The first Rambo movie, “First Blood”, was actually based on a somber novel by David Morrell about the difficulty veterans faced readjusting to life after war.
The Rambo character in the movie is being hunted by an unsympathetic police force and escapes into the wilderness, using the survival skills he honed in Vietnam to stay ahead of them.
The script called for Rambo to leap off a cliff into a tree in a moment of desperation. A young Sly Stallone, hot off his “Rocky” fame and eager to prove he meant business, decided he would do the stunt himself.
Without safety gear.
It took three tries before Stallone got a take he was satisfied with. What you see in the film is completely real. He leapt off a nearby cliff into a tree, cracking his ribs in the process. He received some light medical care and then continued filming for the rest of the day.
Stallone’s been known to take his stunt work very seriously. Even today the actor still insists on performing in his own fight scenes, despite the fact that he is pushing 70.