SV_MAXSPEEDand other variables
One of the reasons that id Software's products have been so successful (apart from their technical excellence) is that they are very easy to modify. Quake in particular allows a huge variety of changes to be made to the way in which it runs; indeed, a lot of the mechanics of the game are coded in the specially designed language Quake-C, so that users with some meager programming skills can rewrite them as they require.
But one does not need to learn a programming language in order to make dramatic alterations to Quake. Within the game itself, the console allows you to reconfigure many aspects of the game. The console has four main uses.
In DeathMatch competition, this is not an issue. All clients play off the same server and so they have a common set of variables; and of course these can be changed only by the individual in charge of the server. However, in single-play competition (challenges and contests, normally run against the clock), every client has control of their own server, and so it is feasible for them to do whatever they like. Therefore, to ensure everybody competes on a fairly level plane, changing server variables in single-play competitions is usually considered to be cheating. If you want to play Quake, play Quake, not your own special variant!
SV_MAXSPEED is a server variable (hence the
SV prefix, with which most - but not all - server
variables start.) It places some limitation on how fast the player is
allowed to run by trying to keep their velocity under 320 pixels per
second. So although increasing this variable would let one run faster,
no-one would accept this as a reasonable tactic. It can't be done in
DeathMatch and should be considered similarly off-limits in