In the Doctor's many adventures through time and space, he has encountered monsters and aliens, and he has made friends on Earth and on many worlds. The 180-card Extreme series feature cards with the Doctor, his allies, his gadgets, the villains, the monsters, and his mind-blowing adventures. Look out for Rare and Super Rare 3-D cards! Rare cards contain unique codes that will unlock power-ups in the games. If you are lucky enough to find a Super Rare 3-D card, enter the card code on the Monster Invasion website, hold up the marker to your webcam, and you will see the image come to life on your hand! Doctor Who: Monster Invasion Extreme Booster Packs each contains 9 cards with at least 7 common cards and 1 rare.