Smith plays both the older assassin, Henry Brogen, 50, and the clone, "Junior," 23, thanks to deaging technology.
"This story is not one that could have been told with cinema as we know it. However, thanks to incredible new digital technology, not only can we finally see both younger and older Will Smith embodied together on screen, but we can also experience the story in a deeply immersive way,” Lee said in a statement, according to MSN.com. “It is my great fortune to be able to experiment and test the limits of what new digital cinema has to offer us. No less so to be able to work with two Will Smiths – one beautifully sophisticated, the other exuberantly honest."
The Oscar-winning director added that rapper-turned-actor playing both roles was "magical."
The "emotional and physical challenges of making this film have been the most demanding of my career," Smith said in the same statement. "Ang is pushing the limits to give people an experience in the movie theater that you can't get anywhere else. This is not only an action film, but an exploration of what one's younger self can ultimately teach one's older self."
Gemini Man opens in theaters on October 11.