Star Trek's William Shatner Had One Condition For His The Big Bang Theory Cameo

One of the measures of a successful sitcom is the ability to attract star-power cameos from related media. You can judge the enduring popularity of "The Big Bang Theory" through the number of Star Trek cameos it boasted by the end of its 12-season run. The show included guest appearances from the likes of Brent Spiner, LeVar Burton, and George Takei — and, of course, Wil Wheaton (aka Professor Proton) had a recurring role as himself, too.

One coveted cameo that eluded the show for a long time, though, was the iconic, original "Star Trek" Captain James T. Kirk, i.e., William Shatner. 

By the time season 10 came out, Shatner had publicly clarified that despite the genre fit, he hadn't shown up on the show because he wasn't happy with the writing for a potential part. In a 2019 interview with the New York Post, the show's executive producer and showrunner, Steve Holland, clarified, "For one reason or another it didn't quite work out, whether it was scheduling or whatever." Holland added that going into the show's final season, Shatner remained high on their celebrity wish list. The holdout caved in the show's waning days, and Shatner agreed to make a prolonged and repeated guest appearance in season 12, episode 16, "The D&D Vortex." In the episode, the "Star Trek" icon plays a parody of himself as a member of Wil Wheaton's coveted celebrity D&D group. The factor that convinced Shatner to finally show up? Acting with Kaley Cuoco again.

Shatner wanted to do a scene with his acting buddy Kaley Cuoco

In the New York Post interview, showrunner Steve Holland clarified that it was the chance to act with Kaley Cuoco again that got Shatner fully on board with coming on the show. In Holland's own words, "I think what changed going into the final season is that he knows [series co-star] Kaley [Cuoco] from doing [Priceline] commercials together and they're friendly. When I got on the phone, one of the things he asked was, 'Will I get to play a scene with Kaley?'"

In a career littered with great roles outside of sci-fi, one of Shatner's most iconic roles has been as the Priceline Negotiator. He's been introduced to multiple generations as the man in search of the best deal — and in some of those commercials over the years, his character's daughter has gotten in on the hotel deal-brokering action. That next-gen price shopper was played by Cuoco, and Shatner clearly enjoyed acting alongside the "The Big Bang Theory" star. When he heard that his guest appearance on her show meant he would get another shot to act with Cuoco, it was an offer too good to refuse, and, well, the rest was history.