Jonathan Frakes, the actor who played William T. Riker in “Star Trek: The Next Generation,” is arguably one of the most important people in the “Star Trek” universe. Not only did he breathe life into the first officer of the Enterprise-D through his charm, charisma, and the Riker maneuver, but he would go on to direct two “Star Trek” feature films and a number of episodes across six Trek series to date. Frakes is so dedicated to “Star Trek,” he even offered to direct the long-awaited fourth Kelvin timeline movie in an email to J.J. Abrams.

With so much commitment to the franchise, it’s hard to imagine how different the world of “Star Trek” would be if Jonathan Frakes had not been cast as Riker — not to mention how different the character might have turned out. Maybe Worf might have ended up with Troi, or Riker would have finally gotten the promotion he deserved.

As recounted in “The Fifty-Year Mission: The Complete, Uncensored, and Unauthorized Oral History of Star Trek: The Next 25 Years From The Next Generation To J. J. Abrams,” three other actors who were seriously considered for the role included Michael O’Gorman, Billy Campbell, and “Star Trek” legend Jeffrey Combs. According to Adam Shrager’s book, “The Finest Crew in the Fleet: the Next Generation Cast On Screen and Off,” “Star Trek” fans came much closer to a world without Frakes than most realize. He endured seven auditions over a six-week period and only landed the part when the actor casting agents wanted for the role blew his final audition.

Had he been cast as Riker, who knows how long Michael O’Gorman’s list of credits might have been? As it stands, his IMDb entry is a fairly short one, with six credits spanning from 1987 to 1991, including an appearance in “Miami Vice” and an utterly silly role as a monster vying for the romantic affections of a widow with kids in the long-forgotten (and many would say forgettable) syndicated “Tales From the Darkside” byproduct, “Monsters.” A handsome actor with a bit of a Dennis Quaid thing going on, O’Gorman might have made a rather dashing Riker in another timeline.

O’Gorman’s name can be found on a Paramount memo to John Pike from Senior Vice President for Paramount Pictures Acquisitions & Co-Productions John Ferraro, who was involved with casting for the series. Dated April 13, 1987, the memo gives the short lists for main “TNG” cast roles, including Picard, Tasha, Data, Geordi, Beverly, Troi, and Wesley. Underneath Riker’s name — spelled “Ryker” on the memo — four names are listed: Michael O’Gorman, Gregg Marx (David Banning on “Days of Our Lives”), Jonathan Frakes, and Ben Murphy (Kid Curry on “Alias Smith and Jones”).

Although he didn’t ultimately land the role, O’Gorman seemed to have made quite an impact, as his name is explicitly mentioned in Ferraro’s notes beneath TheShockNews. The SVP writes, “For the role of ‘Ryker,’ Michael O’Gorman seems to be a favorite. He’s sort of an atypical choice for the role, however, a good one.”

Many fans consider Jeffrey Combs, who has appeared in nine roles across four “Trek” series to date, an absolute treasure of the franchise. Although he’s sometimes hard to recognize under the makeup, Combs brings a fairly recognizable, distinctive voice and has the ability to infuse his characters with vibrance and charisma. In fact, he’s responsible for two of the most appreciated aliens in the franchise — “Star Trek: Deep Space Nine” clone Weyoun and Captain Jonathan Archer’s (Scott Bakula) Andorian “Star Trek: Enterprise” bestie, Commander Shran.

But before all of that, Combs tried throwing his hat in for the role of Riker. Although “The Fifty-Year Mission” would call him a “front runner” for the role (p. 95), even he knew he wasn’t right when he auditioned for the part. On the DVD extras for “Deep Space Nine” Season 5, Combs called the prospect of himself as Riker “ridiculous,” admitting, “Even at the time, I thought, what am I doing?”

Fortunately, Combs didn’t let that deter him from future Trek auditions — even though he was never able to book anything on “The Next Generation.” After unsuccessfully trying for a few roles on “Deep Space Nine,” the actor’s persistence finally paid off when he landed a gig as a one-and-done alien in “Meridian,” an episode directed by Jonathan Frakes whom Combs knew socially. A month later, when his former theater connection René Auberjonois (Odo) was directing an episode, he brought up Combs, noting that it wouldn’t matter that he’d recently appeared on the series since the actor would be in prosthetic make-up again. One appearance led to another, ultimately landing Combs the role of his DS9 clone. “That was the beginning of Weyoun, which was a gift of a character. Just a wonderful, wonderful role,” Combs mused.

As Patrick Stewart recounted in his memoir “Making It So” (while lamenting his back-breakingly snug Season 1 uniform), Gene Roddenberry’s vision for the future was a thirsty one. And with the sexy soldier boy appeal that would land him “The Rocketeer” in 1991, Billy Campbell certainly had the beefcake Roddenberry was looking for in his “Next Generation” cast. That’s probably why he was the one person Roddenberry had hoped would play Riker. Up to that point, Campbell was best known for his role as bisexual “Dynasty” character Steven Carrington’s one true love.

But Campbell’s role as Riker, Enterprise-D’s one true lover boy, wasn’t meant to be. As “Next Generation” executive producer Rick Berman would recount in an interview with the Archive of American Television, “Campbell was initially cast in the role, but not everyone was willing to sign off on his performance — specifically, not John Pike, who was in charge of Paramount at the time.

“He didn’t feel he had a sense of command. He wouldn’t follow this guy into battle,” Berman recalled. For his part, the producer had disagreed, chalking Campbell’s performance up to a bad try out. “I think it was really more that he didn’t audition that well for the part,” he mused. Campbell would eventually get his chance to shine in the series, even if just for a moment, when he appeared in “The Outrageous Okona” as a dashing space cowboy one could easily imagine throwing back a few drinks with Mal Reynolds of “Firefly.”