In 2688 San Dimas, California, a man named Rufus describes his Utopian society, which owes its perfection to the two “Great Ones,” Bill S. Preston and Ted “Theodore” Logan, who lived seven hundred years before. Rufus recounts that he was once sent back in time to help Bill and Ted secure an idyllic future for San Dimas. Back in 1988, dimwitted teenagers Bill and Ted practice guitar in Bill’s garage and discuss the future of their band, Wyld Stallyns. At school, the boys’ History teacher, Mr. Ryan, warns that Bill and Ted will fail his class if they do not receive perfect scores on their oral report the next day. Re-reading their assignment, Bill tells Ted they must discuss how important historical figures would view modern-day San Dimas. After school, Ted goes home to retrieve his books for a joint study session. His father, Police Captain Logan, informs Ted that he will be sent to military school in Alaska if he does not pass Mr. Ryan’s class. Later, the boys study in the parking lot of a convenience store, where Rufus appears in a time-traveling telephone booth and offers to help with their report. The boys marvel at the arrival of a second telephone booth, carrying their doppelgangers, who inform Bill and Ted that they are about to have an “excellent adventure.” The doppelgangers announce that Bill and Ted must continue working on the history report, and urge them to say hello the princesses. Rufus ushers Bill and Ted into his booth and dials the pay phone, activating an antenna. On the way to 1805 Austria, Rufus explains they are traveling through the circuits of time via future technology. The three arrive just after Napoleon Bonaparte’s army has invaded Austria. They are only there momentarily, however, before Rufus insists they must go. Just as the booth begins to dematerialize, Napoleon is sent flying by an explosion and gets sucked into the time machine’s wake. Arriving back in Ted’s front yard, Rufus instructs the boys to use the phone book, Circuits of Time, to navigate time travel on their own. He warns that wherever they go, time will pass normally in the present, and they must deliver their report on time, or else. As Rufus disappears, an empty phone booth materializes. As the boys contemplate what to do next, Napoleon falls out of a tree, and Bill suggests they collect other historical figures to use in their report. The boys leave Napoleon in the care of Ted’s little brother, Deacon, before heading back outside. On the way out, Ted is stopped by Mr. Logan, who accuses his son of misplacing a set of keys and informs him he will be sent to military school the following night. Bill calls Mr. Logan from the pay phone and impersonates a police officer, luring him to the police station so the boys can escape. As they travel through time, their first stop is the Old West, where they find Billy the Kid in 1879 New Mexico. After the Kid incites a barroom brawl, Bill and Ted help him escape an angry mob via the phone booth. The three travel back to 410 B.C., arriving in ancient Greece to find Socrates lecturing on the transient nature of human existence. Mispronouncing his name as “So-crates,” Ted uses rudimentary sign language to communicate with the philosopher and ushers him into the phone booth. Next, they go to Medieval England, where Bill and Ted meet the beautiful princesses their doppelgangers mentioned. Although they try to help the girls dodge arranged marriages, their father, the evil duke, discovers Bill and Ted and orders them executed. Just as the boys are about to be beheaded, the executioners reveal themselves to be Billy the Kid and Socrates. The four narrowly escape the evil duke’s guards, accidentally traveling to future San Dimas, where they meet Rufus’s leaders, “The Most Important People in the World.” Bill and Ted learn that they are worshipped in the future, and offer their followers two bits of wisdom: “Be excellent to each other,” and “Party on, dudes.” Meanwhile, in the present, Deacon and his friends take Napoleon for ice cream, then bowling. Deacon becomes frustrated with Napoleon’s bad attitude at the bowling alley and abandons him there. As their time machine begins to malfunction, Bill and Ted make several more stops, collecting Sigmund Freud, Ludwig van Beethoven, Joan of Arc, Genghis Khan, and Abraham Lincoln. Finally, the group arrives in prehistoric San Dimas, and Bill fixes the antenna on the phone booth with a wad of chewing gum. Arriving back in the present, Bill and Ted take the historical figures to the San Dimas mall to introduce them to the modern world. Leaving the group to their own devices, the boys go to Deacon’s baseball game to retrieve Napoleon, but when they realize he has gone missing, they panic. Assuming he went to the Waterloo amusement park, they find him there and drag him away. Meanwhile, as Mr. Ryan’s other students deliver their oral reports to a packed auditorium, Genghis Khan terrorizes a sporting goods store with a bat, Joan of Arc commandeers an aerobics class, and Beethoven plays a set of keyboards to a rapt audience. Mall cops arrest all of the historical figures and take them to the police station, where Mr. Logan orders them locked up. Bill’s young, attractive stepmother, Missy, drives Bill, Ted, and Napoleon to the police station, where Bill and Ted orchestrate a jailbreak with the help of their doppelgangers, who left Mr. Logan’s missing set of keys behind. They arrive at school just in time. The lights lower as Billy the Kid introduces Bill and Ted, instructing the audience to applaud. Mr. Logan and Mr. Preston argue, each blaming the other’s son for being a bad influence, while Freud onstage demonstrates psychoanalysis by analyzing Ted’s conflicted relationship with his father. Genghis Khan and Joan of Arc show off their fighting skills, and Abraham Lincoln gives a speech in which he urges students to “be excellent to each other” and “party on.” Bill and Ted add commentary about the historical figures’ impressions of modern-day San Dimas before joining them in the phone booth and disappearing back in time. Sometime later, as Bill and Ted practice guitar in Bill’s garage, Ted laments that nothing much has changed in their lives since the excellent adventure. They are interrupted by Rufus, who arrives with the two princesses from Medieval England in tow to congratulate them on passing History class. Rufus asks Bill and Ted to sign a Wyld Stallyns album cover for his children, explaining that their band’s music will eventually end war and poverty and become the foundation of a more peaceful society. He remarks that the princesses are in the band as well, and asks to play some music with the foursome. The amateur band sounds horribly out of tune, and Rufus comments that, in time, they do get better.