The Oscar-winner plays the English folk hero in Sir Ridley Scott's adaption of the classic tale, which also stars Cate Blanchett as Maid Marion.
The blockbuster includes a series of high-action scenes, in which hundreds of extras play out fight sequences - and Crowe admits many of the actors suffered for their art on the movie battlefield.
He tells Britain's Sunday Mirror newspaper, "We had 15 people carried off a battlefield at one point. One guy got his eye poked out with a pike. Another guy broke an arm and a leg falling off a horse. The scale of it is enormous... In this film you had 130 horses doing a full-speed gallop charge into 600 guys on the ground. Every man on a horse did half-a-dozen fight moves before spinning around and coming back."
And Crowe reveals director Scott took some risks himself - the moviemaker was heavily involved with the action sequences, even plunging into the sea during a beach battle scene to make sure the shot was perfect.
He adds, "Ridley jumped into the waves and grabbed this 15-ton barge with both hands, bum, knee and all, and starts trying to push it out of the shot. When it was clear he was not going to win his lone battle against the barge he looked back at the beach and said, 'Well, what are you waiting for?' That's leadership."