FAQ

As of June, 2024, the most prominent actors still alive are;

Stuart Cooper - Roscoe Lever

Colin Maitland - Seth K. Sawyer

George Roubicek - Pvt. Arthur James Gardner

U.S. Army Major John Reisman (Lee Marvin) is "asked" by General Worden (Ernest Borgnine) to train a dozen hardcore military prisoners, some of them sentenced to death by hanging, so that they can be led on a dangerous mission, called "Project Amnesty", behind enemy lines. In return for their service, the prisoners will have their sentences commuted... if they survive.

The Dirty Dozen is also a 1965 novel by E.M. Nathanson, said to be inspired by the Filthy Thirteen, a real life Demolition Section of the U.S. Army whose job it was to demolish enemy targets behind the lines. The book was adapted for the movie by Nunnally Johnson and Lukas Heller. A sequel, The Dirty Dozen: Next Mission (1985), followed in 1985.

They are: (1) Tassos Bravos (Al Mancini), (2) Victor Franko (John Cassavetes), (3) Glenn Gilpin (Ben Carruthers), (4) Robert Jefferson (Jim Brown), (5) Pedro Jiminez (Trini López), (6) Roscoe Lever (Stuart Cooper), (7) Archer Maggott (Telly Savalas). (8) Vernon Pinkley (Donald Sutherland), (9) Samson Posey (Clint Walker), Seth Sawyer (Colin Maitland), (11) Milo Vladik (Tom Busby), and (12) Joseph Wladislaw (Charles Bronson).

To parachute into France, infiltrate a guarded French château in Rennes, Brittany, being used by high-ranking German officers as a rest house, kill as many Germans as possible, and destroy the communications tower in an effort to disrupt their chain of command before the Allied invasion on 6 June 1944.

It's evident in the movie that Colonel Breed (Robert Ryan) and Major Reisman greatly dislike each other, but no details about their backstory is provided. It's explained in the book that the mutual contempt between them began in Italy. Reisman, an OSS officer, was working undercover with local partisans in Italy and had observed Breed's arrogant and dismissive treatment of the paratroopers under his command. Reisman, dressed as an Italian peasant, had seen Breed order his men out of a small cafe in which some of the troopers had stopped to have a drink. Reisman broke character and called Breed out for the jerk he was in English, telling him that he ought to give his guys a break and let them drink because tomorrow some of them might be dead. The pompous Breed, embarrassed in front of his men, was furious and had Reisman arrested and held until his identity was confirmed.

Those were pencil detonators aka timing pencils, basically pens with blasting caps and short-duration timers, settable by turning. It's never made clear why he took them. It's possible a scene was cut that explained it.