Whether it's Iron Man fiddling with his arc reactor or Star-Lord getting hosed down, you can almost always count on the hero of any given Marvel movie to lose his shirt — it's practically a trope.

At this point —17 films and nine years into the Marvel Cinematic Universe — the "shirtless superhero" scene is up there with Stan Lee cameos, post-credits scenes, and 30something blond men named Chris in terms of reliable franchise staples.

Such serious commitment on Marvel's part, then, would seem to warrant some serious analysis on our part. And we do mean "serious." This isn't just an excuse for bald-faced objectification — goodness, no.

We've revisited all the MCU movies to date, focusing on humanoid heroes who usually wear shirts, and taking note of the moments in which they stop wearing shirts. Our totally, for-sure scientific system takes into account four major criteria:

Relevance to plot: How important is this scene to the story?

Relevance to character: Does the scene reinforce or reveal anything specific about the character?

OMG factor: How blatant the objectification is. (We see you, Marvel.)

Bonus: This is where we give and take points at will.

Where points were tied, we gave priority to the scene with the higher OMG factor. That's the real point of most of these scenes, after all.

For the purposes of this study, we ignored villains (e.g., Whiplash in Iron Man 2 and Ronan in Guardians of the Galaxy) and constantly shirtless non-humans (e.g., Drax in Guardians of the Galaxy, the big green Hulk). Women in bras, like Pepper Potts in Iron Man 3, were also excluded because female objectification is a whole other can of worms.

Also left out of this conversation are Iron Man 2 and Captain America: Civil War, neither of which has a shirtless scene – though both films do plenty to show off how buff their heroes' arms are.

Without delay, then, here's our deep dive into the MCU's most enduring – and most hilarious – trope.

1. Captain America: The First Avenger

Steve Rogers emerges from the super-soldier procedure looking much taller and much, much buffer.

Relevance to plot: 10/10. Captain America: The First Avenger is an origin story, so Skinny Steve's transformation into Swole Steve is literally the point of this entire movie.

Relevance to character: 6/10. It's a major moment in Steve's arc, but the scene focuses more on everyone else's reactions to his new body than does on his own. (He just says he feels "taller.")

OMG factor: 10/10. Chris Evans' perfect body would be impressive in any context, but this scene really makes a point of showing him off. There's a dramatic unveiling, followed by amazed reactions from every other character in the room. OMG, indeed.

Bonus: +3 for Peggy instinctively reaching out to feel his chest.

Total: 29 points.

2. Captain America: The Winter Soldier

Following a battle with Captain America, the Winter Soldier is back with Hydra getting his arm repaired – and, once they realize he recognized Steve Rogers, re-frying his mind.

Relevance to plot: 10/10. Bucky is the broken heart at the core of this film, and this is a pivotal moment in his storyline. It's when we learn exactly what Bucky's going through, and how much he knows or doesn't know.

Relevance to character: 8/10. Bucky's bare, muscled torso signals strength and power – but also vulnerability, surrounded as he is by scary-looking machines and scarier-looking people. He's a damaged man at the mercy of his handlers.

OMG factor: 3/10. The character stays shirtless for quite a while, and he flexes and heaves through the pain. You can't not notice that the man is built. But the scene is more interested in emotional nakedness than it is physical nakedness.

Bonus: +2 for that gnarly-looking metal arm.

Total: 23 points.

3. Avengers: Age of Ultron (Bruce Banner)

👀 Image: Giphy

During the team's stay at Hawkeye's, Bruce Banner exits the shower and has a conversation with Black Widow about their doomed romance.

Relevance to plot: 7/10. Bruce and Natasha's romance is a significant subplot in Age of Ultron, and this exchange helps establish some of the motives behind what happens next.

Relevance to character: 5/10. It's an intimate moment between lovers, and it calls back to a similar scene in The Incredible Hulk (where Bruce was played by Edward Norton).

OMG factor: 8/10. Bruce Banner actually goes topless pretty frequently, because his clothes get shredded every time he Hulks out. It's less common for him to go topless when he's just in regular old Banner mode. And the film makes sure you notice that he looks damn good.

Bonus: +2 because Ruffalo's Banner is only lightly muscled instead of super-swole. Among the MCU superheroes, that's what passes for body diversity.

