Goofs

In the beginning when Bill and Ted are leaving class, the writing on the blackboard clearly says "Ghenghis Khan". A few seconds later it says "Genghis Khan".

People endlessly swap places in the ever-expanding phone booth. Sometimes they disappear altogether.

When the phone booth lands at the Circle K for the first time, the antenna on top of the phone booth falls off. It re-appears in the next scene.

After the "gum and cans" repair to the booth's antenna, some later shots of the booth show an undamaged antenna. It's most noticeable in the "Circuits of History" and the presentation at the end of the film.

In the saloon fight when Billy the Kid is caught cheating at cards, a prostitute swings in on a rope and takes a guy through a window with her. The rope she swings on disappears and re-appears a few times between shots.

Beethoven is picked up by the dudes in 1810. By that year, the real Ludwig van Beethoven was almost completely deaf. Yet Beethoven responds to speech and listens to music at several points of the film.

Dan Shor is too old to be playing Billy the Kid who didn't live to the age of 25.

Bill and Ted introduce Rufus to themselves, but Rufus never told them his name. On the other hand, they introduce Rufus to their younger selves, so the younger selves already know his name when they "circle in time" and get back to the "Circle K" becoming "older selves" and introduce him to their younger selves (it's a time-loop paradox; see trivia).

When the phone booth is formed, the reflection of it in Rufus' glasses is clearly a photo; the text at the top is not reversed.

When the historical dudes are filing into the phone booth at the end of the movie, a trapdoor in the back is visible as they go through it.

When the two sets of Bills and TEds meet for the first time in front of the Circle K store, Bill's right hand slightly disappears into the matted shot when he steps forward and swings his right arm forward towards Bill and Ted that are standing on the left side of the screen.

When the two sets of Bills and Teds meet for the first time in front of the Circle K store, Bill's right hand slightly disappears into the matted shot when he steps forward and swings his right arm forward towards Bill and Ted that are standing on the left side of the screen.

There is a heinous number of most egregious anachronistic errors in the depiction of the famous historical dudes, their lives, their works, their time periods, and their hearing capabilities.

When the dudes pick up Socrates in 410 BCE, the buildings of Athens are stark white ruins. At the time, they were active buildings, painted in bright colors.

The 15th-century warlord orders that the spies be executed in the Iron Maiden, which Bill and Ted take to mean Iron Maiden. This "medieval instrument of torture" was invented in 1793 for display in museums.

During the water slide sequence, Napoleon appears to be wearing modern underwear underneath his historical undergarments.

When Bill and Ted tell Socrates in his original time, 410 B.C., that they're dust in the wind, Socrates says, "Yes! Like the sands of the hourglass!" The hourglass was first introduced to Europe in the 8th century AD. (It's an in-joke about Days of Our Lives (1965).)

When Bill reads the assignment to Ted, he says, "Express to the class how an important historical figure from each of your time periods would view the world of San Dimas, 1988." His lips actually say, "San Dimas, 1987". The "1988" was dubbed later because of a delay in the movie's release.

When Bill and Ted arrive in New Mexico, the phone booth lands in front of a Saguaro cactus, which does not grow naturally in New Mexico.

Captain Logan finds Bill & Ted's tape recording and immediately assumes that it has something to do with the characters in his holding cells, instead of a dumb prank by his son and his son's friend as they would have done growing up. As far as he knows, they don't have anything to do with those characters.

Rufus must help Bill and Ted pass their World History project so that they can become musician together. However, this obstacle is not the result of any time traveling, and in the future that already did become musicians, meaning that they must have already passed the project.

In the Steadicam shot inside the jail, as the camera leads to Freud, the boom mic drops in and out of the shot just before the angle changes.

When Bill and Ted pick up Genghis Khan in Outer Mongolia, the screen card says it's 1209. During the report, Bill says they picked him up in 1269. Genghis Khan died in 1227. In 1269, the Mongol Empire was ruled by Kublai Khan, Genghis' grandson.

During Bill and Ted's presentation, Lincoln speaks with a deep, resonant voice. In reality, Abraham Lincoln's voice was quite high-pitched.

During their report, Bill and Ted say that Joan of Arc drove the English out of France and had the Dauphin crowned by the time she was 17. Joan was 17 when she began her career and had the Dauphin crowned. The English were driven out in 1453, the year France won The Hundred Years' War.

When Bill and Ted land in the future, they tell Billy the Kid and Socrates to stay put. Socrates nods in understanding. In Greece, nodding means no and shaking one's head means yes.

Napoleon looks at and tries ice cream as if he's never seen it before. In reality, Catherine de Medici introduced the French to ice cream when she married the future King Henri II over 250 years before Napoleon's reign. Napoléon Bonaparte more than likely had ice cream before his time travel to San Dimas.