Alien Wars: Gravity promo

A promo (15 cards) distributed by the publisher at various conventions. Rules: A card can never recover another card neither can it be separated by more than half an inch from another card. During the game, if a card or a group of cards strays more than half an inch from the main group –for example, after a card is eliminated– scoot the marooned card or group within a half inch of the main group before continuing to play.