'Smallville' stars Tom Welling, Kristin Kreuk and Michael Rosenbaum discuss the show's legacy on its 20th anniversary

Twenty years ago, Smallville made audiences believe that a Superman-less Superman series could fly on the small screen. Premiering on the WB on Oct. 16, 2001, the show starred Tom Welling as the Teen of Steel, Clark Kent, as he tried to balance his Kryptonian heritage with his terrestrial existence.

But unlike past Super-stars — from George Reeves and Gerard Christopher to Christopher Reeve and Brandon Routh — Welling never got to change out of his civilian skivvies and into Superman's vintage red-and-blue ensemble. That's because Smallville creators Alfred Gough and Miles Millar instituted a "no tights, no flights" rule for their Last Son of Krypton that the show stuck to for its 10-season run.

"The whole idea was the show was about Clark Kent as he took that leap to be Superman," Welling tells Yahoo Entertainment in a 20th anniversary Smallville chat. The discussion reunited him with his former co-stars — and off-camera pals — Kristin Kreuk and Michael Rosenbaum, who played Clark's love interest, Lana Lang, and future nemesis, Lex Luthor, respectively. "We wanted to know he was out there, but we couldn't go with him. I'm very proud of what we did, and I'm really happy that we didn't go that extra mile."

Adds Rosenbaum: "It's called Smallville — if you involve Superman, then it just takes you out of Smallville." (Watch our virtual reunion above.)

Viewers certainly didn't have any complaints about Clark not suiting up as Superman until the final scene of the series finale. Along with Buffy the Vampire Slayer and Dawson's Creek, Smallville became one of the WB's defining teen shows, and its loyal audience followed along when it made the jump to the CW in 2006. For that crowd, Welling was Superman, even if he didn't have the "S" shield on his chest.

And Warner Bros. clearly recognized how Welling and Smallville had reignited the Superman brand. In the early 2000s, the studio was still struggling with how to bring Superman back to the big screen for the first time since Reeve hung up the cape following 1987's Superman IV: The Quest for Peace. Various projects — including Tim Burton's Superman Lives, J.J. Abrams's Superman: Flyby and George Miller's Justice League: Mortal — were developed and abandoned as the feature film franchise languished. Even Reeve saw Welling as his heir: The beloved actor guest starred on two episodes of Smallville prior to his death in 2004.

Asked whether Warner Bros. ever approached him about being their big-screen Superman, Welling confirms that some high-level conversations were had.

"It's a tricky question," he says. "Yes, I met with some people [at Warner Bros.]. But they were never like, 'Do you want to do it?' It was just like, 'Let's talk about this.' I know the numbers of what Smallville cost versus what a movie costs and to shut down Smallville for two years for me to go do a Superman movie was never gonna happen." Eventually, Bryan Singer's Superman Returns flew into theaters in 2006 with Brandon Routh in the title role, but that divisive movie failed to launch an ongoing series.

Meanwhile, Smallville continued to soar, especially as the creators moved away from the "monster of the week" installments that defined the show's first season in favor of serialized, character-centric storylines. That change in creative direction benefitted Kreuk in particular. Early on, Lana was primarily defined by her relationships to the male characters on the show — including Clark, Lex and her Season 1 boyfriend, Whitney (Eric Johnson). But the character evolved along with the show, with Lana gaining her own agency and, eventually, her own powers.

Kreuk says that she didn't personally lobby for Lana's transformation. "I wish that I had had the confidence at that point in my life to articulate what I wanted," she says now. "But I think they came to that kind of realization on their own as time went by. There's only so much you can do with the character if her only role is to facilitate stories with the other male characters on the show. If you can't find something that motivates and drives that person on their own, it all crumbles. And as I became more comfortable as an actor, I think there was more for them to play with as well."

While Clark pined for Lana, viewers at home rooted for another romance. Smallville fans saw sparks flying between Rosenbaum's Lex and Welling's Clark from their first meeting in the pilot, where the Teen of Steel saves young Luthor from a watery grave. "That was a terrifying moment for me," Rosenbaum says of his experience filming that scene. "They put me in a water tank twelve feet down in a car with weights on me. I was so claustrophobic... I'd swim up to the surface. I would just sit there [thinking], it's my first show, and I'm blowing it."

Rosebaum credits Welling with helping him through the scene, cementing a bond between the two actors that endures to this day. That sequence also launched the Smallville power couple known as Clex — the internet-friendly name for the widely 'shipped love story between Clark and Lex. The weekly Smallville recaps on the now-defunct website, Television Without Pity, even made room for a "Gayest Look of the Episode" award.

For his part, Welling says that his alter ego wasn't aware of the heat that Lex was throwing off. But Rosenbaum tells a different story. "I think we were sort of aware [of that]," he allows. "Our wardrobe guy would just say, 'Oh, they love you guys.' And I was like, 'Really?' There's just those moments where we're looking at each other and we just give that look. Let people fantasize and have whatever thoughts they have. I think that makes for good TV."

"There were a lot of longing looks between characters that would not exist in real life," Welling allows. "And that's time for the aduience to fill in their own story. I's not like Lana and Clark ever started at each other for any amount of time." Adds Kreuk: "I think we spent the majority of those years just staring at each other!"

While Welling remained with the series throughout its decade-long run, Kreuk and Rosenbaum bid farewell to Smallville after the seventh season. (Both actors did return for guest appearances in subsequent years.) "People think I quit the show and that's not true at all," Rosenbaum explains, adding that he stayed one year past his original six-season contract.

"I just felt like everything that needed to be told could have been told in seven years," he continues. "It was a tough character to play, too. I just felt like, 'I've done this. I've played this character long enough.'" Welling admits that the idea of continuing on without Lana and Lex was "confusing" at first, but he knew that the goodbye wouldn't be permanent. "It was more like, 'I'll see you later.'"

Flash-forward 20 years, and all three actors see each other regularly on the convention circuit. Welling and Kreuk have also been frequent guests on Rosenbaum's podcast, Inside of You with Michael Rosenbaum where they reminisce about their Smallville days and nights.

After the show left the airwaves in 2011, the CW built a new DC universe around shows like Arrow, The Flash and, most recently, Superman & Lois, starring Taylor Hoechlin as a grown-up Man of Steel who moves his family from Metropolis back to — where else? — Smallville. But the cast agrees that capturing the specific magic of their version of Superman's hometown would be tough to accomplish now. "There's a purity and an innocence to Smallville that just doesn't exist anymore," observes Kreuk. "Young people today don't live like that. In a world without social media and a constant connection to what is going on, you can't make that show."

— Video produced by Kat Vasquez and edited by Valerie Volpacchio

Watch our full Smallville reunion interview on YouTube

Smallville: The Complete Series arrives on Blu-ray on Oct. 19