Quake 3 Tweak Arena - Demo explanation...

• Recording a demo:

  To record a demo, firstly start either a single player game, or a multi player game against others. Now, open   the console and type "g_syncronousClients 1" ( minus the quotes ). This will ensure that all the players are set   up correctly in sync so that the demo records and plays back correctly. Please note that this may impact   FPS, but this setting is required for a demo to be recorded.

  Now, when you are ready, type "record <demoname>" where <demoname> is the name you wish to call the   demo. Now the demo is recording. To stop the demo, type "stoprecord" into the console.

  You can now select your demo from the demo menu on the start screen.

• Recording tips:

  It is all very well using the console commands to start and stop a demo, but it is quite unpractical and fiddley.   It is far better to create keyboard binds used exclusively for starting and stoping demos. To create the binds,   place these commands into the config:

  bind F5 "record"
  bind F6 "stoprecord"

  Of course, you can use different keys instead, but I find these the easiest to use and remember.

• Playing a downloaded demo:

  To play a demo you have obtained from somewhere else, you must first create a new folder in your baseq3   directory called "Demos" ( minus quotes ). Next, you should place the demo file into this folder and then start   up Quake 3. Go to the Demos option, and you should find the new demo in the list of demos available. It   should be called whatever it's filename is in the demos folder.