Boardgamegeek https://boardgamegeek.com/boardgameexpansion/181690/star-wars-imperial-assault-echo-base-troopers-ally
English - Rebel Troopers fight across the galaxy, but the troopers stationed at Echo Base were specially trained to deal with the extreme environment that awaited them there. This specialized training can make the difference between victory and defeat in a game of Imperial Assault.