Production

Justice League Unlimited features both episodic and serialized episodes, the first major overarching story arc involves the growing conflict between the League and a secret government agency known as Project Cadmus. This plot line builds upon events that occurred during the second season of Justice League (which in turn built upon events in Batman: The Animated Series, Superman: The Animated Series, Batman Beyond, Static Shock, and The Zeta Project), and would go on to affect the plotlines of most of its episodes. It was resolved in a four-part story at the end of the second season of Justice League Unlimited.

The third and final season story arc focuses on the new Secret Society (which is based on the Legion of Doom of the Challenge of the Superfriends season of Super Friends), a loose-knit organization formed to combat the increased superhero coordination of the first season. Towards the end of the series, certain characters became off-limits to the show, particularly characters associated with Batman and those who appeared in Batman: The Animated Series (aside from Batman himself) were restricted due to the unrelated animated series The Batman and Christopher Nolan's live-action The Dark Knight Trilogy, in order to avoid continuity confusion, thus leading to the popular term known as “Bat-embargo". Aquaman and related characters were unavailable due to the development of a pilot for a live-action series featuring the character as a young man (planned to be a spin-off of Smallville). To compensate for this, the last season focused their stories on previously overlooked DC Comics characters and mythos. These included characters like Deadman, Viking Prince, Warlord, and an unnamed modern equivalent of The Seven Soldiers of Victory.

The series, along with the entire DC animated universe, was originally planned to end after the second-season finale "Epilogue", which concluded the story of Batman Beyond and thus the entire DCAU chronologically. But a third season was greenlit by Cartoon Network. The third season started in 2005 with the episode "I Am Legion" (which was written before the announcement of a third season) and ended in 2006 with the episode "Destroyer". Stan Berkowitz, a member of the production team, left the show later for the TV series Friends and Heroes, and writer Matt Wayne was contracted to replace him. According to Matt Wayne, if the show had been renewed for a fourth season, he would have liked to write more episodes focusing on Superman and Wonder Woman.

DC Comics created an ongoing monthly comic book series based on the TV series, as part of its Johnny DC line of "all ages" comics, which did not have the same restrictions regarding character appearances.

Justice League Unlimited, like the second season of Justice League, is animated in widescreen. The show also features new theme music and intro (nominated for an Emmy).^[2] The two-part series finale was aired in the UK on February 8 and 18, 2006, and in the United States on May 6 and 13, 2006.

Protagonists

Supporting cast

Antagonists

Justice League Unlimited

DC Comics published a series of 46-issue numbered comics based on the television series, between 2004 and 2008.

• Justice League Unlimited: Jam-Packed Action! (2005-09-28): Adaptation of episodes 'Initiation' and 'For the Man Who Has Everything'.^[9]

Justice League Infinity

It is a sequel comic to Justice League Unlimited, written by James Tucker and J.M. DeMatteis with art by Ethen Beavers. 7 numbered issues were published by DC Comics between 2021 and 2022.