The season follows the adventures of Finn, a human boy, and his best friend and adoptive brother Jake, a dog with magical powers to change shape and size at will.

This season saw the series grow and progress, featuring the first of the popular Fionna and Cake episodes, as well as marking the first time that fan-submitted content was canonized.

Ward also noted that the storyboard artists affected the overall tone of the show, moving it towards more bizarre and spiritual matters.

The season was storyboarded and written by Ako Castuera, Tom Herpich, Adam Muto, Rebecca Sugar, Jesse Moynihan, Bert Youn, Kent Osborne, Somvilay Xayaphone, Pendleton Ward, and Natasha Allegri.

[1] This season expands upon the backstories of Marceline and Ice King,[2] and concludes with Finn attempting to understand his attraction towards Bubblegum and developing a crush on newly introduced Flame Princess.

[a] The premise of this episode is that the Ice King has created a fan fiction wherein all the main characters of Adventure Time appear in the opposite gender.

The genesis for the episode were drawings that storyboard artist Natasha Allegri posted onto the internet during her free time.

[9] The episode had a sequel during the fifth season, focusing on Marceline's male counterpart, Marshall Lee, who is voiced by Donald Glover.

[16][17][18] The season was storyboarded and written by Ako Castuera, Tom Herpich, Adam Muto, Rebecca Sugar, Jesse Moynihan, Bert Youn, Osborne, Somvilay Xayaphone, Ward, and Allegri.

[b] Pendleton Ward referred to many of the writers during the third season as "really smart, smartypants people" who were responsible for inserting weirder and more spiritual ideas into the series.

[6][19] The voice actors for the season include: Jeremy Shada (Finn the Human), John DiMaggio (Jake the Dog), Tom Kenny (The Ice King), Hynden Walch (Princess Bubblegum), and Olivia Olson (Marceline the Vampire Queen).

Former storyboard artist Niki Yang voices the sentient video game console BMO, as well as Jake's girlfriend Lady Rainicorn in Korean.

[29][30] "Conquest of Cuteness" also marked gains when compared to the same timeslot a year prior; growth in kids and boys aged 6–11, 2–11 and 9–14 ranged between 13 and 40 percent.

[32] The season finale, "Incendium", aired on February 13, 2012, ranked as the number one telecast of the week among boys aged 6–11 on all of television.

[34] In his review, LeChevallier wrote that the series "scores relatively high marks for storytelling, artwork, music, voice acting, and realization with its neatly wrapped, 11-minute packages of multicolored awesomeness.

[38] The episode "Thank You" was also purposely screened in a movie theatre so that it could qualify for the Academy Award for Best Animated Short Film.

Warner Home Video released multiple DVD volumes, such as It Came from the Nightosphere, Jake vs. Me-Mow, Fionna and Cake, The Suitor, Princess Day, Finn the Human, Frost & Fire, and The Enchiridion which contain episodes from the third season.

[62][63][64][65][66][67][68][69] All DVD releases can be purchased on the Cartoon Network Shop, and the individual episodes can be downloaded from both the iTunes Store and Amazon.com.