Prior to becoming an author, he had been a United States Marine, theatrical actor and producer. His theatrical experience may have contributed to his understanding of the energy, escapism and action that the public wanted in a novel. He once remarked: "I equate suspense and good theater in a very similar way. I think it's all suspense and what - happens - next. From that point of view, yes, I guess, I am theatrical." Some of Ludlum's novels have been made into films and mini - series, including The Osterman Weekend, The Holcroft Covenant, The Apocalypse Watch, The Bourne Identity, The Bourne Supremacy and The Bourne Ultimatum. A non - Ludlum book supposedly inspired by his unused notes, Covert One: The Hades Factor, has also been made into a mini - series. The Bourne movies, starring Matt Damon in the title role, have been commercially and critically successful (The Bourne Ultimatum won three Academy Awards in 2008), although the story lines depart significantly from the source material.

During the 1970s, Ludlum lived in Leonia, New Jersey, where he spent hours each day writing in his home.

Ludlum died in 2001 in Naples, Florida of a heart attack.

Ludlum's novels typically featured one heroic man, or a small group of crusading individuals, in a struggle against powerful adversaries whose intentions and motivations are evil, adversaries capable of using political and economic mechanisms in frightening ways. The world in his writings was one where global corporations, shadowy military forces, and government organizations all conspired to preserve (if it was good) or undermine (if it was evil) the status quo.

Ludlum's novels were often inspired by conspiracy theories, both historical and contemporary. He wrote that The Matarese Circle was inspired by rumors about the Trilateral Commission, and it was published only a few years after the commission was founded. His depictions of terrorism in books such as The Holcroft Covenant and The Matarese Circle reflected the theory that terrorists were only pawns of governments or private organizations that wished to use terror as a pretext for establishing authoritarian rule, not isolated bands of ideologically motivated extremists.

Ludlum used the same fixed titling pattern of The [Proper Noun] [Noun] for most of his books. Subsequent to his death, books written by other authors have carried the phrase Robert Ludlum^TM on their covers, thus asserting the name Robert Ludlum as a trademark. The actual author (not technically a ghost writer) is identified inside.