This guide is over 4 years old, so on 2021-01-22 I decided to revamp it. Clean it up a little, de-cringe it, and add some extra details for Linux/Proton players (like myself!)

Here's the thing: unless you're playing campaign solo, it's not possible to use "sv_cheats 1" and wreak havoc. But if you're hosting, say, a zombies lobby with friends, you may want to enable cheats anyways. Thankfully, a custom keybind will do the trick.

While in-game, you can simply open the console with ` and type out the bind command, which will save it to the game's config and enable it immediately. This will work without mods, without T4M, and on any OS. The command is:

That's it. Boom, you now have server cheats on a key. Of course you can change F6 to whatever suits your fancy. If you ever want to undo your work, just use the command "unbind F6" where F6 is again replaced with your key of choice.

Ok, but what if you want to do more than that? What if you want your server cheats bind to also be a godmode toggle, or to quickly change around a whole bunch of other settings at the same time? Well, you can do that in the game's config.
Before we go on, it's worth noting that changes to the config won't take effect until restarting the game (as far as I'm aware).

Chances are, if you're reading this gude, you've bought the game on Steam. Either way, you need to find the config.cfg file for your user. I'll run you down finding that on Windows and in Proton for the Steam version, but if you have the CD release, you're on your own.

Windows users, open up the file browser and click on the navbar to enter a location directly. You're gonna put this in:

For Proton users, you need to take note of your Steam games install directory. I have my games install to "/hdd/Steam" but if I recall correctly the default location is "~/.local/steam". You'll know you've got it when there's a "steamapps" directory in there, and inside of that is both "common" and "compatdata". I'll be using that "steamapps" directory as reference. So, navigate to:
(Note: depending on how you enter this directory, you may need to surround that with quotes or escape the spaces)

Now that you're in the sweet spot, open config.cfg with your favorite text editor, but don't use Notepad! vim, Sublime Text, VSCodium, and Notepad++ are all fine candidates; just use something with LF line endings instead of CRLF (if that meant nothing to you, don't sweat it, just don't use Notepad). Is this absolutely necessary? I'm not sure. Probably not. I can only tell you what definitely works, and those definitely work.

The top line tells you not to mess with the file, and we'll be ignoring that warning. This is not a bannable offense, so don't worry about that.
(Note: I've never played W@W's multiplayer. I doubt this would work to activate cheats there, but if I were you I wouldn't push my luck!)
Find a good spot among the existing binds to add a new line, which will be:
Oooh, we get quotes this time! Again, switch F6 with your key of choice. You can unbind the key by removing that line.

You can also add multiple commands to one bind! Inside the quotes, put a semicolon after a command (you might also need a space, I'm not sure; I just put them there anyways) then the next command. You can do this indefinitely, as far as I can tell. Here's an example from my own config:
This lets me enable cheats on-the-fly, gives me a visual indicator that they're on, and also provides a convenient godmode toggle button.

As long as you're in here, why not add some more cheat binds? I have F1 through F4 bound to other cheats, including "cg_fov 90". Go nuts!

Anyways, when you're satisfied, save the file.

If you're doing this just for FOV, then you should instead install T4M[www.ugx-mods.com]. This makes "cg_fov" changes available without server cheats, and is a dependency for most mods nowadays. I only know of one mod that advises you not to use T4M, so what do you have to lose?