Since its release in 2008, Jon Favreau's Iron Man has had an incalculable impact on modern movies. Not only did it kick off the ongoing Marvel Cinematic Universe and guide it on its way to becoming highest-grossing film franchise of all time, but its influence can be felt in blockbuster filmmaking in general, with many franchises opting to construct their own shared and interconnected universes. It also reminded industry people and audiences alike of Robert Downey Jr.'s talents, and set RDJ on the path to becoming one of the most popular actors around, making him an undisputed A-Lister in the process.

As with any adaptation of a pre-existing property, certain changes have to be made when it comes time to translate the source material to the big screen. Most of these have been either benign or beneficial to the Iron Man cinematic canon, but there have still been some decisions made that irked fans of the comics or simply didn't work for a multitude of reasons. We collected some of the biggest head-scratching decisions by Shellhead's filmmakers and present you with the 15 Worst Changes From The Comic Book To The Movies.

15. Stark and Banner create Ultron

Marvel's Ultron

Rogue A.I. robot and recurring Avengers headache Ultron finally made his big screen debut in 2015's Avengers: Age of Ultron. In the movie, the James Spader-voiced Ultron is the product of Tony Stark's ill-advised meddling with artificial intelligence in his quest to build a “suit of armor around the world”. The result is the super-villainous robot who comes to the conclusion that humanity is too dangerous to survive on its own and needs to wiped out completely.

In the comics, Ultron is created by genius scientist Hank Pym, aka Ant-Man/Giant Man/Wasp/Yellowjacket (he has a lot of aliases). As the Ant-Man movie was released several months after Age of Ultron, and featured an older Pym with the younger Scott Lang in the suit, the chronology would have made little sense. However, Stark and Banner aren't the Marvel Universe's only smart guys, and with the likes of Reed Richards and Dr. Doom locked away in Fox's vaults, the Cinematic Universe is missing some of its biggest brains. The thing that made Ultron so dangerous was the fact his brainwaves were based on Hank's own. Pym had a troubled past and a dark side to him, and Ultron was the manifestation of all of his deeply personal fears. Had the cards fallen differently, we may have been treated to the spectacle of a sneering James Spader going toe-to-toe with Michael Douglas.

14. Not enough suit diversity

A selection of Tony Stark's Iron Man suits on the poster for Iron Man 3

This is admittedly a minor point, but Tony Stark's fantastic armors haven't been given much attention in his movie appearances. Apart from the significantly bigger Hulkbuster armor in Age of Ultron and possibly the hulking prototype Mark I in the first movie, they all basically look the same. Fans of the comics had been wanting to see the Silver Centurion suit in action since the movies began. However, when it did finally make an appearance in Iron Man 3, it was simply in a fleeting cameo, and the suit was blown up at the end as part of the “Clean Slate” protocol.

In the comics, Stark is constantly making new and different versions of his suits with unique capabilities. We've seen some glimpses of more exotic suits like the Red Snapper, Bones, and the heavy-lifting Igor, but like the Silver Centurion, we never really got a chance to see what the armors could do, which is part of the fun of it all. A bit more variation wouldn't go amiss, especially now that Tony has destroyed nearly all of his armor collection. We won't rest until we see Stark's sentient metal Endo-Sym armor makes its big screen debut.

13. Iron Patriot isn't Norman Osborn

Norman Osborn as Iron Patriot with the Dark Avengers - Marvel Comics

With movie rights being what they were back when Iron Man 3 came out, the original backstory for Iron Patriot was never going to make it to the big screen. During the Secret Invasion event, Norman Osborn, aka Spider-Man's arch nemesis the Green Goblin, ends up being perceived as a hero, bravely fighting the Skrull invasion. Osborn's still rotten to the core, however, and he uses his media exposure to become a trusted and beloved champion of the people.

When the U.S. government shuts S.H.I.E.L.D. down, Osborn is given control of the Superhuman Registration Act and the country wide Avengers initiative. Osborn plays up to his media role and secretly assembles the Dark Avengers – a gang of supervillains (including the always awesome Venom) posing as familiar heroes. Osborn paints his Iron Man armor like Captain America's uniform and becomes a secret supervillain himself. Once the Dark Reign era was over, the suit was then piloted by James Rhodes, who made Iron Patriot the heroic symbol he was meant to be.

In Iron Man 3, Iron Patriot is just a respray and a rebranding of War Machine. This is fine, but it does skip some potentially juicy stories with Norman Osborn involved. Willem Dafoe or Chris Cooper would have both been fine choices for the role, but the MCU being what it is, we'll never see it happen.

