Although early reports from the set were mostly negative (even Marvel editorial was reportedly instructed by its superiors to ignore the upcoming film, on the basis that it would likely bomb), "X-Men" debuted in July 2000 to surprisingly strong reviews and an opening weekend that made it clear the film would be one of the most profitable of the year. The “X-Men” film franchise is the longest-running continuous superhero movie series in history, continuing in 2017 with the release of “Logan.”

RELATED: X-23: 15 Directions To Take The Character After The Logan Movie

With 17 years of releases, and over a decade of false starts, there’s no shortage of moments that fans could’ve witnessed in the movies. Here are 15 alternate castings, deleted scenes, and abandoned plot elements that narrowly missed the screen. Whether or not that’s a good thing is, of course, left to the reader’s discretion.

15 KEANU AS GAMBIT? DANZIG AS WOLVERINE?

Constantine (2005)

Numerous names are tossed around during the earliest production of a film, although the actual cast often doesn’t form until the final days. Even Hugh Jackman wasn’t cast as Wolverine in the first “X-Men” film until nearly a month into filming. Jackman was a last minute replacement for Dougray Scott, recently seen on “Fear the Walking Dead,” who had to drop out due to his commitment to the “Mission Impossible” sequel. Reportedly, Jackman was suggested for the role by his friend, Russell Crowe, who rejected the part earlier. During the days of a possible James Cameron-produced “X-Men” film in the early ‘90s, stout rocker Glenn Danzig was in talks for the role.

Other potential castings include Angela Bassett as Storm, Lucy Liu as Mystique, Edward Norton as Cyclops, Terrance Stamp as Magneto, Sarah Michelle Gellar as Rogue, and during the height of “Matrix” mania, Keanu Reeves as Gambit. Two alternate castings that came just as close as Dougray Scott are wrestler Kevin Nash as Sabretooth and James Caviezel as Cyclops. Both had to drop out due to scheduling conflicts. Tyler Mane, the eventual Sabretooth, was originally cast as Nash’s stunt double.

14 THE COSTUMES COULD'VE BEEN VERY DIFFERENT

Wolverine concept art for X-Men films

Early production art for the costumes have surfaced online, in addition to the images included with the 2000 DVD release. Initial designs were more colorful, with the X-Men and Brotherhood wearing outfits much closer to their traditional comic looks. Wolverine even had his trademark cowl in one early design! (Fans are still waiting for that one.) Magneto would’ve maintained his color scheme from the comics, and Mystique would’ve adopted a more snake-like appearance. Toad went through a variety of designs, some barely human, while Sabretooth at one point resembled a cowboy.

The surprise success of “The Matrix” in 1999 pushed the design sense of the film in a different direction during development. When early images of the costumes leaked online, fan response was swift and harsh. This is, according to lore, the genesis of Cyclops' crack about the X-Men wearing "yellow spandex" in the film. Bryan Singer was having fun with his critics -- some fans were amused, others are offended to this day.

13 SEVERAL NOTABLE CHARACTERS WERE DROPPED FROM EARLY DRAFTS

Beast Concept Art

Gambit and Beast were intended as additional members of the X-Men in the first film, but were dropped during subsequent drafts. If you’ve ever wondered why Jean Grey is a doctor in the films, it’s because her address to the Senate in the first film, and later examination of Wolverine, was originally going to be delivered by Hank McCoy.

The Brotherhood was initially going to have Blob and Pyro join Sabretooth and Mystique as members. Bryan Singer attempted to homage the excised characters with cameos during the first film, which inadvertently led to Pyro playing a larger role in the initial trilogy, going through a character arc that's unique to the films. Production art for Blob, who was in every early draft of the film throughout the '90s, was included as a hidden bonus on the initial DVD release. Gambit remained unrepresented in the first film, however. Singer eventually dropped plans for a teenage Gambit to appear during the students’ basketball scene.

