Thanks for the replies. That was very helpful.

if you use mods you all need the same mods or it wont recognise them or let them connect

I have been playing with 3 people at the same time without a dedicated server in the past, and I can probably have more people at the same time if they are within Europe region.
The only negative side using your own computer as a server is that you have to schedule the game with your friends as you probably allready know.

Simple to do and no fuss.

I forgot to mention that the server package is only necessary if you plan on letting people play on your map when you're not on, or if you want a machine other than the one you're running the game from to host the map. If it's only going to be accessible when you're in-game and you don't need an additional computer in the mix, then just the client will do (you can launch the map into a mini server straight from the local tab in the game client - just keep in mind that said mini server shuts down when you exit out of the game).

I know that I can set up my local game as a shared experience if I copy down and give my friend the IP address. However the moment I shut of my game all my friends are ejected if I am hosting.

As for a LAN I haven't had friends anywhere near me geographically in years so I don't even know if those are possible anymore.

Sorry I wish I could have been more help.

The server software is included in the purchase. You can run it on either a rented/remote-hosted server or on any machine within your own LAN. As long as everyone that you want to include knows the domain name (or IP address), port number, and password for the map's server instance, they can play.

On the multiplayer tab when you start the game, there is a button specifically for entering the address:port of your target server. You do not have to go through the "official" server listings if you don't want to.