"Dunces and Dragons" (also known as "Lost in Time") is the sixth episode of the fourth season of the American animated television series SpongeBob SquarePants, and the 66th episode overall. It was written by Zeus Cervas, Erik Wiese, and Tim Hill, and the animation was directed by supervising director Alan Smart and Tom Yasumi; Cervas and Wiese also functioned as storyboard directors. The episode originally aired on Nickelodeon in the United States as a half-hour special on February 20, 2006.

In the episode, SpongeBob and Patrick travel back in time, where they find that Mr. Krabs' ancestor is the ruler of the kingdom, which is being attacked by an evil wizard known as Planktonimor. SpongeBob and Patrick, assisted by Squidly and the Dark Knight, ancestors of Squidward and Sandy, must rescue the daughter of King Krabs, who has been captured.

Tie-in promotions were made with Burger King, which released a series of toys based on the episode. "Dunces and Dragons" was the most successful of the season, drawing 8.6 million viewers, and was met with positive reviews. It was also elected as the third most-voted episode on the "Best Day Ever" marathon, behind "Karate Island" and "Wishing You Well", episodes from the same season.