Batman Unchained was the planned sequel to Batman & Robin being written by Mark Protosevich under the direction of Joel Schumacher. It was cancelled after the negative reception of Batman & Robin. Some themes and imagery from this script were later used in Batman Begins.
- George Clooney as Bruce Wayne/Batman
- Chris O’Donnell as Dick Grayson/Robin
- Alicia Silverstone as Batgirl/Barbara Wilson
- Michael Gough as Alfred Pennyworth
- Nicolas Cage as Dr. Jonathan Crane/The Scarecrow (role offered)
- Courtney Love as Harley Quinn (actress never hired)
- Pat Hingle as Commissioner Gordon (expected)
- Jack Nicholson, Danny DeVito, Michelle Pfeiffer, Tommy Lee Jones and Jim Carrey as The Joker, The Penguin, Catwoman, Two-Face and The Riddler respectively (they would return in Batman's mind as a result of the Scarecrow's fear toxins)
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 fifth film, 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 and it would bring back the franchise in a more serious and darker direction, unlike the previous two films.
The script dealt with Batman learning to conquer fear and to confront the demons of his past. The Joker would return as a hallucination in Batman's mind caused by the Scarecrow's fear toxin, along with The Penguin, Catwoman, Two-Face and The Riddler, all together to judge the hero on trial. Harley Quinn appeared as a toymaker, written as the Joker's daughter trying to get revenge on Batman for the Joker's death. Crane discovers Batman's identity and forms an alliance with Harley to lead him to madness and lock him in Arkham Asylum.
In the script, Robin abandons Batman for disagreements, but he returns during the final battle to help his mentor. After defeating his enemies and his demons, Bruce makes a trip to Bali and enters a cave full of bats, with them flying around him, as a proof for having conquered his fears.
Schumacher offered the part of the Scarecrow to Nicolas Cage while filming Face/Off and Courtney Love was proposed for the role of Harley.
However, when Batman & Robin received negative reviews and failed to outgross any of its predecessors, the idea was to bring Tim Drake in the Bat picture but Warner Bros. was unsure of their plans for Batman Unchained and George Clooney vowed never to wear the cape and cowl again. Director of the previous two films Joel Schumacher stated in a documentary that he turned down the chance to return stating that he lost his "passion" for Batman in film and didn't want to turn the passion into just a job.
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.
- The 2015 video game Batman: Arkham Knight draws some inspiration from the unused script to Batman Unchained, as the game features Scarecrow as the main villain and the Joker appearing in several hallucination scenes.