Total: 22 points.

4. Iron Man

A shirtless Tony Stark calls Pepper into his lab to help swap out his arc reactor for a newer model.

Relevance to plot: 10/10. Not only does this scene further the Tony / Pepper romantic subplot, it becomes extremely relevant later on when Tony's new arc reactor is taken from him, forcing him to put the older model back in.

Relevance to character: 9/10. Whereas most of Marvel's shirtless scenes are about power and beauty, this one signifies vulnerability: he's unguarded with Pepper in a way that he is with no one else.

OMG factor: 1/10. It's nothing we haven't already seen – Tony has been in open shirts (to display his chest) and tank tops (to show off his arms) plenty of times throughout the movie by now.

Bonus: +1 for the arc reactor, because if nothing else, that makes Tony's shirtless scenes unique among all his brethren.

Total: 21 points.

5. Thor

Thor discovers low-rise Levis. Image: Giphy

After leaving the hospital, Thor changes into jeans and a t-shirt while Jane and Darcy look on.

Relevance to plot: 7/10. The scene ties into Thor's acclimation to Midgard and Jane's attraction to Thor, and it also sets up a Donald Blake Easter egg that pays off later on.

Relevance to character: 2/10. There's a nice moment when Thor examines his pants because he's not used to wearing jeans. It's a tiny detail, but a nice reminder that this character is not of this world.

OMG factor: 9/10. Thor puts its title character in extremely low-slung jeans, and then has the camera linger on him. Sometimes, he walks by a mirror so that we see two beefy Asgardian torsos at once. And as if all that weren't enough, the reactions by Jane (flustered) and Darcy (appreciative) really drive the point home.

Bonus: +1 for Erik's reaction to Darcy's reaction.

Total: 19 points.

6. Guardians of the Galaxy

Star-Lord is captured by Nova Corps and sent to prison, where he's stripped down and hosed down with orange liquid.

Relevance to plot: 3/10. It's relevant that Star-Lord's in prison. It's less relevant that he gets naked and wet while there.

Relevance to character: 1/10. The only information being conveyed here is "Chris Pratt is ripped now."

OMG factor: 10/10. If the point is to show us how good Chris Pratt looks today, well, mission accomplished. He's naked except for his boxer-briefs, and the film stays on this scene long enough to make sure we've drunk it all in.

Bonus: +4 for being totally unnecessary but extremely memorable.

Total: 18 points.

7. Spider-Man: Homecoming

Spider-Man sneaks back into his room, only to find his friend Ned waiting for him. He quickly changes into street clothes before Aunt May can catch him.

Relevance to plot: 9/10. Ned's discovery of Peter's secret is hugely important to everything that follows, as is Aunt May's ignorance of same.

Relevance to character: 5/10. It would seem to make sense that Peter is in spectacularly good shape, but beyond that, we don't learn anything new about the character by seeing him with his shirt off.

OMG factor: 4/10. Peter stays in his boxers for long enough that another character (Aunt May) comments on it, but the scene isn't really shot like a beefcake moment, perhaps because the character is so young.

Bonus: -2 for making everyone over 25 feel weird about noticing how hot this teenaged character is. +2 for giving everyone under 25 an age-appropriate hero to swoon over.

Total: 18 points.

8. Thor: The Dark World

This entire sequence is exactly as pointless as it looks. Image: Giphy

Thor washes up after a battle and before a party to celebrate his victory in said battle.

Relevance to plot: 1/10. This scene has very little to do with anything.

Relevance to character: 2/10. ... But it does show us that Thor's feeling a little introspective these days, I guess.

OMG factor: 8/10. It's Chris Hemsworth strutting around shirtless for seemingly no other reason than to show us Chris Hemsworth strutting around shirtless. In other words, the point of this scene is to give us something to ogle, and ogle we will.

Bonus: +4 for the shameless gratuitousness of it all.

Total: 15 points.

9. Thor: Ragnarok (Thor)

Chris Hemsworth takes part in a time-honored tradition: the shirtless superhero scene. Image: Marvel Studios

A group of women are tending to an unconscious Thor after his battle with the Hulk. He comes to and then begins getting dressed while speaking with the Hulk.

