- Development Gag: Pax Americana #1 is basically Watchmen as originally intended—that is, with Charlton Comics characters instead of ersatzes. One exception is Thunderbolt, the model for Ozymandias, but not owned by DC. President Harley is something of an expy for both.
- Name's the Same:
- Bug was also the name of a different Spider-Man Captain Ersatz, a blue and red multi-armed superhero who was a member of The Maximums from Jeph Loebs run on Superman/Batman.
- Deadeye had previously been the name of an Evil Counterpart of Green Arrow from the planet Qward in the Anti-Matter universe, who appeared in Justice League International.
- Red Racer shares his name with the Red Ranger from Gekisou Sentai Carranger.
- Production Posse: The miniseries includes art from some of Morrison's previous collaborators, including Frank Quitely, Cameron Stewart, and Doug Mahnke.
- Saved from Development Hell: Notoriously in the works ever since the end of 52, scheduled for 2010, then 2012, then 2013, until finally being solicited in 2014.
- What Could Have Been
- Donna Troy was solicited to appear in The Just #1, and there were character sketches done by Ben Oliver released in earlier interviews. When the actual issue came out, Donna was nowhere to be found, and seemed to have been replaced by Artemis.
- The cover solicited for The Multiversity #2 featured Batman (Damian Wayne of Earth-16) and Blitzen (Flash of Earth-10) along with Aquawoman and Thunderer. The cover that was released instead had Red Racer, Atomic Knight Batman, and Machinehead of Earth-8, which made more sense since Red Racer and Atomic Knight Batman were more prominent in the main story than Damian and Blitzen. (It's also just as likely Blitzen was removed due to being a Nazi version of the Flash.)
- The hardcover collection contains sketches and mock covers done by Morrison, including an actual Doctor Manhattan cover done as an homage to Doctor Solar. There are also designs for a Major Max character who is either a counterpart to Captain Mar-Vell or Miracleman (Max's comic appears in Pax Americana).
- There was a time when Morrison promised to include the Young Justice universe as one of the Earths of the featured Multiverse. However, for whatever reason, the entire show and universe was relegated to a video game Offspring plays on Earth-16.
- Morrison's original 2009 proposal for the series, reprinted in The Multiversity Director's Cut #1, has a number of these:
- The series was originally intended to be eight issues: the two-issue framing story and the six spotlight issues for each Earth. There's no mention of the Guidebook.
- Society of Super-Heroes didn't have the Conquerors of the Counter-World part of its title; its internal title was "Doom from the Counter-world". Earth-20's Evil Counterpart was Earth-30 rather than Earth-40.
- The Just was set on Earth-7.
- Pax Americana was to begin with a student riot.
- The events of Thunderworld - specifically the Sivanas' creation of a new day - was what drew the Big-Bad Ensemble's attention.
- Ultra Comics was originally Ultraa the Unknown. Ultra himself was intended to be a Pinocchio-style character, a fiction who wanted to become real.
Trivia / The Multiversity