12 THE DANGER ROOM COULDN'T CATCH A BREAK

Sentinel Concept Art

Storyboards that depict Wolverine discovering the Danger Room and fighting a fleet of flying robots are included on the 2000 DVD release of “X-Men.” A studio executive convinced Bryan Singer to cut the Danger Room scene, citing the potential cost, and the need to spend more time developing the characters. The Danger Room came much closer to appearing in “X2: X-Men United,” to the point that an actual set was built. The planned scenes were scrapped (the early designs featured a traveling control room for Xavier that hovered over the room like a propeller), but Singer did sneak in a door labeled “The Danger Room” into the background of one scene.

“X-Men: The Last Stand” does finally introduce the concept, but in the initial storyboards for the film, the Danger Room would’ve had a more explosive (and expensive) debut. The lone Sentinel head that makes a cameo was supposed to be an army of Sentinels, taking on the X-Men in a dystopic future. 10 years would pass before fans witnessed a true X-Men vs. Sentinel fight in the "Days of Future Past" film, even though the final designs bared little resemblance to the classic look director Brett Ratner originally considered.

11 HINTS OF PREVIOUS "X-MEN" DRAFTS STILL EXIST IN THE FILM

Wolverine and Rogue in X-Men movie

As late as 1999, Ed Solomon’s draft for “X-Men” had Wolverine as a more evolved warrior-philosopher with an interest in art. He sketches the face of a mysterious, beautiful woman from his past during his introduction in Solomon’s draft. Later revisions had Wolverine carrying a photo of a mystery woman instead. This was dropped from the finished film, but Hugh Jackman’s audition with Anna Paquin has her attempting to grab a photo of the mystery woman, and Wolverine snatching it out of her hand, during their truck ride in the film’s opening act.

The Jackman audition also has another line of dialogue that indicates a scene from an earlier draft nearly made it. Wolverine comments to Rogue that he’s already saved her life once, a reference to earlier plans for the trucker who brings Rogue into Canada to be revealed as a sexual predator. The actor who has the role of “Trucker” has his own history with the franchise -- George Buza was the voice of Beast on the 1990s “X-Men” animated series.

10 JEAN GREY LOSES CONTROL OF HER POWERS TWO MOVIES EARLY

Jean Grey in X-Men The Last Stand

Another “X-Men” moment that just narrowly missed inclusion was Jean Grey losing control of her powers when Senator Kelly presents a list of known mutants. She subconsciously uses her telekinetic powers and seizes the folder from Kelly’s hands, revealing herself to the public as a mutant. This is why, later in the finished film, Kelly refers to Jean as a mutant when discussing the issue with his aide, Henry Gyrich.  (Or the person he thinks is his aide, since we all know he's been replaced by Mystique.)

Kelly’s knowledge of Jean’s secret also explains why he decides to locate Jean Grey after Magneto mutates him. Apparently, this scene was scrapped while the movie was still being filmed, but there is another reference to it in the 2000 DVD’s deleted scenes. During a conversation between Xavier and Jean in the chambers of Cerebro, Xavier scolds her for losing control of her powers during her earlier testimony.

9 WOLVERINE NEARLY STOLE EVEN MORE OF THE SPOTLIGHT

Wolverine from X-Men (2000)

The basic elements of the initial “X-Men” film were in place by 1999, although one major plot revision was made shortly before filming. The X-Men assume for most of the film that Wolverine is the missing element that Magneto needs for his plan, and Rogue just happens to be a runaway caught in the mix. This was, in fact, the initial plan in most of the drafts, with Wolverine’s adamantium as the cherished plot device Magneto needs for his machine. As explained in the plot, Magneto requires the adamantium to work the way tungsten is used as a filament in a light bulb.

Initially, Wolverine bumps into Rogue (described as already 20 years old in Solomon’s draft) at a train station, rescuing her from lecherous frat boys, shortly before Magneto arrives to kidnap him. Wolverine saving Rogue from physical harm was a consistent theme in earlier drafts, but it was dropped at the last minute and replaced with the introduction of Wolverine as a cage fighter.

