The 10th Victim is a 1965 Italian international co-production science fiction film directed by Elio Petri and starring Marcello Mastroianni and Ursula Andress, and featuring Elsa Martinelli in a supporting role. The picture is based on Robert Sheckley's 1953 short story "Seventh Victim". It depicts a government-endorsed, televised Big Hunt, featuring contestants from around the world acting as "hunters" and "victims"; when Marcello Poletti and Caroline Meredith, the game's two top assassins, are pitted against each other, they find that love is the most dangerous game of all.
Sheckley later published a novelization of the film in 1966, and two sequels (Victim Prime and Hunter/Victim) in 1987 and 1988, respectively. In the United States, the film was theatrically released by Joseph E. Levine's Embassy Pictures.
The movie is an international cult classic whose wild action and sexy style has influenced a generation of movies, from The Running Man to the Austin Powers series. It was also the first movie to features the reality TV death game theme, which was later used in other works such as Battle Royale, Series 7: The Contenders, and The Hunger Games.
(Summary from Wikipedia)