Although the original Call of Duty does not natively support most modern resolutions, that does not mean it's impossible or even hard to play in your desired resolution.



The first step to play with your desired resolution is this command that enables the custom resolution function:


The second step is to decide what resolution you want to play with by assigning the desired width and height using these commands:
Some common resolutions are 1920x1080 and 2560x1440, where the number on the left is the width and the number on the right is the height.
Remember to not mix up width and height or there may be unforeseen consequences!


The third step is to set the aspect ratio of the resolution to make sure everything scales correctly:
The number you are supposed to set this to depends on the aspect ratio of the resolution.
4:3 uses 1.3
16:10 uses 1.6
16:9 uses 1.7
If your resolution is not one of these three aspect ratios you can calculate the aspect ratio decimal by dividing the resolution's width by it's height.


The fourth and final step to playing with your custom resolution is to put everything into the Launch Options.
It should look something like this:

It's possible to skip the intro video that plays whenever you launch the game with this Launch Option:
Skipping the introduction video that plays some sound and developer logos saves some time and loads the main menu faster.


It's possible to change the game's field of view (FOV) to your preference with this Launch Option:
The field of view (FOV) is by default set to 80.
Higher FOV values might break the game's view models and reload animations!


As long as you disable Sync Every Frame in the game's options menu it's possible to limit the game's FPS with this Launch Option:
By default the FPS limit is set to 0, which is uncapped.

Finding and editing the game's config file isn't actually all that hard or complicated but there is no need to worry about any of that, because we have Launch Options!

Launch Options are a lot more straight forward than editing config files, all you need to know is what modifications are available so you can type them into the Launch Option depending on what you want.



To input Launch Options all you have to do is right-click the desired game in your Steam Library and click Properties...

Then you simply write the Launch option(s) you want here:

Launch Options will not automatically transfer between the Singleplayer and Multiplayer Call of Duty clients, so remember to launch the version you want to play directly through Steam rather than from inside the game client.




Now go and play the original Call of Duty experience in your desired resolution!