Every shooter sold at American retail carries a rating letter and a row of content descriptors beneath it. That combination is produced by a submission process the publisher starts long before the game is finished.
The publisher submits and the board assigns
The Entertainment Software Rating Board is an industry self-regulatory body rather than a government agency. Publishers submit their own games and pay for the review.
Submission includes a detailed questionnaire covering violence, language, sexual content and gambling-like systems, plus footage of the most extreme content in the game.
Raters who are not industry employees review that material and assign a rating category with descriptors. Withholding relevant content from the submission can invalidate the rating afterward.
Descriptors carry the specifics
The letter alone conveys an age band. The descriptors underneath tell a parent what produced it, distinguishing stylized combat from blood and gore or from strong language.
Two shooters can both be rated Mature for very different reasons, and the descriptor line is where that difference appears. Retail buyers and parents read it more closely than the industry expects.
Interactive elements are noted separately, covering in-game purchases, user interaction and location sharing. Those notices exist because the experience changes once other players are involved.
Ratings shape what gets built
An Adults Only rating is commercially close to fatal in the United States, because major retailers decline to stock those titles and console platform holders generally will not certify them.
Development teams therefore design toward the Mature boundary rather than testing it, adjusting depictions of injury during production rather than after a rating comes back.
The line is not written down precisely, so studios rely on precedent, on prior submissions and, on larger projects, on informal early consultation about where content sits.
Marketing is rated separately from the game
Trailers, storefront images and television spots are reviewed against advertising guidelines that limit where mature content can be shown and to which audiences it can be targeted.
A shooter's most violent sequence may therefore be absent from every advertisement even though it is central to the game, which is a rating rule rather than a creative choice.
Failing those guidelines can force campaign material to be pulled and recut, so publishers route marketing assets through the same compliance path as the game itself.
Digital storefronts changed the pressure
Console and mobile storefronts require ratings, but PC digital distribution largely does not, which is why small shooters sometimes ship unrated to a US audience.
That gap matters less for enforcement than for parental controls, which key off rating data to filter what a household account is allowed to install.
An unrated game simply falls outside those systems, which is why storefronts have gradually pushed self-assessment tools onto developers who would previously have skipped the step.