Many games allow players to host their own dedicated servers, as separate applications from the game client. Some games even allow players to modify the behavior of the server through scripting languages, allowing player-run servers to employ novel behaviors not originally designed into the game.
Let's see how we can set up a similar system in Unity. I will not be covering modding, although readers can look up Lua scripting in Unity—there are a number of resources on the topic.
Most games have a specialized "server" build, which contains much the same code as the client, designed to run as a dedicated server. This allows the server to process the same logic as the client.
Unity, however, does not ...