WARNING: The following article contains spoilers for director James Wan's Aquaman, in theaters now.

Ever wonder how Aquaman is able to breathe underwater but also survive on land? Sure, the easy answer is that he's half-man, half-Atlantean, but that doesn't account for all the other characters being able to breathe air.

Director James Wan's Aquaman actually takes a moment to explain how it all works, and it's not what you may expect.

How the Whole Thing Works

While it involves genetics, it also seems to be a matter of class standing. Through the film's dialogue, it's explained only highborn Atlanteans are able to breathe both air and water. That means royalty and anyone who associates with them on a regular basis.

That's why Atlanna is able to flee to the surface and remain there for years, and why Mera can spend so much time on land. It's also why Orm can fight Aquaman on the surface at the film's climax. They're highborn, so they can survive wherever they go. While Vulko isn't exactly royalty, his position as a senior adviser likely comes down to his birth status.

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Meanwhile, lower-caste soldiers cannot breathe air on the surface. Therefore, they don powerful suits of armor that seemingly protect them from harm, enhance their abilities, and allow them to continue breathing water. They basically act as Atlantean spacesuits.

Just how sensitive are Atlanteans to an environment they can't properly breathe in? The movie shows us just that when Mera breaks the mask of an Atlantean assailant in Sicily. He begins to immediately suffocate. The Atlantean Murk only survives the destruction of his suit by sticking his head in a toilet. What happened to him afterward isn't clear.

A Problem That Needed a Solution

Aquaman

Rules were broken in order to make the movie as enjoyable as possible. For instance, the characters can speak underwater not based on any scientific principles, but rather for storytelling ease. Audiences wouldn't have the same experience if forced to read subtitles for much of the film, or to endure weird audio quality.

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In that same way, the film's explanation for why some Atlanteans are able to survive on land and others cannot makes perfect sense. It allows all the main characters in the movie to be clearly presented to the audience without the need for any kind of breathing apparatus. Fans are here to see Nicole Kidman, Jason Momoa, Amber Heard and Patrick Wilson, not their partially obscured heads.

We know that the class distinctions are made in order to perform a specific filmmaking duty, but that doesn't mean it doesn't enhance the quality of the feature as well. Putting the Atlantean soldiers in bulky suits with bioluminescent lighting effects makes them both intimidating and beautifully otherworldly. It's both convenient and necessary to make Aquaman a fully realized world.

Directed by James Wan, Aquaman stars Jason Momoa as Aquaman, Amber Heard as Mera, Patrick Wilson as Orm, Willem Dafoe as Nuidis Vulko, Yahya Abdul-Mateen II as Black Manta, Temuera Morrison as Thomas Curry, Dolph Lundgren as Nereus and Nicole Kidman as Queen Atlanna.