12. No Rescue...yet

Pepper Potts discovers the Rescue suit in Invincible Iron Man #10

Of all the entries on this list, this is the most likely to still happen at some point. In the comic, Pepper Potts gets a custom Iron Man suit and becomes the superheroine Rescue. Pepper isn't in the same league as Tony and Rhodey, but she soon comes into her own as a hero and becomes a full-fledged and valued member of Tony's team.

We've already had hints of this in Iron Man 3, with Tony using the suit to protect her from his collapsing mansion (on top of her superheroics during the finale). However, actress Gwyneth Paltrow has gone on record as saying she's unclear about her future in the MCU. It seems probable she'll make an appearance in one of the forthcoming Avengers movies, but whether it'll be anything more than a quick cameo remains to be seen. Rescue shows a different side to Pepper and it could be interesting to watch her evolve from PA to CEO to superheroine. Plus, Marvel could always do with a few more kickass women in its ranks.

11. Rhodey doesn't become Iron Man

James Rhodes as Iron Man

One of the things you may not know about James “Rhodey” Rhodes is that he had a stint in Stark's armor and became the new Iron Man before he ever suited up as War Machine. In Iron Man #169, Tony gets incredibly drunk and takes supersuit for an ill-advised spin. He goes on a bender and ends up flying through some billboards in Times Square. After failing to stop the supervillain Magma, Stark returns home and collapses. Rhodey walks in and discovers what Stark's been up to. Rhodes finds out that Magma is still at large and has no choice but to suit up and try to stop him. After the incident, Stark refuses to put the suit back on and gifts it to his best pal. Rhodey's run as Iron Man lasted two years before Stark reclaimed the title. The distinctive War Machine armor came later on in the comics and is a gift to Rhodey after Tony Stark's “death”, serving as an olive branch between the two previously feuding men.

Don Cheadle's Rhodes does get some time in an Iron Man suit in the movies, but it's an earlier model and it serves as the basis for the War Machine armor made by Justin Hammer (who we'll get to in a bit). Whilst the cinematic approach is more streamlined, it does take away from the special significance of the War Machine armor somewhat.

10. Tony hasn't gone into space...yet

Iron Man Space Armor Guardians of the Galaxy

Okay, he's technically been into space in The Avengers. However, he didn't spend too long up there before suffering a terrifying fall thanks to his heroic self-sacrifice. In the more recent comics, Tony joined the Guardians of the Galaxy and built himself a shiny new space armor. With James Gunn categorically denying an Iron Man cameo in Guardians Vol. 2 on Facebook, we'll probably have to wait a long time before Tony sets off on any galactic adventures (if he ever does).

It's a shame, as Tony learns a lot from his time in space, and the inclusion of it into the MCU could shake up the formula and show a different side to Stark's personality. Comic book Tony joins the Guardians to gain a new outlook on life. It turned him into a fish-out-of-water, and made him the audience stand-in for when complicated space things had to be explained. For once, our hero was a small fish in a big pond. This could be an interesting direction to take the character, but for the moment, Tony seems like he'll stay on good ol' planet Earth.

9. Justin Hammer

Justin Hammer speaking at the senate hearing in Iron Man 2

Making his first appearance in Iron Man #120, Justin Hammer is a wealthy old British industrialist and head of Stark International's rival, Hammer Industries. When Stark takes his company out of the weapons production business, Hammer Industries became the market leader. Not content with this, Hammer sets out to destroy Stark's mascot Iron Man in a symbolic gesture. Hammer also has a secret business of taking in supervillains and equipping them with the latest dangerous technology for 50% of their total money earned. He's a cantankerous jerk through and through, and it makes him a compelling foil for Iron Man to deal with.

Iron Man 2's Hammer is a lot younger...and American. Whilst he's played with a lot of energy by the great Sam Rockwell, he's not given enough development to ever truly pose a threat to Stark. There are elements of his supervillain bankrolling, but Vanko (oh, don't worry, we'll get there) plays him for a fool and leaves him in the dust. Hammer's attempts to out-Stark Tony are fun, but his motivation and personality aren't well-sketched enough to make him a memorable villain.

8. Iron Monger/Obadiah Stane

Jeff Bridges as Obadiah Stane

Obadiah Stane is an interesting entry in Iron Man's rogues gallery. In the comics, Stane is a genius and master tactician who constantly plots to take over Stark Enterprises. He's a gifted manipulator who can identify people's weaknesses and use them to get ahead. At one point in the Iron Man series, Stane succeeds in locking Tony out of his own company, renames it Stane International, and basically wins so hard that Tony starts drinking again. Stane later finds some incomplete blueprints for an Iron Man suit. He has his top scientists work on it and soon becomes the Iron Monger, a hulking supervillain with the same basic abilities as Iron Man himself.