Relevance to plot: 7/10. This scene gets Thor in the room with Hulk, which is crucial to everything that follows.

Relevance to character: 2/10. There’s no real reason Thor needs to have his top off for this sequence.

OMG factor: 5/10. Another Thor movie, another shirtless scene that mostly exists to remind us that Chris Hemsworth is really, really, ridiculously good-looking.

Bonus: +1 for consistency – three films in, the Thor franchise remains as committed as ever to taking off Chris Hemsworth's clothes.

Total: 15 points.

10. The Avengers

Bruce Banner wakes up naked in a demolished warehouse, having crashed into it while in his Hulk form.

Relevance to plot: 5/10. It's canon that Bruce rips through his clothes when he Hulks out, so it makes sense that he's naked after the helicarrier fight.

Relevance to character: 6/10. Bruce's reaction to waking up naked in a pile of rubble tells us quite a bit about his relationship with the Hulk. He fears hurting others while in Hulk form, and of course he feels awkward showing up places naked – but it's also clear he's somewhat used to this whole process by now.

OMG factor: 2/10. Bruce's nakedness is presented matter-of-factly, and there's no one around who appreciates it. In other words, we're not really invited to ogle, though you still can if you want.

Bonus: +1 for the totally unfazed dude who finds him and throws him a pair of pants.

Total: 14 points.

11. Thor: Ragnarok (Bruce Banner)

Sadly, we don't have a photo of a bare-chested Bruce Banner. Hulk will have to do for now. Image: Marvel Studios

The Hulk transforms back into his human form, leaving us with a confused and mostly naked Bruce Banner. (Eventually, he puts on some clothes that used to belong to Tony Stark.)

Relevance to plot: 7/10. The character's entire arc here has to do with the split between Bruce Banner and the Hulk, and this scene reveals some essential details about what’s happened already and what might happen next.

Relevance to character: 4/10. Again, Bruce being naked a bunch is just part of the deal.

OMG factor: 2/10. Although Bruce remains bare-chested for a while, the sequence doesn’t stop long enough to let us admire him.

Bonus: None.

Total: 13 points.

12. The Incredible Hulk

The Incredible Hulk is a little unusual in that the character is shirtless on and off throughout the movie. Ratings below are averages of all the scenes.

Relevance to plot: 9/10. A certain amount of shirtlessness is built into the character, since his whole thing is that he grows enormous, thus bursting out of all his clothes. The Hulk is always bare-chested (he does keep his pants on, because these movies need a PG-13 rating), which means Bruce Banner is always bare-chested after transitioning back.

Relevance to character: 5/10. The Hulk spends a lot of time ruining his clothes, looking for new clothes, and getting clothed and unclothed.

OMG factor: 2/10. Edward Norton is in fine shape and all, but the real OMG moment in The Incredible Hulk is his CG transformation, which is another beast entirely. (Pun intended.)

Bonus: -3 because while there are a lot of shirtless scenes, none of them really make an impression. (Could you describe one from memory?)

Total: 13 points.

13. Guardians of the Galaxy Vol. 2 (Yondu)

Poor guy. Image: Giphy

The first time we see Yondu in Vol. 2, he's in what appears to be a brothel, buttoning his pants while he stares out the window at the other Ravagers having fun.

Relevance to plot: 2/10. This is just scene-setting. The actual plot-relevant stuff happens after he gets dressed and heads outside.

Relevance to character: 9/10. Before Yondu says a single word, his facial expression and body language tells us volumes about his state of mind. He looks troubled, depressed, lonely – and lonelier still once the robot behind him flips a switch on her head to turn herself off.

OMG factor: 1/10. Sure, it's a chance for Vol. 2 to remind you that Michael Rooker is in fine shape – but the slump of his shoulders provokes pity, not admiration.

Bonus: +1 for letting an older (by superhero-movie standards) man have his day in the sun.

Total: 13 points.

14. Avengers: Age of Ultron (Thor)

Troubled by his Scarlet Witch-induced vision, Thor immerses himself in a magical pool to help him understand what he saw.

Relevance to plot: 5/10. This is a big stop on Thor's vision quest ... but Thor's vision quest is, itself, only barely relevant to the rest of the movie. While Thor's hallucinations do give him some insight into the birth of Vision, their primary purpose seems to be giving the character something to do until Thor: Ragnarok.

