Once allies have committed, the offense and defense both select encounter cards from their hands to place face-down, then reveal them. If both cards are Attack cards, the total of the attack value and number of allied ships are added for both sides, and the side with the larger value wins with the defending player winning in case of ties. All players involved in the encounter may play Reinforcement cards from their hands to add numerical bonuses to each side's forces. If the offense's side wins, the defense's colony is lost and all ships on the defense's side are sent to the warp, while the offense and their allies land their ships on that planet, establishing new colonies on it. If the defense's side wins, all ships on the offense's side are sent to the warp, and defensive allies gain a reward of either a ship from the warp or a new card from the deck for each ship risked. If both players use Negotiate cards, they have one minute to make a deal, such as exchanging colonies or cards from their hands, while all allies are sent back to their owners' colonies (allies get nothing in this situation). If a deal can't be made, both players lose three ships each as a penalty. If one side plays a Negotiate card against an Attack card, they immediately lose, but they, though not their allies, get "compensation" from the victor by drawing cards from the victor's hand equal to the number of ships they lost in the battle.