Well, then
The Walking Dead set of cards was originally released as a part of a timed-exclusive Secret Lair, and remained the only way to get them until Wilds Of Eldraine almost three years later, where they were reprinted with in-universe Magic characters in Magic settings
With the exception of basic lands (Plains, Island, Swamp, Mountain, Forest, and Wastes), your combined deck and sideboard may not contain more than four of any individual card, counted by its English card title equivalent
(He also explained many other Unfinity mechanics, but we're only concerned with Attractions here.) Here's his breakdown if you missed it: "Attractions represent all the rides, games, and shops you might visit while on the midway
With each additional expansion set added to the game, two more starter decks join the ranks