RE: Movie Ratings and the Law
From what I can tell, this is more complex than it seems.
The Motion Picture Association of America (MPAA) rating system is completely voluntary, just like the ESRB's rating system is. However, many places choose to enforce this on their own. Much like how stores have rules in place to not sell M games to kids, many theaters have rules in place to keep people from buying R rated movie tickets.
However, there are states like Tennessee that ban the sale of tickets rated R and above to minors.
(see https://law.justia.com/codes/tennessee/ ... 39-17-907/
The problem is, this doesn't apply to films that are listed as NR (Not rated) so if the studio chooses not to opt into the OPTIONAL MPAA rating system, they can get around it. Additionally, many of these laws only apply to the SALE of tickets.
If someone's 18-year-old brother wanted to buy a ticket and give it to their 12-year-old sister, they could.
However, some states have laws preventing people under the age of 21 from buying more than one ticket at a time to prevent this from happening with as about as much success and you can assume.