The MCU would have been subtly changed if Mark Ruffalo had played the part of Bruce Banner in The Incredible Hulk. It's easy to forget that Mark Ruffalo was not the first actor to play the Hulk in the MCU; rather, that honor goes to Edward Norton, who appeared in The Incredible Hulk. There's a certain degree of irony in this, because director Louis Leterrier actually wanted Mark Ruffalo to play Bruce Banner, but he was overruled by Marvel. They were attracted to Norton's star power, while they considered Ruffalo a poor fit because they felt he only did "smart, intellectual movies" back then.

Marvel recast Norton, of course, and Marvel's What If...? episode 3 has gone one step further by placing Mark Ruffalo's Bruce Banner into the story of The Incredible Hulk. The clear implication is that everything in that film played out just the same, but Banner had a different face, voice, and mannerisms. It leads to an interesting moment in which Banner stands alongside forgotten Phase 1 character Betty Ross, the Hulk's classic love interest in the comics and from the movie. It's actually not the first time Marvel did this; a recent in-universe book called The Wakanda Files included an image with Ruffalo's Banner standing next to Liv Tyler's Betty Ross, but the change in the animated series is much more notable.

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But how would the MCU have played out had Leterrier had his way over a decade ago, casting Mark Ruffalo as Bruce Banner? There's no way to view these alternate timelines in the real world, but it's likely the MCU would have been subtly different.

The Incredible Hulk Would Have Been Changed Significantly

The Incredible Hulk

The Incredible Hulk was a troubled production, in part because of contrasting visions of just what it should look like in the first place. Norton pitched the Hulk as a two-part story like The Dark Knight, imagining it as what he called the modern "Promethean myth." He imagined the first part of the story as an origin, while the second would explore Bruce Banner as "the conscious dreamer, the guy who can handle the trip." An experienced scriptwriter in his own right, Norton actually reworked the script during production, although the extent of his rewrite remains controversial. Letterier seems to have generally been on board with Norton's vision, but Marvel disagreed; they were geared more towards making a commercially successful action movie. As he explained in an interview with The Huffington Post, "The first half of the movie is really mine and the second half is the studio's expected Hulk movie -- two giants kicking each other's ass."

This naturally means Ruffalo's The Incredible Hulk would have been completely different, simply because he wouldn't have conducted the rewrite. Ruffalo has openly admitted he was rather unconfident back when he joined Marvel, and assuming the same was true in this alternate timeline, there's no way he'd have been pushing his own interpretation of Bruce Banner. Some of Letterier's influence would have remained, but it's likely the first half of The Incredible Hulk would have been a little less dark, less foreboding, and the scenes written (or rewritten) by Norton would have either been cut or played out very differently. Meanwhile, Ruffalo's portrayal of Banner - which has markedly less physicality than Norton's, and more world-weariness than anger - would have affected pretty much every scene.

The Dynamic With Betty Ross Would Have Been Changed

Liv Tyler as Betty Ross from The Incredible Hulk

This would have had a particular effect on the dynamic between Bruce Banner and principal love interest Betty Ross, played by Liv Tyler. The Incredible Hulk has often felt like a second-tier MCU film, largely because Marvel pivoted away from it due to its poorer commercial performance, combined with their not owning the distribution rights for sequels. This has meant supporting characters have been neglected, with William Hurt's "Thunderbolt" Ross the only one to return. Had there been a strong dynamic between Ruffalo's Banner and Tyler's Betty Ross, though, Marvel may have been more keen to bring her back, too. Perhaps Tyler herself would have even voiced Betty in Marvel's What If...? episode 3, rather than being replaced by Stephanie Panisello.

Related: The MCU Has Only Used Marvel's Real Hulk Once

How Mark Ruffalo's Incredible Hulk Would Have Changed The MCU Going Forward

Thor versus the Hulk in Thor Ragnarok

It's impossible to say whether or not Ruffalo's Incredible Hulk would have been more successful than Norton's; while the script would have been very different, it probably wouldn't have been different enough to become a hit on the scale of Iron Man. Even if it had been more commercially successful, though, Marvel wouldn't have made more solo Hulk movies. The distribution rights to the Hulk are actually owned by Universal, not Marvel. That wasn't an issue back in 2008, because Marvel didn't have any distribution network of their own, but they gained access to Disney's when they were acquired by the House of Mouse in 2009. Disney prioritize Marvel properties where they own exclusive distribution rights, which are of more significant financial importance, while Universal don't seem particularly inclined to play ball with their rival studios.

All this means, as the story of the MCU continued, the impact of Ruffalo's debut in The Incredible Hulk would have become less with each film. Tyler may well have returned to the MCU a couple of times as Betty Ross, but it would only ever have been in cameos, perhaps with Bruce meeting with her just before he was recruited by Black Widow in The Avengers. Granted, if Bruce Banner had a preexisting love interest in the MCU, it's possible Joss Whedon wouldn't have come up with the unpopular Hulk-Black Widow romance storyline in Avengers: Age of Ultron. The biggest change, really, would have been a perceptual one; The Incredible Hulk would have felt like a "proper," integrated part of the MCU rather than an orphan, even if it still wouldn't be on Disney+ because of the aforementioned distribution rights. Like several episodes of Marvel's What If...?, this hypothetical timeline - in which Ruffalo played the Hulk right from the start - would end in a very similar place.

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