The Danger Card deck helps the players to shape the difficulty level of the game to their tastes. Any mission can be customized by simply replacing the standard Close-Encounter cards with the Danger variants making the game more challenging. In Galaxy Defenders, one Close Encounter card is drawn on each Alien turn. With the standard Close Encounter cards, if there are no matching aliens on the battlefield, the alien turn typically ends immediately. However, with the Close Encounter Danger Variant Cards, if there are no matching aliens on the map [as indicated by the Effects section of the card], new aliens are teleported onto the map.