Note that many video and sound changes will not take effect until you restart the video or sound system with vid_restart or snd_restart respectively. If none are specified, it's a boolean variable, meaning it can be on (1) or off (0). Commands are listed without values, but some may have and/or, see the descriptions for valid arguments or values.
Variables are listed with their default values. Select the complete list (handy for searching for keywords using your browser, or for looking up a command or variable alphabetically), or any of the categorized lists from the links over to the left.
If you don't know how to get to the console, please read this. Use these commands and variables in the console or a config file to completely customize Kingpin, troubleshoot problems with video or sound hardware, optimize performance, or make your own scripts.