Remember that gauss gun I told you about the other day? It turns out that the gun can also be used to convince people that you're cheating. If you're into that kind of thing.

Okay, so, first, get a gauss gun.

Then, find a wall, preferably one that one of your opponents has just run behind. Then, charge up the gun and let fly a shot. If you've charged it fully, the shot will bore right through the wall, and right through any poor schmuck who's using the wall for cover.

It's kind of tough to aim this way, you know, since the wall's opaque and all. But it's really satisfying if you can do it with any kind of frequency.

In the original Half-Life, you had all kinds of weird guns with all kinds of awesome abilities. One of them is the Tau Cannon, or the Gauss Gun.

Now, your normal jumps are... well... normal for a wiry scientist in average physical condition.

But, hold down the alternate fire button (usually the right-mouse button) for a few seconds to build up a charge, then aim it straight down and let go. The kickback will launch you into the air. How high? About this high:

High enough that you'll injure yourself when you land.

Awesome.