Relevance to character: 2/10. That, and reminding us that, yes, this character is still in great shape.

OMG factor: 5/10. Age of Ultron knows exactly what it's doing by getting Chris Hemsworth soaking wet.

Bonus: None.

Total: 12 points.

15. Guardians of the Galaxy Vol. 2 (Star-Lord)

Chris Pratt: still all muscle-y! Image: Giphy

Back on the ship after their mission for the Sovereign, Star-Lord puts on a clean(ish) shirt as Gamora adjusts Nebula's shackles.

Relevance to plot: 3/10. The change of clothes isn't relevant in and of itself, but it leads into Star-Lord's conversations with Gamora (about Ayesha) and Drax (about Gamora), which are.

Relevance to character: 3/10. Of course Star-Lord is the kind of guy who picks up a shirt from the floor and sniffs it to see if it's still clean enough to wear.

OMG factor: 3/10. Chris Pratt's super-buff torso is no longer a surprise, and Vol. 2 tosses the scene in casually. It's there if you want to see it, but Vol. 2 doesn't go out of its way to present it to you like its predecessor did.

Bonus: None.

Total: 9 points.

16. Ant-Man

Paul Rudd has washboard abs now. Image: Giphy

Scott Lang tends to the wounds he got from training with Hope, and Hope gets a glimpse of his shirtless form.

Relevance to plot: 2/10. The wounds are minor and don't really factor into the rest of the movie.

Relevance to character: 2/10. Scott Lang doesn't exactly seem like the gym-rat type, so presumably the muscles are there to show us how hard he's been working with Hope and Hank.

OMG factor: 3/10. As with Chris Pratt in Guardians of the Galaxy, the objective here seems to be to show us that comedic actors can lift weights, too. But whereas Pratt's shirtless scene in that film was played straight, Ant-Man makes a half-joke out of Paul Rudd's. The result is more awkward than enticing.

Bonus: +1 because Hope's into it.

Total: 8 points.

17. Doctor Strange

Strange gives himself a makeover. Image: Giphy

Stephen Strange gives himself a more clean-cut makeover as he begins his training under the Ancient One.

Relevance to plot: 4/10. It's part of a montage showing that Strange is getting his life back on track after his post-accident spiral of despair, so ... sure.

Relevance to character: 1/10. Strange's bare chest adds nothing to our understanding of Strange. It just confirms that Benedict Cumberbatch worked out before this movie.

OMG factor: 2/10. ... Which would maybe be more exciting if Benedict Cumberbatch didn't always look like this. Or if there were any indication at all that Strange didn't always look like this.

Bonus: None.

Total: 7 points.

18. Iron Man 3

Robert Downey Jr. is probably even more relieved than Tony Stark is to get that thing off his chest. Image: Giphy

Tony Stark gets shirtless twice in Iron Man 3: briefly near the beginning of the movie after he spends the night with Maya, and for longer near the end of the movie when he undergoes surgery.

Relevance to plot: 7/10. The first scene establishes his relationship with Maya, an important supporting character; the second gets rid of Tony's arc reactor.

Relevance to character: 2/10. While the scenes matter to the plot, they don't really reinforce or expand our knowledge of Tony as a character.

OMG factor: 1/10. Iron Man 3 isn't interested in wowing viewers with a look at Tony's body. He's just shirtless in them because it makes more sense for him to have his shirt off in those situations than to have his shirt on.

Bonus: -5 because neither scene really even registers as a "shirtless scene," honestly.

Total: 5 points.

19. Avengers: Age of Ultron (Quicksilver)

Quicksilver, we barely knew ye. Image: Giphy

As Quicksilver suits up for the Battle of Sokovia, we get a blink-and-you'll-miss-it peek at his bare chest.

Relevance to plot: 2/10. Quicksilver is almost a non-entity in Avengers: Age of Ultron.

Relevance to character: 2/10. Hey, at least he gets to show off his muscles before he bites the dust.

OMG factor: 1/10. ... But it's only for, like, a second.

Bonus: -2 because no one even remembers who Quicksilver is, let alone that we saw his abs.

Total: 4 points.