Batman Unchained was the planned sequel to Batman & Robin. The script was written by Mark Protosevich and Joel Schumacher was signed to direct it. It was cancelled after the negative reception of Batman & Robin.
Protosevich's script had the Scarecrow as the main villain. The Joker would return as a hallucination in Batman's mind caused by the Scarecrow's fear toxin. Harley Quinn appeared as a supporting character, written as the Joker's daughter trying to get revenge on Batman for the Joker's death.
- George Clooney as Bruce Wayne/Batman
- Chris O'Donnell as Dick Grayson/Robin
- An unnanounced actor as the Scarecrow
- Jack Nicholson as The Joker (would return in Batman's mind as a result of the Scarecrow's fear toxins)
- An unnanounced actor as Harley Quinn
- Danny DeVito as Oswald Cobblepot/The Penguin
- Michelle Pfeiffer as Selina Kyle/Catwoman
- Tommy Lee Jones as Harvey Dent/Two-Face
- Jim Carrey as Edward Nygma/The Riddler
During the filming of Batman & Robin, Warner Bros. was impressed with the dailies. This prompted them to immediately hire Joel Schumacher to return as director for a sequel, but writer Akiva Goldsman, who worked on Batman Forever and Batman & Robin with Schumacher, turned down the chance to write the script. In late 1996, Warner Bros. and Schumacher hired Mark Protosevich to write the script for a fifth Batman film. A projected mid-1999 release date was announced. Titled Batman Unchained , Protosevich's script had the Scarecrow as the main villain with Schumacher wanting Nicolas Cage in the role. The Joker would return as a hallucination in Batman's mind caused by the Scarecrow's fear toxin. Harley Quinn appeared as a supporting character, written as the Joker's daughter trying to get revenge on Batman for the Joker's death. George Clooney and Chris O'Donnell were set to reprise the roles of Batman and Robin, respectively. However, when Batman & Robin received negative reviews and failed to outgross any of its predecessors, Warner Bros. was unsure of their plans for Batman Triumphant and George Clooney vowed never to wear the cape and cowl again. The studio decided it was best to consider a live-action Batman Beyond film and an adaptation of Frank Miller's Batman: Year One. Warner Bros. would then greenlight whichever idea suited them the most. Schumacher felt he "owe[d] the Batman culture a real Batman movie. I would go back to the basics and make a dark portrayal of the Dark Knight." He approached Warner Bros. of doing Batman: Year One in mid-1998.