Complete list of console commands: FAQ with some technical info:
The game uses non-power of two textures for models, which were supported by the software renderer, but not by the OpenGL renderer. Therefore, textures in OpenGL have to be resized to a power of two; this is controlled through the console command gl_round_down. By default this is set to 1, which downsamples textures to the nearest power of two, reducing quality noticeably in the process. This was used due to limitations of contemporary 3D hardware.
Setting gl_round_down 0 (and doing a vid_restart, or putting it into an autoexec.cfg) improves texture quality noticeably.
The ingame method uses a simple linear filter; an alternative exists in the form of the mod "Quake II Facelift", released in 2007, which supports Lanczos upsampling for even further improved texture quality. It also includes several other changes, like an implementation of the water screen distortion effect from the software renderer, an option to toggle texture filtering off (via setting the "8-bit texture" option to "on"), and desktop resolution support (via selecting sub-640x480 resolutions).
This mod also has a few shortcomings; widescreen support is essentially broken as objects disappear at the left and right edges of the screen, so keeping to 4:3 resolutions is recommended. Also, load times between levels are increased, text and HUD elements are forcibly upscaled and look rather ugly, and the brightness setting now affects the skybox.
Since the release of the source code various engine overhauls and source ports have been created to enhance or modify the game in different ways. Which one to use is a matter of taste.
Some multiplayer servers require clients to use the r1ch.net anticheat module, supported source ports are listed on its website.
Use the MarkC Windows 10 + 8.1 + 8 + 7 Mouse Acceleration Fix.
If you are getting "function pointers have moved" error in console after trying to load game, install fan-patch 3.24. Issue noted in GOG.com release.
The music plays directly from the game-CD so the Steam version unfortunately lacks it. Try applying the Ultimate Quake II patch mentioned above.
If you prefer to use the original engine you can download the soundtrack from the Steam discussions.
Either burn a new CD from the image file or use a CD emulator like WinCDEmu to mount the image.
GOG.com version does not require this method, as the whole soundtrack is in OGG format, which the game was modified to use it instead.
Use the following command line arguments with kmquake2.exe:
+set game xatrix
+set game rogue
echo Quake II + expansions
echo 1: Quake II
echo 2: Mission Pack 1: The Reckoning
echo 3: Mission Pack 2: Ground Zero
set /p userinp=choose a number (1-3):
kmquake2.exe +set game %game%
00 00 B4 42
00 00 33 43
This problem occurs only if you try to run the main EXE file. It must be ran from the Launch Quake 2 shortcut to make it work. This is due to the fact that it contains a code in the Launch options.