In Venice Beach, naive Midwesterner JB bonds with local slacker KG and they form the rock band Tenacious D. Setting out to become the world's greatest band is no easy feat, so they set out to steal what could be the answer to their prayers... a magical guitar pick housed in a rock-and-roll museum some 300 miles away.
Amiable slackers Bill and Ted are once again roped into a fantastical adventure when De Nomolos, a villain from the future, sends evil robot duplicates of the two lads to terminate and replace them. The robot doubles actually succeed in killing Bill and Ted, but the two are determined to escape the afterlife, challenging the Grim Reaper to a series of games in order to return to the land of the living.
Bill and Ted are high school buddies starting a band. They are also about to fail their history class—which means Ted would be sent to military school—but receive help from Rufus, a traveller from a future where their band is the foundation for a perfect society. With the use of Rufus' time machine, Bill and Ted travel to various points in history, returning with important figures to help them complete their final history presentation.