A Sniper-spotter team (also referred to as scout-sniper team) consists of two people, one to spot the targets and one to use the Sniper Rifle.
Both the sniper and spotter are often fully qualified as a sniper, but have different duties. These duties are often rotated for various reasons, such as to reduce eye fatigue of the spotter during observation and to reduce arm fatigue of the sniper.
The sniper takes the advice and commands of the spotter, changing and firing on targets. The sniper is very vulnerable to attack when sniping, which is why snipers will have their spotters providing security. The sniper, of which there is only one, is armed with a long-ranged weapon.
The spotter detects, observes, and assigns targets and watches for the results of the shot. Using a spotting scope, they will also read the wind by using physical indicators and the mirage caused by the heat on the ground. Also, in conjunction with the shooter, the spotter will accurately make calculations for distance, angle shooting (slant range), mil dot related calculations, correction for atmospheric conditions, and leads for moving targets. The spotter is also usually tasked to ensure proper communication with adjacent units, adjusting how the indirect fire and close air support will work for the team.
The spotter is also charged with team security. Because of this, they are usually armed with medium to close-ranged weapons.
As a Corporal, Avery Johnson worked with an unnamed Marine, potentially Nolan Byrne, during an operation to assassinate Jerald Mulkey Ander on the planet Harvest in 2502. Johnson was the sniper, while the other Marine was the spotter.
While Spartan-II Linda preferred to work alone, the other SPARTANs always had a spotter when sniping. Fred was the best spotter, in addition to his other talents. There was also a scout Sniper-spotter team in the Battle of Mombasa that informed Johnson's Pelicans that the area was "hot with Covenant".