How to play Doom online multiplayer

Doom is one of the first games that popularized online multiplayer. It comes with native cooperative and deathmatch support. Modern source ports add new gameplay elements and modes such as Capture the Flag and Survival. The three most commonly used mutliplayer source ports are Zandronum, Odamex and ZDaemon.

A browser is required query each port's master server. Internet Doom Explorer (superseded by Doom Explorer) is compatible with the above three ports and features an integrated IRC client with built-in links to their channels (#zandronum, #odamex, and #zdplayers respectively). Doomseeker is an alternate multi-platform server browser.

Note: If you intend to host a public, you will need to. A helpful article on port forwarding can be found here. IDE and Doomseeker both allow easy configuration and launching of custom servers.

Set program directories
Open IDE and click the Options tab at the top. Click Programs, under Directories in the left-hand column, and you will see:



Click "..." to find your client and server for each source port.

Set preferences
Click the Launch Game Parameters option at the left.



You can enter your online username and set your player color for each port by clicking the marine icon. Zandronum allows you to use colored text for your name if you wish.

The WAD check and Zandronum autotesting options are recommended. You can also choose to record demos of your online matches.

Set WAD directories
On the left hand side, click Directories, then click Wads.



Click Add. Add each source port's directory to the path list, as well as your main PWAD folder, if you have one.

Configure GetWAD
GetWAD is a utility for automatically locating and downloading any add-on content required for your online session. Most servers use custom WADs, so this is an important step.



On the left-hand column, under Optional Components, click GetWad. Here you configure where new WAD files will be saved; you must select one of the directories you chose in the previous step.

Configure server list
This will control how servers appear to you and make it easier to find the exact game you're looking for. Click Appearance & Functionality on the left.



Check Additional sort by players number and Don't sort servers with only bots to move populated servers to the top of the list. Check Refresh the server before launching the game to see the current number of players when you connect.

Create a ZDaemon account
ZDaemon keeps track of experience points for many deathmatch and duel servers, as such it requires an account. Click the ZD Scoreboard tab at the top of the IDE toolbar:



Here you can enter a name, password, profile blurb and instantly create an account. You must use the same name you selected under Launch Game Parameters.

Connecting to servers
Click the Servers tab at the top, being sure to enable all three source ports. Click Players to sort by number of players,  to sort by connection quality, and so on.



Simply double-clicking any server will connect you and automatically download all necessary WADs.

Server hosting
Multiplayer oriented source ports all you to start your own server with custom WADs and rules. Citadel Servers offers Odamex game hosting rental and The Sentinel's Playground allows users to start remote servers for free.

Video tutorial
Video tutorial by Doomkid:

Using ZDoom
For instructions on setting up netgames, see at the ZDoom forums. ZDoom players cannot join in the middle of a game, all clients must be ready at startup.

Using Chocolate Doom
preserves a faithful vanilla Doom experience easily on modern PCs, updating and automating most of the networking setup, and avoiding the CPU slowdown of full emulation (see "DOSBox" below).

One player must act as the server and host the game. To run a Chocolate Doom server over the internet, you need to know your public. Some providers use, so the IP in your OS control panel may not be what the rest of the world sees. whatismyipaddress.com, for example, can determine your public address.

When you start a server it is automatically registered with the master server. Other players can use the setup tool to find your server, or you can check for its address on the master server's website. If the server doesn't appear on the list, it's probably because you haven't properly set up the port forward for your NAT router (see above).

Start a multiplayer server by launching Chocolate Doom with the command line option. For example, to start a server for a deathmatch game, type chocolate-doom -server -deathmatch.

Other players can then join your server using the option. For example, if the server's public IP address is 123.123.99.99, type chocolate-doom -connect 123.123.99.99.

When the server becomes active, you will see the "waiting" screen which lists all players currently connected. Once all players are present, click the start game button (or press the space bar) to start the match.

Using vanilla Doom
DOSBox is an emulator capable of running the original DOOM.EXE and DOOM2.EXE.

First, install DOSBox and mount the directory containing the Doom executable and IWAD(s). If your computer is behind a, you must also have opened ports.

To allow connectivity, edit the DOSBox config file. For default Windows packages, this is within the DOSBox application folder and has a name like or. Open this in or another text editor. Near the bottom should be the line ipx=false; change this to ipx=true.

On the hosting PC, type ipxnet startserver , where is the you want to host with.



On the connecting PC, type ipxnet connect  , using the same port number and with the host computer's IP address as . This works over the internet as well as on a. If someone has set up an internet server, type the IP and port which they have specified. The IP and port must have a space between them, not a colon as in most source ports.

You can then launch a game, loading any PWADs (which must already be in the same folder as the .exe) and configuring coop or deathmatch play using Doom's standard command line parameters.

Using Doom Legacy for splitscreen matches
Doom Legacy has a splitscreen mutliplayer support. Version 1.42 of Legacy is recommended for its stability and simple launcher.

Install the package and open the launcher:



Click Game Mode. Tell the launcher where your Legacy program and IWADs are. It is best to put all IWADs and PWADs in your Legacy folder.



Now click Single Map (but not Multiplayer).



In the Additional options field, type +splitscreen 1 and, if you want to deathmatch, +deathmatch #, where # is a value between 1 and 3. Typing no commands will start a cooperative game.

In the Additional files field, select a PWAD if desired.

Set each player's controls by pressing Esc, then selecting Multiplayer to configure player 2. Now click Launch to begin play.

Four-player game using two PCs
Start Doom Legacy through the launcher as described above. When the game starts, hit Esc, select Multiplayer, and select End Game. You should now be at the title screen. Press Esc, select Multiplayer, select Start Server, and enter a server name. (On this screen you can also set additional game options, such as no monsters mode or item respawning).

On the second PC, start the game through the launcher with the same WADs as the host. On startup, press Esc and select End Game. Now press Esc, select Multiplayer, and then Connect Server. The server name should be displayed; select it and hit Enter.

Now go back into the game on each PC and open the console (tilde key, ~ ) and type splitscreen 1. Configure the second set of controls by pressing Esc, selecting Multiplayer, then Setup Player Two.

Using console controllers
Zandronum is the only multiplayer oriented source port with native controller support, however there are many keymappers availible online that can be used for any port. XPadder is one such utility, with support for or  controllers. XPadder costs US$10, and setup instructions are posted on its forums.