Bunny Hop

Basics
Bunny hopping is an old quake movement tactic. It means moving around by doing consecutive jumps. It makes the player harder to hit, and also gain speed. However, due to the stamina restriction for Humans, this tactic is rarely used in that team, but it can help avoid a headbite at times. On the other hand, Aliens are using it almost by reflex, some not even knowing they are. Since aliens don't have such a limit on their jumping abilities, they can use it to gain speed and avoid getting shot.

How to
After a jump has been initiated, and you are in midair, press and hold the jump button again, and you will jump again as soon as you hit the ground. Repeat that for each jump.

Other uses
It is basically used in long hallways to gain speed.

However, Marauders can use the same technique for jumping off walls. It is almost the same with a difference that holding the button while being in contact with a wall is enough to activate the ability, it doesn't require additional button presses after the first.

Also, a Dragoon can use his pounce to gain the initial momentum, and then continue on by bunny hopping.

Another purpose of bunny hopping is that, at times, you can make a soft turn without losing your speed. A sharp turn is hard, but not impossible. The faster you go, the harder it is.