The last resort. Face it -- going toe-to-toe with the uglies in Quake demonstrates all the good sense of a man parachuting into an alligator farm.
The Axe is Quake’s melee Weapon. It does moderate damage and should not be used unless you find yourself in sudden close combat with few Shells. It's also useful to open secret doors and is an alternative if you do not wish to waste ammo.
There is little valid reason to use the Axe in Quake, as ammo is usually plentiful especially for the Shotgun. This is in contrast to other first person shooters (including those by id Software) whose levels have a scarcity of ammo as well as a more powerful melee weapon. The axe should never really be used unless absolutely necessary.
You can save ammo by using it to hit buttons instead of shooting them.
The axe is useful in saving ammo against lone ogres. If you come across a stray ogre sneaking, pull out your axe, then run toward the ogre hit it once (or twice if you can time properly) then back just out of melee range, then run forward again and repeat. This is a time consuming method so it should only be used as a last resort.