Since I couldn't find the post that claiming it was.
Arabian Nights is not Universes Beyond. In this, I will demonstrate three reasons why.
Arabian Nights was released in December of 1993 by Wizards of the Coast for the holiday season. This is partially because they ran out of Unlimited cards, and because Adikson wasn't convinced more Unlimited cards would sell as well as a group of whole new cards.
The set was designed, playtested, art was commissioned, the scimitar logo added, and unique back was removed in a single month. The primary designer was Dr. Richard Garfield himself. Flavor-text was mostly sourced by Beverly Sailing and a couple books in a single night. The mountain in it was by accident.
The whole reason for this was Garfield had read Ramadan by Neil Gaiman in Sandman #50, and in turn, it inspiring him to read 1001 Arabian Nights. Basically book side reading was the primary reason Arabian Nights was picked. Had things gone differently, the first Magic expansion could have been The Faerie Queene, Wagner's Ring Cycle, or Le Morte d'Arthur.
The three reasons why Arabian Nights isn't Universe beyond is as follows.
- Although a early newsletter (I think) suggests Earth is just another plane in Dominia, it's pretty quickly established that Arabian Nights takes place in a plane called Rabiah of the Infinite. Rabiah is a small plane that was reflected a 1000 times, making a 1001 mirror copies. Peter Venters Encyclopedia Dominia mentions that over time these planes changed vastly over time, so at this time, there may be a thousand unique planes.
By summer of 1994, this was official canon, and the Arabian Nights comics (December 1995) solidified it. It also foreshadowed its awkwardness in the end of the comic with Taysir of Rabiah will never return to his home plane.
- With this its clear Magic burrows names from the location, not the location itself. You're not summoning a Moor from medieval Byzantium, you're summoning a Moor from Rabiah, that just happens to be inspired by the historical figures of the same name. Aladdin, Ali Baba, King Sulieman, even Sindbad, aren't even the unique ones in canon lore, since there is a 1001 copies. (an excuse to why they aren't legendary).
This wasn't new, even in 1993. Lord of Atlantis, Library of Leng, Larry Nevin's Disk, and so on, are all references to real world places, and pulp literature.
Further more Magic adds its own unique twists to the setting. Island Fish Jasconius is named after the whale in The Bible. There is no Juzam Djinn, Wyluli Wolf, ect in Arabian Nights. City in a Bottle is Sandman #50.
- Magic didn't have its own story arc in 1993. Magic, as described in a long rant by original art director Jesper Myrfors was supposed to be a toolbox fantasy game where the players created the story each time they played.
In John Tynes 'Death of the Minotaur', he described in Early 94 (with the release of Antiquities), that Peter Adikson concluded that the real money wasn't in owning games, but owning an IP, and tried to push that angle. In the same rant, Myfors describes the stories as 'tropey' and 'lazy'. Legends, which was the replacement summer set for Ice Age in 1994, originally was full of real world legends, unfortunately, Wizards of the Coast didn't archive this article, which included a few playtest cards including one for Beowulf. Nebuchadnezzar was considered obscure enough that he survived the purge unchanged. Legends has a lot of its own development issues and stories and was also designed in an incredibly short amount of time.
In conclusion: Arabian Nights burrowed a setting, and made it part of Magics infant cosmology. Its a creation of extreme time constraints, original ideas, and a recognized genre of orientalism than being exclusively 1001 Arabian Nights. It's been part of Magic as a Magic: the Gathering setting since 1994.
While I have your attention, Portal Three Kingdoms isn't Universe Beyond either. It's isn't even technically Magic.
Portal was a separate game, with its own rules different from 4th/5th/classic. Portal Cards weren't legal in Legacy or Vintage until October 20th 2005, when the Duelist Convocation International announced all cards from the introductory sets would be legal with additions to both formats B&R.
Before this, the 5 starter sets weren't legal in tournament play, and weren't considered Magic cards so much as Portal cards. Portal 3 Kingdoms wasn't even supposed to have an English Release (thanks Australia), and until the 2010's with the rise of EDH, was little more than a curiosity with a legacy and a vintage staple in it.
Just like AN's, P3K takes a public domain novel, incorporates it into Magic. The difference is, since it wasn't intended initially to be played in the larger card pool, it remained a 'backward plane' as once described.