Some games, such as Dungeons and Dragons, come with ratings/recommended ages before they can be played. Are those accurate? Beyond the ratings, are there any general guidelines I should follow when deciding whether to allow my children to participate in an RPG game, unsupervised?
There's a variety of dimensions to whether an activity is appropriate for children of a given age or not.
There's no inherent age limit for "roleplaying." Kids roleplay from a very young age via "cops-and-robbers" (though nowadays it's more likely ninjas vs Transformers or something). Group imaginative play as kids is RPGs without the pedantry of dice and rules. Frankly kids roleplay more than all adults put together. My daughter and her friends basically roleplay with Littlest Pet Shops for hours on end, just without dice or formal rules. So I don't believe there's any specific age limit for the pure act of roleplaying.
You should check out the content of a given RPG and see what ages you think it's appropriate for. Something like D&D may not be content appropriate for certain ages in some people's minds (violence, magic). There's other games with even lighter content (Toon, the cartoon RPG, might be the lightest). So there it depends on the game. The RPG industry is bizarrely conservative, however, so most RPGs don't go past what I would consider a Y7 show on TV (with some exceptions like oWoD, but even those are mostly PG). The current cartoon "Adventure Time" is basically D&D, they even use D&D terms in it. So many games are pretty kid friendly, unless you're of the "Harry Potter is evil" contingent, and even then there's other games that probably omit whatever you object to.
When Hasbro puts an age rating on D&D they're not likely doing it out of content concerns, as all the content in D&D is way less objectionable than an average episode of "Billy and Mandy" - they're probably doing it to indicate what age a kid likely can perform the activities required, like they have on all their board games. If you try to play Parcheesi with a 5 year old everyone will end up crying. Kids of age X probably can't do the math/read the books/understand the rules. Of course, there are games much simpler than D&D that even younger kids could play. I made up a basic minis game I played with my daughter when she was 6, "high roll wins" on a d6 is understandable down young. If your kid is comfortable reading chapter books, they'll do OK with less complex variants of D&D and other simple games. If they're still into picture books, you'll need something lighter and maybe customized to kids. If they're reading board books, don't bother. It's not just about the math - are they going to be disruptive; can they participate in a group doing something for a couple hours in general without flipping out? This varies by kid.
RPGs are a group activity. What do you mean by "unsupervised?" You mean gaming with their siblings at home with you around and just not participating in the game per se, which would be fine as long as they are not so young they'll be disruptive and generate a lot of intra-sibling screaming? Or do you mean dropping them off at the local gaming store to play "D&D or whatever" with the 15 (heck, and 25 and 35) year olds that hang out there while you go to Walmart? Are they going to play in a generally safe environment, and, if you're not picking them up/dropping them off, are you comfortable with their means of transportation to/from there?
RPGs are little different from any other group activity in this regard; there's a certain level of supervision and mix of kid ages and distance (sibling, relative, friend, schoolmate, stranger) any parent has already decided is appropriate for their kids whether the activity at hand is playing an RPG, playing Pokemon cards, playing soccer, going to the mall, or whatever. Different people are different here and times change - when I was a kid, at seven I and whatever kids were loose on our street would go disappear into the woods nearby and pursue our own shenanigans all day; today most kids are on lockdown and aren't let out of any adult's sight for more than 5 minutes until they're 13. Whatever your deal is there, you'd apply the same standard of supervision to a group of kids playing an RPG.
Don't think an RPG group is any safer than any other group - I wouldn't send my kid to go hang out with an arbitrary group of older people without myself or an adult I trust around. Use good judgment about any group your children hang out with.
It depends on what you mean by "unsupervised."
My son has run a monthly game for years - he's 14. Most of his players are about his age, but some are younger. Mostly, the youngest come attached to older siblings, but that's not always the case.
Those kids are playing unsupervised in that their parents are not at my house - they're out shopping and going to lunch in places you can't bring kids and running errands and generally being giddy at the prospect of 4 hours of free time.
But they're not unsupervised because at least one adult is at the house at all times.
So if by "unsupervised," you mean, "without an adult participating in the game," I think you can let them play as soon as they express the interest and have a GM and gaming environment you are comfortable with.
It's probably a matter of choice and dependent very much on the kids they're playing with and the game they're using.
For instance, the original D&D games had a 13+ recommendation, but with the proliferation of violent computer games, television programs, and whatnot it's become kind of silly in comparison so the age recommendations were mostly removed.
I'd highly recommend sitting in on a game or two. You'll get a good feel for what's going on and whether it's appropriate or not. I used to run a non-violent game with some Christian friends and when their parents heard about the game they stopped it without ever having seen what we were up to. I'm almost sure if they'd seen what we were actually up to they wouldn't have minded so much.
