Rumors that the 42-year-old actor will appear in the film began to circulate earlier this year. The star confirmed the news on Friday when he appeared on Jimmy Kimmel to discuss his new film, Transcendence.
"I can do all sorts of things," Bettany said of Vision's powers. "But I'm not really allowed to talk about them."
"[Studio executives] pick and choose [from the comics]," the actor continued. "It's very exciting for me, but everything is a double-edged sword. I was playing Jarvis [in the Iron Man movies] for years and my job was to turn up at a recording studio for forty-five minutes, do all my stuff, and then they'd give me a huge bag of cash and then I got home."
"Now it turns out they found me out and want me to actually do something," he joked.
The character Vision is an android who possesses the ability to absorb solar energy and discharge the power as optic beams. He can also manipulate his density in order to become intangible, or to provide himself with superhuman strength.
The new movie will follow Vision and the Avengers as they face off against the villain Ultron (James Spader). The characters Quicksilver (Aaron Taylor-Johnson) and Scarlet Witch (Elizabeth Olsen) will make their first appearance in the Marvel film series alongside returning characters Iron Man (Robert Downey Jr.), Hulk (Mark Ruffalo), Captain America (Chris Evans), Black Widow (Scarlett Johansson), Hawkeye (Jeremy Renner) and Nick Fury (Samuel L. Jackson).
Avengers: Age of Ultron debuts in theaters on May 1, 2015. Paul Bettany will next appear in Transcendence with Johnny Depp on April 18.