Left 4 Dead 2
Disabling the hud in Left 4 Dead 2 is convoluted and will only work under very specific circumstances.
Find and edit your autoexec.cfg with a text editor (like Notepad or Wordpad).
Add the following commands:
bind "f1" "sv_cheats 1"
bind "f2" "sv_cheats 0"
bind "f3" "r_drawvgui 0 ; crosshair 0 ; cl_glow_blur_scale 0"
bind "f4" "r_drawvgui 1 ; crosshair 1 ; cl_glow_blur_scale 1"
Now, edit your listenserver.cfg file and also add these lines (Will NOT work without this):
For some reason the developers classify those console commands as cheats (except for the crosshair command). Sadly, you cannot enable cheats in a regular single player game.
To play the game without the hud, you have to bring up the console at the main menu (Should already be visible now that we enabled con_enable).
Names of maps will appear. To start on the first level enter:
Levels are in numerical order: c1m1, c1m2. . . c2m1, c2m2, etc) This way you can go to any level, which is good because you can't save or pause your game.
The original Left 4 Dead levels were ported to L4D2. Those levels start at c8m1.
When in game, press F3 to disable the hud, F4 to enable hud
NOTE: this method of disabling the hud also removes the menus, so use F4 to turn them back on when needed.
Other flawed console commands:
cl_drawhud 0 - only disables part of the hud
hidehud 4 - removes the hud, but also disables weapon switching.
crosshair 0 - Removes crosshair
cl_glow_blue_scale 0 - Removes glowing around npc's, players, and items.
r_drawviewmodel 0 - Removes weapon from view.
If you have random beeping or static sounds in game, rename this directory: