In most cases, it's more like rated M for iMmature.

That makes sense though; the teen market is lucrative.

The idea behind them is that the person watching/playing is supposed to be mature enough to handle the content put in front of them. Are the games actually of mature nature that deal with mature themes and mature stories ect. Not so much in the most part.

Just thought of a good example: A game could be called Peniscoptor and be a bunch of penises flying around. It would be very immature, but would most likely have an M rating

Yeah, like how movies are rated R for restricted. What he said.

Ratings are there for parents who couldn't be bothered with looking further into their child's gaming practices than glancing at the front of a box, it's also there as a fallback for retailers who're tired of getting shit on by family/parent groups who fall in that same category.

Could people please get off their high horses with saying that "mature" games is really for teens or that they have the maturity level of a teenager. It's only a rating of the content itself and not a measurement of the maturity of an individual. Games with "mature" content/ mature themes are intended for teenagers and adults. 

Most M rated games are quite immature though.

Metroid Prime 2 and Majora's Mask 3D are some of the darkest games I've played and yet they're only rated 12+.

These games are more mature and subtle in their presentation than the majority of the M rated games.

ESRB and PEGI and other rating systems discuss appropriateness in relation to objectionable elements, not quality of thematic content. Just like a PG movie can be a mature work of art (Citizen Kane) due to density and maturity of theme, so can a T or even E rated game (Journey, Xenoblade, Metroid Prime, etc.). In fact, a game targeting intentionally to reach that M rating runs the risk of pandering, which is inherently immature. A Mature game can be rated M, but being rated M does not make it mature.

My eye's are rolling so hard they're about to pop out.

Ratings are meant to be nothing more than a way for parents to avoid having their children see beheadings or tits when buying games. It has nothing to do with its theme or quality.

https://www.reddit.com/r/WatchItForThePlot/