How can i make my game an online multiplayer just using some blueprints

I made a simple FPS in Unreal Engine, but it is a singleplayer game. Can i make some blueprints for the game and make it an online multiplayer?

P.S: Sorry if it is a stupid question, i am new to game development and just need some help. :slight_smile:

Yes, it easier then you think. There many methods of making network multiplayer UE4 (but you knwo you can laways build your own system of corse that would require C++ work) uses so called replication, where clients tries to replicate state of server while sending own state input, trying to keep game state in sync in both server and all clients connected.

Replication is very seamless, thanks for reflection system and already existing multiplayer code in the engine. Only thing you need to do is to make your code (blueprint or C++) multiple player aware, your code need to be ready that there gonna be 2nd and more players in area interacting with things.

Most impotently you will need to deal with multiple player controllers, each player will have one and each steers possess pawn, so you wont be able to use GetFirstPlayerController (or Get Player Controller with just imputed ID 0), you will need to get Player Controller from the pawn with Get Controller node. It also importent to understand that GameMode, GameInstance and PlayerController (except of Player Controller of local player in client) are only existing on the server, so only code execute on server can access those, they are not replicated, only there actions on server are replicated, this is for security reasons so player can’t hack those from there machine.

So make your code aware of more players, place more PlayerStarts on map start a server and connect the client and it should work. Once oyu got that you can refine things by deciding which variables and function need replication or not, cosmetic things like starting particles and such should run only on client, while server don’t need any visual code as it only operates state of the game. You also need to think about security, you can’t provide hidden data to clients that should not have such data (like heath of enemy player) even if you don’t display it it will be in client memory and players can access that thru external software, you only helping cheaters if you don’t control such things.

Here you have info how to start server (both player host or dedicated server):

Search for “UE4 replication” for any tutorials. Also once you setup multiplayer game you will need to think of some online service (like Steam) to connect players together, or else your users will be forced to use manual IP addresses lists like Minecraft does, read about OnlineSubservice for this. Btw LAN game browsing don’t need online service, this will work out of the box in NullOnlineSubsystem.