A comprehensive mod loader guide

This guide will show you how to set up a mod loader for Doom & Doom II, which allows you to easily play custom maps & mods without needing to edit any files. (Thumbnail art by Nick Minor)

Folder setup & finding Doom wads

The very first thing you'll want to do is create folders to better organize your mod collection. Make a folder called "Doom mods" or something along those lines. Then inside that folder create three more, one called "maps", one called "mods", and one called "IWADS". The reason these should be separate is because in Doom modding there are map packs, which add custom levels & other huge changes, and there are smaller scale mods which just change aspects of the vanilla game without touching the levels. The IWADS are the original game's wad files that are needed for custom content to function. It'll be easier for you to remember which is which in the future if you set this up now.




An example of a smaller scale mod that adds Isabelle as a companion.







In order to even load mods however, you need to have the original Doom or Doom 2 wads so that the custom content can use the game's assets. The way you do this is pretty simple.

1. Right click on Doom + Doom II in your Steam library, click on Manage, then Browse local files.










2. Go into the rerelease folder and copy the doom.wad and the doom2.wad files, and paste them into your IWADS folder.






Now that we have our folders and wads set up, its time to download the programs that will actually let us play the custom mods.

Downloading software

There are two pieces of software you need in order to get started with Doom modding: GZDoom and Doom Runner.

GZDoom

GZDoom is a port of Doom that adds many new features to improve the game. Most maps made today use GZDoom in order to take advantage of these features. There are other ports you can use, but since GZDoom works with older maps and is required by a lot of modern maps to function, it's the port I would recommend.

To get started, go to the gzdoom website and click the downloads page. Here it is for convenience: https://zdoom.org/downloads. Under the GZDoom logo, click the link that matches your operating system. I don't use Linux (though I plan to someday), but I think the Ubuntu downloads will work for most Linux distros.










The GZDoom downloads.














Once GZDoom is done downloading, unzip its folder and put it in your Doom mods folder.

Doom Runner

Doom Runner is a mod loader that lets you load custom maps and mods without having to edit any ini files. Just like with GZDoom there are other mod loaders you can use, but I prefer Doom Runner because it's available on every operating system and has many quality of life features that make modding easy & convenient.






What Doom Runner looks like.











To download Doom Runner. go to its Github page https://github.com/Youda008/DoomRunner and click the Releases section.







Click on the link that applies to your computer. For Windows you want the 64-bit version not the 32-bit. Once that's downloaded you can unzip it and put it in your Doom mods folder. That's all the software we need! Now we just need some mods. Mods can be found in lots of places, but the two most common are Doomworld and ModDB. Mod files can be either .wad or .pk3. Do some research and find a few that seem interesting! Then put them in either your maps or mods folder depending on what type of mod it is.

Playing the wads

Now it's time to set up Doom Runner so we can play our wads! When you click the Doom Runner exe, you should see an initial setup screen that looks like this:



















Here's a step by step list of everything you need to do to set it up.

1. Under the engines section, click the green plus circle and go to the GZDoom exe and select it. This means that Doom Runner will use GZDoom as its port when loading any custom wads.

2. In the Directory with Maps section, click browse and select the maps folder that you made. For the Directory with Mods folder, select the mods folder you made.

2b. If you're on Linux, check the Use absolute paths box. Ignore this step if you're on Windows or Mac.

3. In the IWADS section, click the Auto-update IWAD list from directory button. Then click browse and select the IWADS folder that contains your doom.wad and doom2.wad files.

4. Next to Color scheme, click the Dark (override) bubble so you don't get flashbanged after playing wads until 2 in the morning like I did. You can also use the application style box to make Doom Runner look like an older Windows app if you want.

That's all you need to do to setup Doom Runner. In order to play with maps, just highlight the IWAD you need (99% of custom wads use doom2) and the map you want to play. To add gameplay mods, click the Add a mod file button under the Add mods section. Once you've selected what you want, press the Launch button!






Me about to play the Golden Souls map.











And to make a preset, just click the green plus circle under the Create preset section. I recommend using the Default preset to play the base games or short wads you don't plan on revisiting often, and creating new presets for longer mappacks or a favorite mix of maps and gameplay mods. You can get really crazy with these, so feel free to experiment! (don't be surprised if you get stuck though.)





A combination of myhouse.wad, the lasting light mod, and the Isabelle mod.

Bonus features

I've gone over everything that you absolutely need to play mods, so if you're happy with your current setup you can skip this part. If you want to tweak your experience a little more though, here are some optional adjustments you can make.

GZDoom graphics settings

GZDoom is a good source port, but it's default graphics settings are kind of bad. By default GZDoom upscales all textures in the game, making them blurry and distorted instead of the crisp and clean pixel art they are meant to be. Luckily there is an easy fix for this.

Launch a game using GZDoom, then go into options, then display options. Go down to texture filter mode and change it to None (linear mipmap). This will restore the game's art style and make it look much nicer.






The default upscaled textures.









The cleaner linear mipmap textures

Always Run

There's an option you can select that has you run by default instead of having to hold down shift, I would recommend this since Doom is such a fast-paced game. There are very few cases where you would want to walk in Doom. Also, if you're having trouble finding this or any of the other settings, there is an option search that will let you search settings by name.

Lighting fix

GZDoom also changes the game's lighting by default, making it look different from the original game. If you want the original look, go to display options and put sector light mode on Software.

Playing the official expansion packs

The process for playing the official expansion packs is similar to how we got the base game wads. Right click Doom + Doom II, manage, browse local files, and go into rerelease folder. This time though, we'll copy the following files:

id1.wad
plutonia.wad
tnt.wad
masterlevels.wad
nerve.wad
sigil.wad

Sigil is for Doom, while Nerve, Master Levels, Plutonia, TNT and id1 are for Doom 2. Put them in your maps folder and enjoy!

FPS display

Doom Runner has a setting that will display your current FPS in the top right corner of your screen when you're playing a wad. To enable this, go to Output options and check Show FPS.

[NavySpheal]

One thing to keep in mind that I briefly mentioned in the guide is that even though it's called Doom modding, 99% of mods are made for Doom II because it has more monsters & a new weapon. Unless you're playing Sigil or the mod specifically says otherwise, make sure you use Doom II as your IWAD.

[NavySpheal]

It's not very hard at all, Doom Runner makes it very easy to load up mods. You don't have to worry about load order; just click the mods you want to use and click launch! Plus I made this guide with modding newcomers in mind, which is why it goes over each step so meticulously. If you follow this guide you should be able to play whatever Doom mods you want. Try downloading a mod & lemme know how it goes and if you got stuck anywhere/need help.

[PhoenixASD5]

How easy would this be for someone who hasn't done that much in terms of modding PC games?

I've dabbled with modding Fallout New Vegas and that was an ordeal.

[Non-Employee]

Agreed, and being able to add separators to categorize presets (ie presets you're currently going through and presets you aren't) and my personal favorite feature is being able to duplicate and rename your current config, and automatically setting up separate save folders for each preset. I prefer having separate configs for my mod setups and that feature is a godsend.

[NavySpheal]

Thanks! I feel the same way about ZDL, it's a good mod loader & I used it for a while but then I found out about Doom Runner & haven't felt the need to use anything else. My favorite thing about it is that you can make as many presets as you want. Makes playthroughs of longer mods a lot more convenient!

[Non-Employee]

I was already going to like this guide since it's well done and will hopefully introduce some people to modding, but you get an award for using Doom Runner instead of using ZDL

(nothing against ZDL, I just prefer the features of Doom Runner and it's become my go-to mod loader after a lot of experimenting with others)