituted a special "Don't Mention the War" penalty (only for Stephen to go on to break it himself with a question about WWII).
    • Rob Brydon often takes umbrage at what he (jokingly) calls Stephen's offensive stereotypes with regard to the Welsh.
    • Stephen once made the mistake of mentioning his prep-school tailor, with obvious results
  • The Ace: Sandi Toksvig, who wins virtually every time she's on the show and still manages to be very interesting and humorous.
  • The Artifact: Almost no one ever uses the buzzers anymore, even during the General Ignorance round. Jo Brand might be the only exception.
    • The panelists appear to be using the buzzers more now in Series L.
  • Author's Saving Throw: Rob's awful, awful pun "philately will get me nowhere" in Holidays. Cue audience groans and an utterly unimpressed Stephen. Luckily, he redeemed himself by going back in time and correcting himself.
  • Big Lipped Alligator Moment:
    • Alan being presented with a potato-head version of himself in "Corby".
    • At the end of "Justice", after a discussion about nude psychotherapy, all five panelists get out of their seats and get their lads out. Color bars appear and a continuity announcer says something's gone wrong. The show returns to the QI panelists back in their seats, joking about their relative sizes. Unlike other non-sequitur moments intended to segue into the next topic, the only thing left is the reading out of the scores (at least in the regular length version of the show).
  • Crosses the Line Twice: Stephen tells a joke that utilises this in the punchline, and then asks "Why is it so funny?!
  • Dude, Not Funny!: Fry had to cancel a Japanese segment of a documentary about language and culture after poking fun at the bizarre luck of Tsutomu Yamaguchi.
  • Ear Worm:
  • Ensemble Dark Horse: Johnny Vegas. Considered The Scrappy by some fans.
  • Freud Was Right:
    • In one episode, the audience laughed uncontrollably as the formula for paper folding comes up.
      Stephen: What you need is length and thickness (to determine how many times you can fold a piece of paper).
      • This may qualify as a CMOF, as quite a few innuendos had been delivered by that point and Rob Brydon simply gave Stephen an innocent "Oh, really?" look...
    • Not to mention Doon Makichan absentmindedly miming eating a large deep-fried Curly Wurly. Two-handed. Linkski.
  • Harsher in Hindsight: There are many instances during the "J" series where Stephen Fry is obviously sick, on medication or otherwise not himself (the whole Jumpers episode being the most obvious example). Later that year, he attempted suicide (again), and in an interview afterwards talking about his bipolar disorder, he said, "There are times when I'm doing QI and I'm going, 'ha ha, yeah, yeah' and inside I'm going, 'I want to f*** die. I want to f*** die.'"
  • Hilarious in Hindsight:
    • During the "Green" episode, Danny Baker urged the viewers at home to save electricity by turning off their television sets. That episode had one of the lowest audience figures of the programme's run.
    • When David Tennant was on the show jokes were made about Bill Bailey being on the Christmas special of Doctor Who. Come the 2011 Christmas special...
    • In early series, Alan Davies makes several jokes about being an oppressed and displaced Welsh person. And then, in the Europe episode, he reveals that he's found out that, despite his last name indicating otherwise, he actually has no Welsh ancestry.
    • In Series I aired in 2011, when discussing the fungus Cordyceps, Johnny Vegas speculates what kind of disaster it would be if it jumped into humans. Cue The Last of Us, a game featuring that exact premise just two years later.
    • In the Series F episode Future, Ben Miller's buzzer is the Doctor Who theme. Come 2014, and Ben Miller is playing the villain in the third episode of Series 8!
  • Most Annoying Sound: Sean Lock's crying baby buzzer in "Imbroglio". Sure, it was invoked (all the buzzers were purposefully annoying), but while the first two buzzers were annoying in an amusing way, Sean's crossed the line into this territory. Judging by the reactions of Sean (he doesn't often lose his smile, but he did for this!), Stephen, and the audience, they all seem to agree.
  • Nightmare Fuel: The occasional segment, but the "Inventive" episode was pretty horrifying for anyone with a fear of ventriloquists' dummies.
  • The Producers Think Of Everything: Some of the panelists' jokey answers set off the klaxon, especially too-obvious jokes.
    Stephen: Name a poisonous snake.
    Jimmy Carr: Piers Morgan?
  • The Scrappy: