[2023] how to play multiplayer

If you want to play "peer to peer" and you are running the game through your steam account, it will use SteamP2P which will "tunnel" through the internet, so you don't need to "forward ports". This isn't the most efficient way to host if you will have many people joining, but its much easier than running a dedicated server, or using port forwarding.

If your router has UPnP, the game will try forward ports as well using that.