On the night it aired, it ranked as the number one telecast of the day in the Nielsen ratings among boys aged 2–11. "Card Wars" first aired on Cartoon Network on July 16, 2012. Cash in particular posed out all of the moves to make them faithful to real life. Many of the scenes with BMO were inspired by Erik Fountain and Cash's experiences skateboarding. He messaged both Youn-who, at the time, was in South Korea-and Ward via Facebook to inform the two that he enjoyed the episode so much. Nate Cash served as the episode's creative director. However, it took until the fourth season for the episode to be made. Originally, it had been planned to make the episode during the first season because McHale and Ward were actively playing immersive, worldbuilding games. Storyboard artist Rebecca Sugar noted that the idea behind this episode had been in development for a long time. Ward later noted, in the DVD commentary for the third season episode "Another Way", that "Card Wars" featured Youn's most extreme and exaggerated faces. Ristaino revealed that he drew at least three of these faces for the episode. These faces necessitated lead character designer Andy Ristaino to drew several unique, key frames, colloquially known as "Bert Youn Specials". During the middle of the episode, both Finn and Jake are depicted with grotesque, off-model faces, a trademark of Youn's storyboarding style.
The episode was directed by Larry Leichliter.
"Card Wars" was written and storyboarded by Bert Youn and Somvilay Xayaphone, from a story developed by series creator Pendleton Ward, Patrick McHale, and Kent Osborne. The episode ends with the two brothers happily sharing the nasty drink, seemingly on friendly terms again. Finn is forced to drink the disgusting liquid concoction, but manages to trick Jake into trying it. Once the game resumes, Finn purposely sacrifices his all-powerful Pig, allowing Jake to defeat him. Finn, therefore, decides to purposely lose the game for Jake's sake. Soon, however, Jake becomes angry and aggressive, and Finn is warned by BMO (voiced by Niki Yang) that if Jake loses, he will become bitter and depressed. Time and time again, Jake tries to kill Finn's Pig, only for his plans to backfire. However, once the board game component begins, Finn gains the upper hand, largely by “flooping” (or “activating”) his Pig card. Jake explains the complex and arcane rules to Finn, who quickly falls asleep. Jake explains to Finn that his girlfriend, Lady Rainicorn will not play his favorite card game, ‘’Card Wars’’ Finn, however, agrees to play with Jake, and the duo agree that the winner (who will be crowned "the Cool Guy") will be rewarded with soda, whereas the loser (who will be dubbed "the Dweeb") will be forced to drink a terrible concoction including soda, coffee grounds, and kimchi, among other things. Due to the episode's success, a mobile app and a physical version of the eponymous game have been released. Club applauding how the eponymous game lampooned Magic: The Gathering, Dungeons & Dragons, and Risk. The episode received largely positive critical reviews, with Alasdair Wilkins of The A.V.
It had originally been planned to produce the episode during the first season because McHale and Ward were actively playing immersive, worldbuilding games. But things take a turn for the worse when Jake becomes overly competitive. In this episode, Finn and Jake play Card Wars, a tabletop game. The series follows the adventures of Finn (voiced by Jeremy Shada), a human boy, and his best friend and adoptive brother Jake (voiced by John DiMaggio), a dog with magical powers to change shape and grow and shrink at will. It originally aired on Cartoon Network on July 16, 2012. The episode was written and storyboarded by Somvilay Xayaphone and Bert Youn, from a story by Patrick McHale, Kent Osborne, and Pendleton Ward. " Card Wars" is the fourteenth episode of the fourth season of the American animated television series Adventure Time.