Trivia: Booker is a nod to "Good Guys Wear Black" in which Chuck Norris portrayed a character named John T. Booker. In both films Norris plays a retired military operative in a rescue mission to help his old comrades.
Trivia: When Booker is telling The Expendables about a snake that bit him and then a few days later it died, is from the infamous Chuck Norris Facts. Booker is played by Chuck Norris.
Trivia: Despite being R-rated, the film is largely devoid of profanity. This is reportedly because Chuck Norris refused to appear in the film unless all the profanity was removed from the script.
Trivia: When stuck in the mine, Gunner says he's going to blow the wall and starts digging around. Barney says he could be onto something, as Gunner has a degree in chemical engineering. Dolph Lundgren, who plays Gunner, has a degree in chemistry from Washington State University, a degree in chemical engineering from the Royal Institute of Technology in Stockholm, and a Master's Degree in Chemical Engineering from the University of Sydney.
Trivia: In the German version of the film, Arnold Schwarzenegger and Sylvester Stallone are voiced by the same actor.
Trivia: When Booker is in the helicopter towards the end of the movie, Barney Ross says to him, "I thought you were the Lone Wolf." This is a reference to the 1983 film "Lone Wolf McQuade", which also starred Chuck Norris.
Answer: "We keep it light" refers to their mood. They joke around and tease each other and have fun. "Till we go dark" is when they get serious for killing. "We go pitch black." Meaning as dark and brutal killing machines as possible.
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