The two actors are co-writing the script for The Last Duel alongside Nicole Holofcener, PEOPLE confirms. The film is based on the revenge novel by Eric Jager.
This is the first project Damon, 48, and Affleck, 46, are co-writing since their Oscar-winning film Good Will Hunting, which won for Best Original Screenplay and Best Supporting Actor for Robin Williams.
Jager’s story, which is called The Last Duel: A True Story of Trial by Combat in Medieval France, is a revenge story depicting two best friends, the knight Jean de Carrouges (Affleck) and the squire Jacques Le Gris (Damon).
Carrouges goes to war and returns to accuse Le Gris of raping his wife. When no one believes her, Carrouges asks the king of France for a chance to prove his wife was right. The two former friends end up in a duel to the death.
If Carrouges loses, his wife will be burned at the stake for her false accusation.
Damon has previously collaborated with Scott in 2015’s The Martian. Affleck and Damon are also starring in Kevin Smith’s Jay and Silent Bob, reprising their previous roles, Holden and Loki, from some of Smith’s films such as Chasing Amy and Dogma, respectively.
Deadline first reported the news.