Iron Lung (the upcoming Markiplier horror movie) is rated R in the US because of its violent and disturbing content, not just “because it’s scary.” The official reasons are language, bloody images, and some gore.

Quick Scoop: Why Is Iron Lung Rated R?

In the United States, the Motion Picture Association has given Iron Lung an R rating “for language, bloody images, and some gore.” That means viewers under 17 need an accompanying adult to see it in theaters.

Core Reasons Behind the R Rating

  • Bloody images : The story centers on a submarine traversing an ocean of blood on a desolate moon, so graphic blood and disturbing visuals are baked into the premise.
  • Some gore : While it is not described as the most extreme splatter movie ever, the rating notes “some gore,” meaning injuries and violent moments are shown with noticeable detail.
  • Language : The film is also flagged for strong language, which on its own can push a movie into R territory when combined with intense horror elements.

How Other Places Rate It

  • In the UK, the British Board of Film Classification rated Iron Lung “15” for strong language, graphic imagery, and threat, blocking under‑15s from seeing it in cinemas.
  • Fan discussions note that in Australia it’s rated MA15+, while the US uses R, highlighting that different countries use different age labels for similar levels of content.

What Kind of Horror To Expect

The original indie game takes place in a cramped, failing submarine inside a literal ocean of blood, leaning into psychological dread and claustrophobia. The movie adaptation keeps that world, with Markiplier having even joked about aiming for record‑breaking amounts of blood in a horror film. Put simply, the combination of intense atmosphere, heavy blood imagery, and explicit language is what locks Iron Lung into an R rating instead of a milder one.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.