Movie Stane is slightly different. Jeff Bridges does a great job in the role, but the character is a little lacking. Stane isn't particularly well-fleshed out, and once his good guy act wears off and he reveals his true intentions, the movie loses steam and ends with an underwhelming thumpfest between the two men. Had Stane been given more personality or been shown to be a brilliant evil mind, we may have cared more about his motivations and perhaps even have saved the big showdown at the end from being a little unsatisfying.

7. The Extremis storyline

Iron Man's Extremis Armor

Back in 2005, an effort was made to reinvent Iron Man for the more modern era. The task fell to writer Warren Ellis, who basically took all of Iron Man's convoluted backstory and previous adventures and ignored them, rewriting Tony Stark's origin from the ground up. Stark originally was in the Vietnam War, but Extremis updated this to a more modern conflict. In the comic, Stark flashed back to his younger days making weapons inspections in Afghanistan. The truck he's near is attacked, and one of his own landmines explodes in his face, leaving him grievously injured. If you haven't read the comic and that still sounds familiar, it's because it's basically the opening of Iron Man 1 (minus the AC/DC).

However, Iron Man 3 owes the biggest debt to the Extremis storyline. It takes the central premise of the comic (a superpowered nano-virus thing), several of the character names (Maya Hanson and Aldrich Killian), but very little else. As Extremis is often voted as one of the best Iron Man stories thanks to its strong characterization and exciting plot, it seems a pity that it was chopped up in the movies. It's highly unlikely that we'll ever see a true adaptation.

6. No Mallen in Extremis

Mallen in Iron Man: Extremis

Mallen doesn't have the name recognition of the Mandarin, but he's an interesting one-story villain nonetheless. Mallen is a domestic terrorist that uses a stolen Extremis dose on himself, transforming into a rampaging super-powered villain. Tony tries to stop him, but suffers one of the biggest and nastiest beatdowns he's ever received. Stark almost dies from his injuries, and is injected with Extremis to save his life. After some rest and recuperation, the new and improved Tony makes a stunning comeback and finally takes the terrorist down. In an interesting twist, Tony is forced to kill Mallen when it becomes clear that he has no intention of stopping his one-man terror spree.

Mallen could have been an interesting addition to the MCU. His nondescript killing and brutality may not be particularly family-friendly, but he could have been a break from the parade of corrupt businessmen that have been the big bads in all of the solo Iron Man movies so far.

5. Stark's relationship with Pepper Potts

Iron Man 2 - Iron Man and Gwyneth Paltrow as Pepper Potts

Virginia “Pepper” Potts has been a regular fixture in the Iron Man comics since her debut in Tales of Suspense #45 way back in 1963. The pair like each other immediately, but after several miscommunications and missed opportunities, Pepper ends up dating Stark's bodyguard Happy Hogan instead. The Hogans had a rocky marriage and it eventually ends in divorce. Stark and Pepper do share a kiss, but agree to be platonic soon after.

In the movies, poor ol' Happy Hogan isn't a factor. After some partying in the first film, Stark only seems to have eyes for Ms. Potts, and the pair eventually get together. Making Tony a one-woman kinda man isn't necessarily a bad change, but it sands off some of the edges of the character. Tony has a weakness for women and booze (see: #4 on our list), and neither of these vices are explored with much depth. Comic book Stark doesn't really go for long monogamous relationships, and to make Tony just another paired off Avenger arguably makes him less distinctive as a character. In Captain America: Civil War , it does seem like the pair have split up, but we don't know much about the reasons behind it. Could this be the beginning of Tony slipping back into bad habits? Only Kevin Feige knows for sure, and he's not returning our calls.

4. Stark's alcoholism

The cover of Iron Man #128 featuring the famous Demon in a Bottle story

Tony Stark has battled with the bottle many times over the years in the comics. Stark has struggled to juggle his personal life as the CEO of a giant company and being an Avenger and often found solace in alcohol. This is one of the darker elements of Stark, one that has only been played lip-service in the movies and was done and dusted with in Iron Man 2. In the movie, Stark has issues with drink, but he mostly comes off as a hard partier rather than a full-on booze hound. Even when his antics result in a supersuit vs. supersuit showdown with Rhodey, things really don't get too dark.

