This is a hard question to explain because English is not my first language. I have a game coded with socket.io that uses a persistent world. When a player clicks play, he enters the world and can manipulate it like singleplayer Minecraft. However, many other users can access the server at the same time and modify the world so that the first player sees modification, but none of the players can see each other. All enemies, bullets, etc are only for each individual player. Players only can see world modifications of other players. I want to make it so groups of 2 players can player simultaneously. So these 2 players can see each other as well as world modifications of all other players. Would I just have to have multiple servers? I want to just use the 1 server to let groups of 2 players to play the game like how solo players play the game now. I can't afford to host many small servers.