Known as MMOs, online multiplayer games are also sometimes called "Massively Multiplayer Online Games" or MMOGs, or "Massively Multiplayer Online Role-Playing Games" or MMORGs. Regardless of their name, these games let kids go online to play with thousands of other players from around the world. In these online game worlds, you create an avatar to represent you and join others to go on quests or missions. Some are free, whereas others have a monthly fee or require you to buy things while inside the game. Most offer some kind of chat, so pay attention to your kids' interactions.