If I was in that position, I'd check the people they are gaming with. Are they of the same age? Are they from families you trust and approve of? If so, you probably don't need to worry too much. If, on the other hand, they want to game with 19 year old total strangers, I'd think twice (or random people on the internet).
The other thing I'd check is the system. Some games reward a lot of violence and killing. Others are more appropriate to younger ages. For instance, I know of a company which just put out a game geared towards younger children called "Story Realms". I'd say that game is appropriate to pretty much all ages. On the other hand, I probably wouldn't let young kids play Call of Cthulhu or something like that (horror RPG).
As for role-playing itself. I don't think it's inherently harmful. Most little kids play cops and robbers, building cities, house, and what not from a fairly early age.
I hope this helps in some way!
I ran a game shop for 3 years in Salt Lake City. I can tell you that we did not let anyone under the age of 13 play in our shop unsupervised by an Adult. With that said, there were exceptions that were made for kids who proved themselves trustworthy (as another poster already mentioned is possible).
For RPGs, I think the biggest portion of it is how mature the child is. I have seen children as young as 10, or even 8, do an OK job and have a good time. I know of at least one parent that runs a (simplified) D&D campaign with his 6 and 8 year old, but without all the nitty-gritty rules (very fast, very light).
I had a number of parents come in and ask me similar questions. Most of them were there for answers, as they had heard "bad things" about RPGs. I have seen some people go a little overboard with their roleplaying, but not many. (I can only recall one example, actually). If the child is over 12 or 13, I think that at that age they have begun to grasp reality vs. fantasy, and have begun to understand what is possible in the world (both through experience and learning). This varies from child to child however. At 10, I was playing RPGs with friends, and was able to turn off the "Fantasy world" pretty easily. My brother did not have so easy of a time until he was 12 or 13.
In short, it depends a lot on the child, and a lot on who they are playing with. If they are with friends who are of a similar age and maturity level, then they probably won't need "adult supervision" in the same way.
I am also reminded of something my father said to me, and this is something I have mentioned to more than one worried parent. He always said that he was happy I played roleplaying games, because he knew where I was, what I was doing, and that I wasn't doing drugs or illegal activities for fun. I would add in that RPGs tend to increase reading skills, they actually can improve communication skills, they improve mathematics, logic, and statistical understanding as well.
If you are coming from the point of view of a shop or club and what rules you should run then I would personally recommend you keep to a strict enforcement of age limits for unaccompanied children. This is less about what the children are capable of and more about protecting yourself. If you are strict about the restriction you can always relax it for those individuals who have proven themselves to be reliable.
Lastly, as a parent I know my son (who is 10) can cope with playing D&D and 40K in an open environment but I would consider it irresponsible of me to leave him on his own even with other adult supervision. Unfortunately my experience of the Games Workshop environment suggests that if allowed many parents will happily dump children as young as 7 in such places if they think they can get away with it. :(
There are two things you should be looking at when looking at the "appropriateness" of a game, with a third one that might affect their fun, but not their safety.
First, are you okay with the game books? Second, are you okay with who they are playing with? Third, are they able to understand the rules?
First, look at the book for the game. Just because someone says a game is appropriate for an age group doesn't make it okay. I would avoid allowing children to play DnD until they are 10-12ish and maybe later depending on many factors. Some things I look for are, does it encourage players to be "bad guys," are you comfortable with the art, is it too sexual, or violent?
Second, This is THE most important thing for you to look at. Who will they be playing this game with. A game that is innocent can be made hyper-(insert objectionable adjective here) by a group of players who are more interested in playing that kind of game. Get to know each person in your child's game group, particularly the Gamemaster, or Storyteller. Do you trust them? How about the other players, would you let your child play with them unsupervised in any other situation?
Third, when you look at the book, think about your child if they might have difficulty with they rules, they might not have much fun. There are some quite simple rules sets out there, and some that require a lot of complicated math to do.
Roughly, an age:
A hardline number is hard to give, but in general, the guideline I'd give is "once they are able to understand clearly the difference between fiction and reality."
For most kids, that's in place by age 12; many 7-8 yo kids can do so.
Generally, tho', most kids under age 10 simply are not ready for the tabletop mode of game, but some are.
Further, most games' rules are written at a high school reading level. If they can't understand the rules, they'll need some older help.
On the other hand:
Most children begin to roleplay with or without supervision between ages 3 and 5. They just don't have specific rulesets, merely conventions of playing house, cops-n-robbers, cowboys-and-indians, martial-arts-uberheroes-and-villains. Most kids are doing some form of roleplay by the time they hit kindergarden, and often during preschool.