Geonosian Droid Foundry

When this card is in play, all players may play as
many units with “B1” in their name during their
turn as they want. (Energy Costs for
summoned units must still be paid).

"As I made my way through the catacombs of Geonosis, I heard the clanking of machinery growing louder. Once I stumbled through the entrance to the droid foundry, I knew the 212th legion had no chance of taking control of Geonosis."