In “Rick and Morty” Season 6 Episode 1, a mishap with a portal gun teleports Morty (Justin Roiland) back to his home universe, which he and Rick left when it was overrun by a virus that mutated its inhabitants. Shortly after his return, Morty meets his father, Jerry (Chris Parnell). The two then share mutant meat cooked over a campfire in the post-apocalyptic shell of their ancient home. As they catch up, Morty suggests they play the board game Downbeat, which he mentions they never managed to finish.
Downbeat is basically a meta-joke from Season 4 Episode 5. In this episode, Beth (Sarah Chalke) walks into the Smith family dining room while Rick, Morty and Summer (Spencer Grammer) are in the process of completing a board game by the name play Dejected. As pointed out in a Reddit thread that has garnered more than 20,000 upvotes, a downbeat in screenwriting refers to the characters’ actions at the beginning of a scene. So the downbeat of this scene is literally the Smith family playing downbeat. It’s impossible to win, as Morty mentions, because it only serves as a disposable plot device.
“For me, a really balanced season has a couple of big guns throwing your guns at you,” producer Scott Marder said in an interview with GamesRadar. The downbeat callback in Season 6 Episode 1 isn’t, but it’s still an example of “Rick and Morty” making the most of its ever-expanding canon.