So there is a small chance of your child getting a Pokemon with an inappropriate nickname, and there is no way to change it's name if you're not it's original trainer. For example, twice I have gotten Pokemon named "KYS f4gg0t" (translation: "Kill yourself, f*gg*t."). You can't chat with anyone like in a chatroom or something, but some people will find creative ways to sneak in some inappropriate names for a Pokemon. However, exercise caution with this feature. It's a fun way to experiment with new Pokemon or find some that you haven't seen before. It's a feature where your child can connect to the internet and send off a Pokemon to a random player and receive another Pokemon from that player. There is just one problem I have found in the game, which is the feature called "Wonder Trade". It's not that the game is inappropriate for younger kids, it would just be difficult to understand. There's quite a bit of complex vocabulary and concepts that younger kids may not be able to grasp, and that may cause them not to enjoy the game as much as older kids. My reason for believing that this game is best for ages 10 and up is because younger children may have trouble understanding the game. I'll be focusing on my main issues with the game, and then the good points. I'm 19 years old and not a parent, but I am told I'm really good at decision making in entertainment, both for myself and children. There were rare event Pokemon on the GTS like a shiny Jirachi nicknamed Ebola n*gger and Anal Sex and those names are supposed to be blocked but these were posted by hackers as Jirachi and other events aren't usually supposed to be nicknamed (there's exceptions for events from previous games where you get an item and catch it yourself but Victini was the last of those). And I'm editing to bring up another issue that another reviewer brought up that I have had issues with myself and that is the inappropriate nicknames on wonder trade and even on the GTS.
And the game has a function that WILL make it difficult to reject friend code requests by these strangers called the Friend Safari which allows you to catch special Pokemon that are tied to a registered friend code and the Safari is unusable unless you have a friend code registered.
So do NOT let your children play these games unless they are supervised or you have the parental controls set up as some of these strangers do try to get phone numbers, addresses of where your child lives etc.
Okay now hear me out when I say that this is a dangerous game in the series because it allows your children to add complete strangers to their friend list after trading/battling at least twice and if they do so they can speak to these strangers using the systems microphone and there are perverts who occasionally target such children.