276 ratings
How to Do Multiplayer Co-Op
By -={D@}=- The009®
This guide will help you start and play a Multiplayer Co-Op Game.
I will go over the ports and steps needed for this all to work.
Port Forwarding
In order to host a game you will need to forward the following ports.
These ports are used by the Steam Engine and they are used for all of valves games.

  • Steam_1 TCP 27014 - 27050
  • Steam_2 TCP 3074
  • Steam_3 UDP 27000 - 27030
  • Steam_4 UDP 3478
  • Steam_5 UDP 4379 - 4380
  • Steam_7 UDP 3074

If you do not know how to forward the ports on your network you can go to http://portforward.com/ and they can help walk you through the settings for your router.
Hosting The Server
From The Menu Click On "Host New coop Game" and A small window will pop up.

On The First Screen Of The Pop-UP select the first map on the dropdown list.

Then on the second screen you have the option to add a password.

Once you have done that simply press start.

This will take you to the lobby screen.

If your name shows up as Unknown in the lobby screen press the ~ key.
In the console type
name "<your_Name>"
and hit enter.

Now that you have the server running your friends can connect to you.

You can also send a heartbeat to the steam servers to get your server listed for others to play if you do not add a password.

To send heartbeat open the console with ~ and type in
and press enter.
This will send a signal to the servers saying that your server is up and running for others to play.
Friends Joining Your Server
If you have set a password for the server your friends will need to enter it in the console.
Press the ~ key and in the console type
sv_password "<your_chosen_password>"
and hit enter.

Now they have set the password for the server it is time for them to connect to you.
You will need to know what your ip address is. If you do not know what it is you can go to http://whatismyipaddress.com or https://www.google.com/search?q=what+is+my+ip.

Now with your IP address have your friends type the following into the console.
connect "<your_ip_address>"
and hit enter.

You should now see your friends in your lobby.
Once everyone is in you just need to all press the left mouse button and the game will start.

Enjoy your Co-Op Fun.
< >
Atheldra Jun 14 @ 5:23pm 
thanks dude
-={D@}=- The009®  [author] Jun 14 @ 4:30pm 
@Atheldra Press ESC to bring up the menu, then host new game, that will take you to the above info, Do not press start untill people have joined you :)
Atheldra Jun 14 @ 9:45am 
i start and I am immediately spawned. How do I go into the lobby?
Verrückt ♠ Apr 22 @ 2:58pm 
can someone just make a server so we can play? -_-
-={D@}=- The009®  [author] Nov 1, 2014 @ 11:10pm 
@H2ODelirious - Using Hamachi is still a valid way for people who can't port forward. There are many tutorials on how to properly setup hamachi and your other network interfaces to work with gaming and hamachi and the net all at the same time :)
CaptainDreadfulTheSupamida Nov 1, 2014 @ 8:24pm 
I mean internet
CaptainDreadfulTheSupamida Nov 1, 2014 @ 8:24pm 
Well if you use hamachi it will fuck up your computer
♠ Teadrinking Komododragon Aug 30, 2014 @ 3:26pm 
Well.... It didn't work... What am I missing here?
Mr. Jackhuahua Aug 15, 2014 @ 11:27am 
Fuck Hamachi.
♫{GameBuster}♫ Jul 24, 2014 @ 12:23pm 
oh ok thx :)