The following is a list of the movies that were considered to be in development by DC Comics, based upon different DC Comic Book Series and properties, but ended up not being produced in any way.
In August 2000, Warner Bros. announced that it was developing a live action film adaptation of the TV series Batman Beyond with Boaz Yakin attached to co-write and direct. The TV series' creators, Paul Dini and Alan Burnett, were hired to write a screenplay for the feature film, with author Neal Stephenson consulting the duo. By July 2001, a first draft was turned in to the studio, and the writers were waiting to see if a rewrite would be needed. The studio, also exploring other takes of Batman in development, eventually placed Batman Beyond on hold in August 2001. Robbie Amell (who portrayed Ronnie Raymond/Firestorm on the non-DCEU TV series The Flash) has talk about pitching his ideal Batman Beyond movie.
In May 2016, it was reported that Zack Stentz would write a Booster Gold movie with Greg Berlanti (executive producer of the non-DCEU TV series, Arrow, The Flash, Supergirl, and DC's Legends of Tomorrow producing the film, as well as currently being attached as director.
An interest fact, is that during the early development, the project was rumored to be titled Blue Beetle & Booster Gold, with Blue Beetle with a lead role along Booster Gold. This rumor could began when Berlanti tried to pick up a non-DCEU TV show of Blue Beetle (but the channel rejected the propose). It's currently unknown if Blue Beetle will start in the movie.
In March 2018, Greg Berlanti stated & confirmed that the Booster Gold film is still in development despite months of inactivity and lack of news reports.
Crisis on Infinite Earths
In 2013, it was rumored that Warner Bros. is considering an theatrical adaptation of the storyline Crisis on Infinite Earths. However, is currently unknown if this adaptation will be released or not.
It's also rumored that Warner Bros. will split the DC Extended Universe and the The CW's Arrowverse (the shared fictional universe of DC Comics which began with Arrow) for making the adaptation.
Green Arrow: Escape from Super Max
David S. Goyer and Justin Marks penned a script for a film starring Green Arrow originally called Super Max. On June 5, 2008, the film was retitled Green Arrow: Escape from Super Max. The reported storyline stated that Green Arrow (framed for a crime he didn't commit) must escape a high security prison filled with A, B and C list villains and rogue superheroes.
In an interview with MTV in 2008, Marks said:
"It's a very, very awesome prison. I majored in architecture in college, and design is how I actually started in. For 'Super Max,' designing that prison, it had to be the kind of thing that was a character in and of itself...We're in a world where instead of just trying to contain a guy who's really big, you're trying to contain a guy who can — in the case of Icicle — who can freeze things. What kind of a cell would a guy like that need in order to have his powers neutralized? So to escape from Super Max they have got to go through the most elaborate heist we've ever seen, involving superpowers. Because the prison itself kind of has superpowers!"Marks added that Black Canary would not be making an appearance in the film, and that it would include cameos from the Riddler, Lex Luthor and the Joker.
The second season finale episode of the non-DCEU TV series Arrow included a reference to Super Max, with the name being used for the underground prison where the villain Deathstroke is held.
Stephen Amell, who portrays the hero on The CW's Arrow, stated in July 2013 that he was interested in portraying the character in the upcoming Justice League feature. However, DC has consistently denied any continuity between the cinematic universe and the TV universe, which began with Arrow. It's unknown if the film will be a part of the DC Extended Universe.
In May 2011, it was reported that Warner Bros. Entertainment is in the process of hiring writers to pen a Hawkman film. The Thanagarians are also mentioned in the comic book prequel to Man of Steel by a member of the Kryptonian Council of Five as a "barbaric race". This confirms the Thanagarian's existence in the DC Extended Universe in which Man of Steel takes place.
Warner Bros. developed a Plastic Man movie in the early 1990s with Amblin Entertainment and Bryan Spicerdirecting. Filmmakers Lilly and Lana Wachowski wrote a Plastic Man screenplay in 1995, read and reported on by script reader and Yahoo! Movies columnist Greg Dean Schmitz in June 2003. The Wachowskis sought a Christmas 2009 release and were in talks with Keanu Reeves about starring.
In May 2007, it was revealed that Warner Bros. was in development on a Teen Titans film in which Robin was the only confirmed member. Akiva Goldsman and Mark Verheiden were writing it. The current status of the film remains unknown because on September 11, 2014; it was announced that Akiva Goldsman is now developing a Teen Titans TV series called Titans. Heroic Hollywood's El Mayimbe was a guest on the October 13, 2015 episode of Collider Heroes and he mentioned that Warner Bros. is developing both a Teen Titans movie with Cyborg among others and an all female group of heroes.
The Dark Knight Returns
At the 2008 San Diego Comic Con, film director Zack Snyder expressed his love for The Dark Knight Returns in a response to a question about the maturity of comic book adaptations. The Batman film franchise producer Michael Uslan expressed interest in a possible adaptation.
Despite this, Zack Snyder stated that Batman v Superman: Dawn of Justice was visually inspired by The Dark Knight Returns, and it featured an original premise.
The Swamp Thing
In April 2010, Joel Silver announced plans to produce a reboot of the Swamp Thing film franchise from a story written by Akiva Goldsman (the writer of Batman Forever and Batman & Robin). In April 2010, Vincenzo Natali was confirmed to direct, but on May 12, 2010, Natali decided to delay the film to pursue other projects.
In 2005, screenwriter Hadley Davis (Ice Princess) announced that she had written an action-comedy featuring a teenaged version of Zatanna. Nothing further was ever heard about this project, and it is presumed to have been abandoned.