The Demon in a Bottle story is one of the seminal Iron Man tales. It gave billionaire genius Tony Stark a relatable edge and eventually reaffirmed his motivations for being a hero. As Iron Man 2 riffed on it slightly, it seems that the chance to adapt the story has come and gone. Apparently, Iron Man 3 director/co-writer Shane Black wanted to use the story as the basis for his sequel, but Disney declined. Black alluded to Disney's family-friendly reputation being the reason behind the decision, so it's pretty safe to say Tony won't be battling the booze in the future.

3. Aldrich Killian

Guy Pearce as Aldrich Killian in Iron Man 3

People unfamiliar with the Iron Man comics may have wondered about the backstory of Guy Pearce's slick Stark-alike Aldrich Killian after watching Iron Man 3. Well, wonder no more -- there isn't one. Well, not really. In the comics, Aldrich Killian is a scientist who helps create Extremis, an unstable “virus” that can give superhuman abilities to the infected. He sells a stolen sample of the virus to a terrorist group. Consumed by guilt, he shoots himself at his desk, admitting to his crime in his suicide note. Cheery. The point is that Killian's story is over and done with in a paltry ten panels.

This makes Iron Man 3's take on the character an all-new creation. One which some fans didn't appreciate too much. Even if you like the villain, it can be said that Killian's portrayal is a little cartoonish, even by comic book standards. Much like Electro in The Amazing Spider-Man 2, they Batman Forevered their villain. Killian's arc has the same basic beats as Jim Carrey's Riddler origin back in 1995. He's a gawky nerd who admires our hero until a perceived betrayal, whereupon they both embark on elaborate schemes to punish their respective billionaire playboys. Considering Iron Man 3 had a clean slate, it's disappointing it chose to travel such a well-worn route.

2. Whiplash

Ivan Vanko walking down the racetrack in Iron Man 2

There have been numerous supervillains that have gone by the name "Whiplash" in Marvel Comics. The first was a man named Mark Scarlotti, a thug who worked for the Maggia crime syndicate. He has cybernetic whips and an eyebrow-raising bulletproof outfit. The second Whiplash was Leeann Forman, who, apart from having too many vowels in her name, was a mutant who used adamantium whips instead of Scarlotti's titanium ones. You'll notice that neither of these versions remotely resemble Mickey Rourke's take on the character in Iron Man 2.

For some reason, Iron Man 2 combined the Scarlotti Whiplash's general aesthetic with another supervillain, the Crimson Dynamo. Now, Whiplash was Ivan Vanko, scorned Russian scientist who blames Howard Stark (and consequently, Tony) for screwing his scientist father out of millions of dollars and leaving him to die cold and penniless. Rourke's take on the character is pretty divisive amongst fans, but most agree that the film doesn't give him enough screen time to flesh out the character. As such, he ends up as just another forgettable MCU villain (if not one of its worst). This is doubly a shame, as the Crimson Dynamo could have been a great villain for Stark to face-off against, and since his backstory has already been utilized, it seems unlikely he'll make an appearance in the future.

1. The Mandarin

Ben Kingsley in Iron Man 3

To say the changes to the Mandarin were controversial is to put it mildly. Even people with a passing knowledge of the Iron Man comic books would probably be aware that the Mandarin is Tony Stark's arch nemesis -- the Joker to his Batman. Mandarin is a powerful megalomaniac who uses ten magic rings he reverse-engineered from a crashed alien ship. He has an intellect to rival Stark's and is a skilled martial artist, making him a real force to be reckoned with. It has to be said that many of the character's early appearances were steeped in outdated Asian stereotypes, but more recent incarnations have refined the character.

Iron Man 3 pulled a bait and switch that many fans responded poorly to. The trailers and the first half of the movie portray Ben Kingsley's Mandarin as a terrifying techno-terrorist, hijacking TV signals to warn the West of its decadent ways and claim responsibility for recent attacks on American soil. As Tony digs deeper into the mystery, he discovers that “The Mandarin” is actually a junkie British actor named Trevor Slattery. The whole thing has been a set-up by Aldrich Killian – the "real" Mandarin. The twist is completely unexpected, but dramatically unsatisfying. After being teased with a newer, scarier take on the biggest Iron Man villain of them all, it's hard not to pine for what could have been. On a positive note, Marvel One-Shot All Hail the King sets up the possibility of a legit Mandarin we've yet to be introduced to, which could mean a future MCU appearance for ol' Mandy.

--

What other creative digressions from the source material have you not appreciated from the Iron Man films? Sound off in the comments.