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.

Moments later, Planktonamor's dragon kidnaps Princess Pearl, and King Krabs begs SpongeBob and Patrick to rescue her, who gladly accept along with Squidly.

"Dunces and Dragons" was written by Zeus Cervas, Erik Wiese, and Tim Hill, with Alan Smart and Tom Yasumi serving as animation directors.

It's fun to watch SpongeBob in a suit of armor riding a seahorse, and bringing karate to the Middle Ages.

[4] The game segments were replaced with themes and characters from the episode such as Jellyfish Joust and Slimy Sword Battle.

"[4] Prior to the premiere Nickelodeon also aired a SpongeBob marathon from 4:00-8:00 p.m., showing episodes with hero themes.

[7] To enter, participants wrote a 25-word adventure story for the chances of winning a trip to England, Spain, Germany, or Mexico.

Other prizes included a family trip to Orlando at the Nickelodeon Hotel, and a SpongeBob SquarePants: Lost in Time DVD.

"[9] Nancy Basile of About.com compared the episode to the then-television film of the series called SpongeBob's Atlantis SquarePantis.

"[16] Speaking less positively of the special, technical director (now showrunner) Vincent Waller, in response to a question on Twitter asking what his least favorite episode of SpongeBob was, stated in 2017, "I'm not fond of the one where [the characters] go back to the time of Knights of old.