How can we keep our kids safe on Minecraft?

To expand on 's excellent answer; the best way to know you have a minecraft server administrator who cares about the server being kid-safe is to be the admin yourself. It doesn't cost a lot to rent a minecraft server, at the low end $4 to $6 a month. Then you have complete control over who can access the server, plus access to things like chat logs, as well as the settings of the server and what mods are installed. Since you control the server, you can give access to your children and their friends and not worry about the behavior of random people from the Internet. This also has the added effect of making you the coolest parent around. "I got you your own private minecraft server for you and your friends to play on. " There are a lot of different hosting companies out there. Just as Cliff suggested with public servers, I recommend talking to the company you would be renting and have them help you get the server configured in a way that gives you access control.

Know who's running the server(s) that they're using, and monitor their usage (just check in on them from time-to-time).  There are many family-friendly Minecraft servers out there, that act on a "whitelist" basis (you have to be approved to play, and violations of protocol get you banned quickly. Here's one such site from a quick Google search - http://www.sandlotminecraft.com/ - I don't necessarily endorse that site, as I literally know nothing about it, but I know there are similar hosting services out there to be found.

One option is to find (or create) a special "kid-friendly" environment. Servers such as this exist, and for some, using one of those can be the right choice.That's not been my approach.I've opted to use ordinary public minecraft-servers. I don't want to shield my children from the "real world", instead I aim to do my best to teach them how to deal with reality like it is, including the rough parts: I've read through the rules for behaviour on servers with them, discussed them and asked questions such as: "Do you think these are good rules ?" "Do you think you'd have more fun, or less fun, if being rude is allowed on a server?" I play -together- with them sometimes. This gives me some idea what the environment is like. Even when I don't play with them, they most often play in the living-room together with us adults, and we communicate about things that are going on. We talk about strategies for dealing with unwanted behaviour, and about what things you should avoid doing not to put yourself at risk. That's it really. Maybe we've been lucky, but it seems to me that most server-admins are concerned with making the environment friendly and welcoming and as such problems have been few and far between. (and in most cases caused by my own kids having imperfect knowledge of the mechanisms and rules: "Why did he steal my gold ?????" --- hi, did you consider using /protect on your chest if you didn't want it to be for public use ?" kinda situations that caused some frustration but nothing I'd consider abusive or harassing.)

inappropriate things will appear in your children's lives. its just what society has in it . I think you have very good values and good morals. i like all of them. If your kids pick up any of the behavior you do not want to tolerate in the house discipline them . if they are picking up bad behavior from these games and know that this behavior is not allowed or acceptable with in the family rules they should know better . taking away the privilege to game and grounding them from it because they can't be mature enough to abide by the house rules in one thing you can do . being honest and telling them how you feel is another, " hey I know you guys like these games and I want to see you two having fun , but there are some things on here that worry me. Id really appriciate it if you two could try and stay away from those things ? and then point them out  and let them know the dangers of what each on is related with . "

If they want an internet multiplayer game, get Realms, where you control who is playing. Play WITH them, and invite their friends to play as long as they follow the rules. Revoke temporarily or permanently invitations of players break your rules. Get your kids discussing the rules with you, and make sure you always know who are the approved players.Realms costs about $8 a month, and is very easy, you don't need any technical skill to set it up. It's essentially your own private server where only people you invite can play.

Mojang offers "Minecraft Realms", which is a subscription service that's very reasonably priced. If you know other people at your kid's school or in the neighborhood, consider using "Realms" and letting only people you know log in to the server.   The advantage of this is that you don't have to personally do a lot of server maintenance. If you want, you can use a pre-made world, or simply upload one that you like, and then let the kids take it from there.

My son plays daily and he's almost 9 . Best way to keep them safe from the vulgar players is to limit what videos they watch on YouTube . I monitor what he watches to make sure it's not something other than whats in the description . For example my son also plays Skylanders , so he watches Skylander boy and girl on YouTube which is suitable .  For minecraft it's always Stampy Cat . Myself I play World of Warcraft so I've seen the worst in kids and adults when it comes to gaming . Monitoring YouTube channels and who they invite online to their worlds in Mincraft.