Marvel and director Jon Favreau cast Downey as Iron Man over studio resistance rooted in his past, with the actor reportedly having to screen-test and accept conditions few stars would.
By the mid-2000s Downey was sober but still viewed as a gamble. When Jon Favreau pushed to cast him as Tony Stark, the studio was resistant given his history, and Downey had to audition and prove his reliability for a role that would ordinarily go to a bankable, low-risk star.
The bet paid off spectacularly: Iron Man (2008) launched the Marvel Cinematic Universe and made Downey the highest-paid actor in the world. The episode is often cited as one of the great casting decisions in Hollywood history, and as vindication of his recovery.
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