"xXx” introduced the world to superspy Xander Cage, played by Vin Diesel, but Eric Bana was initially eyed for the role. The actor reportedly turned down the part before choosing to star in 2003's "Hulk,” but Xander could have turned out much differently from what audiences saw in the final product.

Vin Diesel may have rubbed some co-stars — including Dwayne Johnson — the wrong way, but Asia Argento had only kind words about her "xXx" series co-star. Argento signed up for an "xXx" sequel, but never reprised the role of Yenna in the franchise, due to accusations she leveled against director Rob Cohen.

Vin Diesel’s production company was hit with a lawsuit after the news broke that "xXx: Return of Xander Cage" was in development. Diesel's former partner George Zakk alleged that they had an oral agreement where Zakk would receive a fee and producer credit for films he assisted in developing; he never did end up getting his credit.

Martin Csokas, who played Yorgi in "xXx," revealed that the film morphed into a different beast compared to the first script he received. The actor said that the script had themes of "the politics of anarchy," but "they just sort of went away," and asserted his opinion that the movie was "a lot more interesting to begin with".

Vin Diesel revealed that Universal wasn't keen on him making an "xXx" sequel for Paramount Pictures, saying, "These other studios can get very Mafia. They would just love to keep the golden goose at Universal." He also doesn't think Universal gives him much credit for being the George Lucas-style figure behind the "Fast and Furious" franchise.