The Gold is used to use obtain cards from Card Trader. Players can earn Gold by completing missions, exchanging cards, and winning duels.
Completing stage and weekly missions is the most effective way to earn gold. Players will finish easy missions at fast.
Cards can be converted into gold. Players can gain more amount of coins by converting rarer cards.
Gold is also reward for winning a duel, but it is not the efficient way. Gold does not appear as reward ever time, and the amount is less.
Gold is currently only used to trade with the Card Trader. The required amount of gold varies based on the rarity of cards.