The Overwatch Sniper is a soldier in the Combine Overwatch, trained in the use of the Overwatch Sniper Rifle. Snipers are encountered hiding in high, concealed areas where they can get a good field of view. They are never seen holding their rifle but the blue transparent sighting beam emitting from it is. They can be detected by the beam or by the sound of the rifle firing on another target. Gameplay wise, it succeeds the HECU Sniper featured in Half-Life.
Snipers are very accurate, and will fire ahead of any moving target so the pulse from the rifle hits them dead on. However, it is possible to confuse the sniper by running in one direction until he fires, then suddenly changing direction, then repeating the same process again until they reach cover. The round travels so much slower than other bullets that sidestepping the shot is quite easy at long range. However, snipers will take leading shots(shooting to the direction the target is supposed to go), they almost have a guaranteed hit, and will take you down in 1-2 shots without armor. They will also shoot breakable objects to limit the amount of cover the target can use.
Snipers seem to take the doctrine "shoot anything that moves" quite literally, shooting at any living creature (except allied Combine forces), such as birds, and even signs.
Snipers usually set up in well fortified 'nests', effectively invulnerable to ordinary gunfire. Explosives are a different matter, however, and if the player can get close enough, a hand grenade will blow the sniper out of his hole nicely. This can be easier said than done, however, because if the sniper spots the player before they're within range, which is often the case, they'll have to avoid his fire to get close enough.
Snipers will try to expose the player from cover if they're hiding behind light or breakable objects by shooting them. Even unbreakable objects such as barrels can be knocked some distance by the impact of the bullet.
Units leading from 01 and onwards will be able to follow a course, teaching them how to react and act with a sniper.
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