Gamma Base was the designation given to a Rebel installation situated on the planet of Hoth.
A small contingent of Rebels occupied the base around the time that the Battle of Tatooine occurred. Following the destruction of Anchorhead Base during that conflict in the year 0 BBY, Rookie One relocated to this location.
Imperial Viper probe droids discovered its location, leading to an attack by Imperial forces, including All Terrain Armored Transports. Rookie One successfully targeted and downed one walker utilizing his snowspeeder, subsequently reaching the hangar and escaping alongside the remaining Rebel fleet as Stormtroopers and Snowtroopers overwhelmed the base.
Gamma Base was conceived for the 1993 LucasArts video game titled Star Wars: Rebel Assault. The game itself does not specify the planet where Gamma Base is situated; however, both the instruction manual accompanying the Sega CD version and the packaging for the PC version identify the icy world as Hoth.