FPSers around the globe sigh dreamily at the site of it. Mud sloggers everywhere cringe in fear at the sound of it. Craniums near and far run and hide at its very mention. Yes, it's the sniper rifle - and what a sniper rifle it is.
As in most cases, the sniper rifle isn't always the answer. If there's some joker a half-meter away, waving a shotgun and swinging melees, then you'd have to be stupid (or very, very good) to use the sniper rifle. However, when you're a football field distant... then it's your dream come true.
The sniper rifle comes equipped with several features to make your life easier. It has three levels of zoom: the normal, unzoomed view, a 2x view for medium-ranges and for acquisition, and a 10x high-focus aspect for long-range tapping. Use the 2x to find a target, then (without moving your aim) zoom to the 10x to bring them down. What else is fun? Well, while zoomed, you'll have the helpful advantage of an optional night-vision mode for use in nighttime missions. It's surprisingly nice, especially when a light would make you stand out like hair on Bruce Willis.
Very likely the most dangerous projectile weapon in the game, the sniper rifle packs an enormous punch. Two or three hits to the body is enough to drop anybody, and a single headshot will bring down anybody who has a head. This is a good thing, since you only have a four-round magazine.
One useful side bonus is that the sniper rifle is a very good anti-vehicle weapon. While it won't do much to actual vehicles, all you need to do is zoom in close and blast out the driver, and the threat is removed. A great multiplayer deterrent.
It's not all well and dandy, however. One major disadvantage of the sniper rifle is that is will give away your position. Unlike some FPSs, where if you have a nice spot you can sit down and slag an entire army, in Halo the sniper rifle has one crippling drawback; it leaves contrails, long, foggy gray lines in the air, whenever you fire. If you don't kill your target the first time, he's likely to come after you, and if there's more than one, than you better be quick at the trigger and fast at the legs.
Ammo for this stuff is like mutated hen's teeth; nearly impossible to find, and irritatingly short-lived. Hoard it like they're going out of stock. Use head shots to make it count, and don't squeeze unless you've checked twice that there's somebody under your crosshairs.
Melee only as a very, very last resort - as in, when you've already gone through all your other last resorts and there's still an enemy on you. As if to balance out the sniper rifle's long range dominance, the melee speed is so slow you can actually dodge it.
Pros: Nearly infinite range and accuracy, extremely high damage with possibility of instant kills, numerous different optical configurations.
Cons: Reveals position, ammo hard to find and quick to go, melee speed perverted, short range uses limited.
Usage: ... at long range only. Whittle down an army with it before going in with your other weapons. Drop pilots from planes and drivers from vehicles. Kill enemies before they can see you. But once you have, pull out your normal gun, and get to work - because no matter how you try, you can't get them all.
Furthermore, know that the Flood will walk through sniper fire like it's not there.