8 "X-MEN 1.5" WAS NEARLY WORTH THE DOUBLE-DIP

Jean Grey Storm and Cyclops from the X-Men movies

“X-Men” opens with a singular flashback to Magneto’s youth in a 1940s concentration camp. Earlier drafts describe a “trio of flashbacks” -- Magneto in Poland, Cyclops discovering his powers (and nearly killing a classmate in the bathroom) during Senior Prom, and Storm causing chaos with the weather in Africa. These scenes, in addition to a few other scrapped moments, are included in the initial "X-Men" paperback novel adaptation of the film's screenplay. Plans were made to film these additional scenes as bonuses for the “X-Men 1.5” DVD release, but they were eventually dropped. The high school bathroom set was actually built, and later repurposed for the Mystique seduction scene in “X2.”

Amazingly, an altered version of Cyclops’ scrapped moment made its way into 2016’s “X-Men: Apocalypse.” In this version, however, no one accuses Cyclops of smoking too much pot. Storm's origin moment remains unproduced, but who knows what the future could bring?

Sabretooth from the first X-Men movie

Earliest plans for “X2: X-Men United” has Sabretooth filling the role later given to Lady Deathstrike, before the graphic novel “God Loves, Man Kills” began to influence the script. The role of Stryker’s assistant mutated from a human named Annie, as seen in the graphic novel, to the more “kick-ass” Lady Deathstrike. It's very likely that Sabretooth was dropped when the producers realized that two villains with claws would be a tad redundant. Why go with a recycled villain from the previous movie when you can introduce someone new?  Sabretooth as a flunky for Stryker would, however, later appear in the film “X-Men Origins: Wolverine.”

Had Sabretooth been included, this would’ve left Toad as the only villain in the first film not to return for the sequel.  Toad, surprisingly, disappeared from the film series for over a decade, only making his return in 2016's "X-Men: Apocalypse."  Lady Deathstrike has yet to appear in any of the prequels/new timeline films, even though her appearance in “X2: X-Men United” was well-received.

6 STRYKER WAS ALMOST RESPONSIBLE FOR ANGEL BECOMING ARCHANGEL

Angel flying in X-Men The Last Stand

Early plans for “X2: X-Men United” had Angel as a student at Xavier’s school, kidnapped by Stryker’s men, and undergoing Weapon X-style experimentations that would create Archangel. This idea seemed to survive for a decent period during development -- the production designs created for Archangel appear as backgrounds in Stryker’s lab.  (They were also included as bonuses on the 2003 “X2: X-Men United” DVD release, if you want a closer look.)  Given that Bryan Singer had been playing with the idea of introducing Archangel for over a decade, it's surprising that he received such a lackluster debut in "X-Men: Apocalypse," although it is admirable that his origin was kept broadly consistent with the comics.

Another mutant we missed in “X2?” Once again, Gambit narrowly missed a cameo. Early plans had Gambit appearing during a montage of mutants assaulted during the Cerebro attack on mutants during the film’s climax.  Gambit would appear as a mystery figure, lifeless on the floor, surrounded by playing cards.

5 NOT QUITE BACK IN BLACK

Storm from X-Men 2000

While Brett Ratner’s approach to the third film “X-Men: The Last Stand” was, to be polite, controversial, he did exhibit more of a willingness than Bryan Singer to stick with the visuals inherited from the comics. Not only is Pyro suddenly blond in the third movie, but we also even see a glimpse of Mystique’s unique hairstyle that she uses in her Raven Darkholme persona during one scene. Ratner also managed to cast perfect physical reproductions of Moira MacTaggart and Madrox, the Multiple Man.

Ratner was apparently willing to appease fans who never warmed to the X-Men’s all-black, all-leather ensembles from the Singer movies. Plans were made for lighter, more colorful outfits, but the production didn’t have enough time to perfect the idea. However, you can see a quick glimpse of where the new designs could’ve gone when the X-Men discover…whatever-it-is that’s happened to Cyclops. Notice that Storm’s uniform is blue instead of black, and not as padded as the standard film costumes.

4 "X-MEN ORIGINS: WOLVERINE" COULD'VE BEEN LESS IRRITATING

X-Men Origins Wolverine

Earlier drafts of “X-Men Origins: Wolverine” by David Benioff and Skip Woods follow the same basic arc of the film, but are missing some of the more grating elements that offended fans. Deadpool doesn't appear at all, so the final fight scene is totally different. Earlier drafts have Wolverine facing an army of Sabretooth clones, none of them quite as evolved as the real thing.  It’s possible the writers intended this as an explanation for why the more comics-loyal Sabretooth in the film differs from the bestial Sabretooth seen in the first movie. (Magneto was employing one of Sabretooth’s clones!) The final film doesn’t bother to explain the discrepancy.

