Twelve-year-old Finn battles evil in the Land of Ooo. Assisted by his magical dog, Jake, Finn roams the Land of Ooo righting wrongs and battling evil. Usually that evil comes in the form of the Ice King, who is in search of a wife. He's decided he should wed Princess Bubblegum, though she doesn't want to marry him. Still, he persists in trying to steal her away, and Finn and Jake, along with Lady Raincorn (a cross between a unicorn and a rainbow) do their best to keep her from harm.
- 71245 Level Pack
- 71246 Team Pack
- 71285 Fun Pack
- Breakfast Kingdom:
- What pack unlocks it: 71246 Team Pack
- Pillow World - After Dark:
- What pack unlocks it: 71285 Fun Pack
- Princess Bubblegum
- Ice King
- Tree Trunks
- Magic Man
- Cinnamon Bun
- The Lich
- Choose Goose
- Earl of Lemongrab
- Flame Princess
- Earl of Lemongrab (Clone)
- Lady Rainicorn
- Pillow Dragon
- Land of Ooo
- It's first shown in a teaser of Year 2 which featured the Wicked Witch. It was clear that the background she was in was from Adventure Time.
- This is the first franchise in Year 2 to have a Level Pack, a Team Pack, and a Fun Pack.
- It's also the first franchise overall, to have said combination of packs, with all the others, either having fun packs and a team pack or fun packs and a level pack, or having only singular packs.
- This makes it have the most packs out of any franchise in Year 2 (so far).
- In a list of leaked franchises from September 2015, the initials AT were argued to be either Adventure Time or the A-Team. Both of these franchises were introduced in Year 2.
- The show initially started out as a pilot short in Nickelodeon (owned by Viacom) in the cartoon anthology show Random! Cartoons in 2007, although it was created a year prior, only for it to be passed by the network twice before being picked up by Cartoon Network who enjoyed the short's atypical humor and released it in 2010.
- In The Simpsons season 28 premiere episode, there's a couch gag which is a reenactment of the Adventure Time intro and theme song, with Bart as Finn and Homer as Jake.
- Along with Scooby-Doo, Portal 2 and Jurassic World, they're one of the few franchises that had it's entire main cast come back to reprise their respective roles.
- Like DC Comics, The LEGO Movie, Teen Titans Go! and The Powerpuff Girls, the gateway has elements of the main characters.