Snipers are excellent in XCOM: Enemy Unkown. Their accuracy actually increases the further they are from their target (within reason), putting them out of danger for most battles. Their rifles have high damage output and high critical chance, though unless you unlock a certain ability, Snipers cannot fire their rifles and move in the same turn. As such, it is recommended that you equip this class with the best pistol you can get your hands on so that your unit will always have an offensive option no matter the circumstance.
Either Colonel ability for the Sniper class makes turns this unit into a death machine. If positioned correctly, a Sniper can turn the tide of an entire battle in one move.
Unfortunately, not all levels are suitable for a Sniper class. Sometimes they’ll fall behind the group, too, due to the aforementioned movement restriction. So as awesome as we found them to be, we only had one Sniper in our squad.
Headshot: Fire a shot with +30% critical chance and extra damage on critical hits, based on the tech level of the sniper rifle. 2 turn cooldown.
Corporal Abilities (choose one)
Snap Shot: Removes the sniper rifle’s restriction on firing and Overwatch after moving. Any shots taken suffer a -20 Aim penalty.
Squadsight: Allows firing at targets in any ally’s sight radius.
Sergeant Abilities (choose one)
Gunslinger: Confers 2 bonus damage with pistols.
Damn Good Ground: Confers +10 Aim and +10 Defense against enemies at lower elevation, in addition to the usual elevation bonuses.
Lieutenant Abilities (choose one)
Disabling Shot: Allows the Sniper to fire a shot that causes the target’s main weapon to malfunction. The target may use Reload to fix the weapon. The shot cannot inflict a critical hit. 2 turn cooldown.
Battle Scanner: Scanning device that, when thrown, creates a new source of vision for 2 turns. Can only be used 2 times per battle.
Captain Abilities (choose one)
Executioner: Confers +10 Aim against targets with less than 50% health.
Opportunist: Eliminates the Aim penalty on reaction shots, and allows reaction shots to cause critical hits.
Low Profile: Makes partial cover count as full.
Colonel Abilities (choose one)
In The Zone: Killing a flanked or uncovered target with the sniper rifle does not cost an action.
Double Tap: Allows both actions to be used for Standard Shot, Headshot, or Disabling Shot, provided no moves were made. 1 turn cooldown.