Official in-game currency includes Gold (Mobacoin), Silver, Rally points, & ISO-8 Shards. Other forms of currency may include items or cards used by players in seek of a trade. It should be noted that the exchange of virtual items or virtual currency between players for "real world" money is against the "Terms of Use."
Gold (Mobacoin)
Mobacoin is purchased in the in-game Store via credit card, iTunes credit, or Android credit. Mobacoin can be used to purchase items such as Energy Packs, Power Packs, or Shield Barriers. It can also be used to purchase Ultimate Card Packs to boost your deck with more powerful cards.
Silver
Silver is most often gained by completing missions or through battle with other players. It is also possible to sell any card for silver. Silver is consumed in the process of boosting and fusing cards, and is also one method of donating to your alliance. Silver is an important aspect of the game, and a competitive player will spend it wisely.
Rally Points
Rally points are gained when either you Rally another player or another player Rallies you. The fastest way to gain rally points is to go through your Team Members and Rally each of them. It is possible to Rally any player when you visit their page. Rally points are used to buy Rally packs that include random Common, Uncommon, Rare, Special Rare, Super Special Rare, and Ultimate Rares.
ISO-8 Shards
ISO-8 Shards are gained as rewards from events, such as raids, training, or combat. For certain events, these items can also be shared with your alliance. These shards are only good during the events, and are exchanged for random items, silver, rally points, and exclusive cards.