Factual error: This happens during the scene when Harry and Lloyd offer the little boy 5 dollars to get them slushies. This movie is set in the 80's but notice the $5 he gives him. It is the newer issued $5 that came out in the 90's.

Revealing: In the scene where Harry and Lloyd first meet by running into each other, when it shows it in slow motion, you can see Lloyd brace for an impact when he's not suppose to know Harry is coming.

Revealing: In the scene where the guys get the flagpole wedgie, we see Lloyd's coat being pulled up by invisible wires.

Factual error: Cheri Oteri takes the class to the museum. When she is tipping the tour guide, she offers her a modern day $5 bill, despite the film taking place in the 80s.

Revealing: When we see the slow motion replays of Harry and Lloyd colliding, you can see that Lloyd's tooth doesn't touch Harry's head. In fact, their heads completely miss each other.

Factual error: When the guys are playing "it" in the Big A store, you can see Dasani and Mountain Dew Livewire - drinks that have only been around a few weeks/years.

Revealing: In the scene where Harry is going to Jessica's house on the waxer, if you watch carefully most likely you'll catch the last person who falls is wearing roller-blades like the kind that look like shoes.

Visible crew/equipment: In the scene where Harry and Lloyd are drinking slushies Lloyd starts to tell Harry "you gotta go fast Harry", right then you can see something black covering up Lloyd's "cracked tooth" proving that it's not cracked.

Continuity: In the scene were Lloyd finds Harry's "treasure chest", you can see that the chest is laying flat against the wall, but when the Principal and the lunch lady come and find it missing, there is a small dirt outline, as if the chest was pointing out from the wall, instead of larger outline, as if it were flat against the wall.

Continuity: When Lloyd is sticking the napkins on himself in the cafeteria, you can see he is wearing underwear under the napkins, while in the next shot he isn't.

Continuity: When Harry and Lloyd first collide, if you look carefully you can see that Lloyd still has his entire tooth when he falls. It was supposed to be chipped.

Revealing: When Jessica is riding in the principal's car they pass a gas station where there is a white late 90's/2000ish van. This film is set in the 80's.

Continuity: When Lloyd is at Harry's window trying to wake up with him, the shards of glass on the windowsill keep changing positions. In the final shot of the scene, they have disappeared altogether.

Factual error: In the scene where Lloyd puts on a record on over the loud speaker to get ready for school in the morning, it plays Ice Ice Baby. This song was first released in 1990, whereas the film's set in the 80's.

Continuity: When Ms. Heller is talking to the tour guide at the museum, she offers her a $5 bill to take the tour twice. How the bill is folded changes. When it is a close-up of Ms. Heller the bill is half folded but when the tour guide is pushing away the bill it is fully folded, then it keeps switching back between folds.

Continuity: When Harry is drinking his Slushy fast, some drips on his neck and leaves a stain. Then, when Jessica comes, the stain is gone.

Continuity: When Lloyd is getting ready for school he is dancing in the halls, showering in the science class, goofing off in the cafeteria and looting the lost and found for clothes. There is no one in the school. You can see light outside and he runs off to hurry up and catch his bus. Don't you think teachers/staff would already be in the building?

Continuity: When the teacher asks her "special needs class" if they have any ideas for a float, the camera switches between people and conversations and every single time this happens the Chinese exchange student changes position (resting on her elbow, arms out stretched, hands together etc...)

Continuity: When Jessica is chasing the bus to the museum, her hubcap comes off after she goes airborne over the hill. It is back on in the next shot.

Factual error: Throughout the movie, Lloyd and Harry often drink Slushees. However, Slushee was not a company until 1999.