The Ultimate DOOM

The Ultimate DOOM

128 ratings
How to run ports\mods through Steam using ZDL
By Milberry Frog and 1 collaborators
A guide to help people run modern Doom ports through Steam using ZDL, this enables Steam Overlay in the modern ports.

For those of you who are comfortable with this sort of thing, simply place ZDL in the base folder of any Steam Doom game and rename ZDL.exe to DosBox.exe.

For those who know nothing about Doom modding (ports, WADS, etc.) hopefully this guide will be of some help.

NOTE: It seems that for some reason the Steam Overlay will not work with Doom 2. Hours will still be tracked but you will not be able to take screenshots using the Steam Overlay or receive messages from your friends.
What you need
Doom\Hexen WAD
These are located in the Steam game directory. Easiest way to find this is to go to your game Library and right click the game (Ultimate Doom for example) and choose Properties. From here click on Local Files, then Browse Local Files.

The WAD file will be in the folder called Base, for Ultimate Doom this is called DOOM.WAD, for Doom 2 DOOM2.WAD, etc...

A Modern Doom Port
There are many to choose from, for a full list see the Doom Wikia[]. I will only mention the popular ones here.

Chocolate Doom[]: This port tries to emulate Doom as close to how it was originally played as possible. It is low-res and 'ugly', just like back in the DOS days.

GZDoom[]: This is a more modern OpenGL port. Very popular for mods, if you want to play Brutal Doom this is a good choice.

Zandronum[]: Formerly known as SkullTag, this also supports Brutal Doom and other popular mods. It has a fairly active online community through Doomseeker (bundled with the install).

Odamex[]: I don't know much about Odamex, my impression is that it sits somewhere in between Chocolate Doom and Zandronum but I could be wrong. It appears to be Multiplayer focused and supports widescreen etc. but attempts to keep a classic Doom feel at the same time.

A Launcher Utility
Again there are many, for this guide I will use ZDL[], specifically Q's New Version.
Installing Ports and Storing WADS

Now Install the ports you downloaded from the What you need section of this guide. You don't need all of them just the one's that interest you.

I recommend installing them in a complete Doom directory, as this will make messing around with Doom much easier. I use C:\Games\Doom\ports to store the various ports that I use.


Copy or move the WADS you found through the What you need section of this guide.

Again I recommend storing them in a separate folder, this will make it easier for ZDL and other programs you use to find them. I use C:\Games\Doom\WADS to store all my official Doom WADS.


I also use C:\Games\Doom\PWADS to store custom content, such as mods, maps etc...
Installing ZDL
Replacing Dosbox.exe

In order to run ZDL directy through Steam we will replace the DosBox executable provided by Steam. This is not illegal so do not worry about VAC, Steam provided you with an emulator called DosBox, we are simply replacing it with a more efficient and Windows 8 friendly alternative.

  • Using the method outlined in the What you need section of this guide, find directory of the game you want to use. I personally use Ultimate Doom but it doesn't matter.

  • Open the folder called Base and delete all the files inside. Alternatively, if you want to keep them, simply rename DosBox.exe to something else (old.exe for example).

  • Now unpack ZDL into the Base folder and rename ZDL.exe as DosBox.exe. If you can't see the .exe extension don't worry, just rename ZDL to DosBox.

    You are almost done, if you hit Play now on the game you chose to replace (play Ultimate Doom for example) it should now bring up ZDL and show your status as playing a game. If not something went wrong, read over the guide again and make sure you didn't miss anything.

    Setting up ZDL

    On the window you will see a bunch of garbage (-conf, -fullscreen -exit) highlight these and delete them by hitting Rem. Unfortunately Steam adds these each time you launch the game, just delete them and hopefully we can find a way of blocking them in the future.

    Now, you should see a Main and Settings tabs, hit the Settings tab. Here will be two boxes, one titled Source Ports\Engines and IWADS. Both these boxes will have Add and Remove buttons.

    For the Source Ports\Engines hit the Add button, name the port (GZDoom or whatever you have chosen) and then hit Browse and select the executable of the port you want to add. For me this is C:\Games\Doom\ports\GZDoom\GZdoom.exe

    For the IWAD hit the Add button, name the WAD (Ultimate Doom or whatever you have chosen) and then hit Browse and select the WAD of the game you want to add. For me, selecting Utlimate Doom this is C:\Games\Doom\WADS\DOOM.WAD.


    It should now be easy switching between various ports, mods, and WADS. Hit the Main tab and select the Source Port you want to use (GZDoom for example), below this select the IWAD you want (Ultimate Doom for example) then hit Launch and you are done.

    If you want to play with mods such as Brutal Doom simply hit Add under External Files and select the mod file. I store mine in C:\Games\Doom\mods. The little arrows next to the Add\Rem buttons allow you to arrange the order of mods, the lower an item is on the list the more important it is.
How to Restore Everything.
If something went wrong, or if you just want the games back to normal here is what you do.

Right click the game in Library and select Delete Local Content. Browse to the game directory and manually delete the folder if it still remains. Now you can re-install the game and it will be back to normal.

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Kroomask Sep 7, 2017 @ 11:50pm 
I discovered the problem, i put all the files in the folder, and for some reason, that sets steam off to redownload all of the files.
Kroomask Sep 7, 2017 @ 6:08pm 
How do i fix this problem?
Kroomask Sep 7, 2017 @ 6:07pm 
I tried doing this, but when i replaced the base folders and i started it up, all that happened is that steam deleted the zdl files and re-downloaded the dosbox files.
Lejionator Sep 7, 2017 @ 6:04pm 
Yeah, this is because that a launcher for Doom is a must.
Steilon Aug 11, 2017 @ 2:55am 
I was thinking of Hdoom but after this? uhhhh maybe not dood.
Milberry Frog  [author] Jun 2, 2017 @ 9:20pm 
Don't worry it's not the most clear guide and modding modern games is so much simpler by comparison. There's so many mods for Doom too now :D
symphonyofwar64 Jun 2, 2017 @ 9:16pm 
Ooooooh cool! Sorry, I'm a first time modder. Gonna make my first attempt over the weekend. Thinking of Meta Doom, Project Brutality, Complex Doom, or one of Pillowblaster's masterpieces. (probably Guncaster.)
Milberry Frog  [author] Jun 2, 2017 @ 9:03pm 
Ah I see what you mean, you only need to copy the WADS, not the entire game. This lets ZDL access all the WADS from one folder, rather than having to direct it to many different folders.

WADS are basically the guts of the game, all the Levels, Art, Sound etc.
symphonyofwar64 Jun 2, 2017 @ 8:49pm 
You said, in the tutorial, that you use 'C:\Games\Doom\WADS' to store all your official Doom WADS. Now, I've tried installing the games and making a new Steam Library on the C Drive of my computer, but it tells me that a steam library already exists, so I can't make another one on this drive.

Do I just manually copy over the doom games to a 'C:\Games\Doom' folder?
Milberry Frog  [author] Jun 1, 2017 @ 10:16pm 
Sorry but I'm not sure what you mean. Are you trying to install Doom through Steam into a seperate folder? I 'think' Steam can only install games all into the common folder, so you might have to re-install Steam into the directory you prefer.

If you just want to move the Doom games into a new folder, you can just drag the contents wherever you like and run the games from there, but you'll be running them without Steam in that case.

If Doom is just refusing to install, you can try to right-click on the game, select Properties > Local Files > and Verify Cache Integrity.