What’s also missing from the early drafts? No kiddie Emma Frost, mercifully. The off-model version of Bolt was initially going to be Beak from“New X-Men.” Those gratuitous Cyclops and Gambit appearances?  They’re nowhere to be found in the early drafts; it’s Barbarus of the Savage Land Mutates who runs into Wolverine in a New Orleans bar. Fans of classic “Wolverine” comics would also be pleased to know that Dr. Cornelius, his reluctant assistant Carol Hines, and the Dept. of Agriculture’s Pest Control Division all have a role in the plot.

3 BRYAN SINGER WOULD'VE CREATED A VERY DIFFERENT "X-MEN 3"

Sigourney Weaver headshot

Dan Harris, the co-writer of “X2” and early choice of Bryan Singer to pen the third film before he departed the project, has revealed some of the ideas from their plotting sessions. In Singer’s potential version, Jean Grey would’ve emerged from Alkali Lake as the Phoenix, declared her own war on mutant oppression (rescuing mutants from slave ships, which possibly could have introduced the concept of Genosha to the films), and found herself in pursuit by the X-Men, the Brotherhood and the Hellfire Club. Fans probably would’ve rejected the initial plans to have Sigourney Weaver star as the White Queen, the ruler of the Hellfire Club in this incarnation, but they would’ve received a more faithful plot than “The Last Stand” offered.

Harris' plans for “X3” give us another abandoned Danger Room moment. Cyclops, realizing that the team was woefully unprepared for threats like the Phoenix, would’ve created the Danger Room during the climax of the film.

2 JOSS WHEDON WOULD'VE CREATED A SOMEWHAT DIFFERENT "X-MEN"

X-Men movie poster

During the development of the 2000 film, Joss Whedon was one of several writers brought in to reimagine the cumbersome script. Shockingly, the full version of Whedon’s script doesn’t seem to have surfaced online, but we do know that “Entertainment Weekly” reported that it was rejected by the studio for its "quick-witted pop culture-referencing tone." Other info that’s been floated about the script has a potential romance between Wolverine and Storm, Magneto establishing Manhattan as a mutant sanctuary, another shot at introducing the Danger Room, and Jean Grey donning the mantle of Phoenix at the end.

Two lines of dialogue from the Whedon draft survive in “X-Men.” One is Storm’s infamous line about toads and lightning, which Whedon says was intended as an offhand remark. The other is Wolverine’s response to Cyclops, who wants him to prove that he isn’t Mystique in disguise. Wolverine uttering actual profanities? We were all stunned at the time...

1 "X-MEN" DEVELOPMENT HELL PRODUCED A PLETHORA OF ABANDONED CONCEPTS

Sentinel Head X-Men The Last Stand

Elements of "X-Men" go all the way back to Andrew Kevin Walker’s draft in 1994. Walker envisioned a full-scale mutant invasion of Manhattan, with Sentinels responding. A year later, Laeta Kalogridis penned a script that featured the '90s X-Men cartoon cast in a similar plot. Both of the Walker and Kalogridis scripts are larger than life and would’ve provided a challenge for any special effects house in the mid-1990s. The studio at the time was reportedly inspired by the success of "Power Rangers," which is likely why these attempts have more of a Saturday morning feel to them. A 1996 proposal by Michael Chabon is more cerebral, offering only a shadowy conspiracy as villains. In this draft, Jubilee’s parents are scientists working on the Weapon X project.

And those are just the scripts that led to 2000’s “X-Men.” Roy Thomas and Gerry Conway penned a 1984 script for Orion Pictures, before 1990's James Cameron project. Chris Claremont suggested Bob Hoskins for the role of Wolverine, and the fan press was calling for Arnold Schwarzenegger as Colossus. The project dissipated when Cameron pursued “Spider-Man” instead. (Which led to mess worthy of another list...)

Did the "X-Men" film series miss out on potentially classic moments or dodge a few bullets? Let us know in the comments!