There are three main currencies in the game: Gold, Gems, and Buddy Points. Gold is the most basic and easiest to obtain followed by Buddy Points and then Gems.
It can be obtained from chests as well as completing levels in Story Mode or Adventures. The harder the level the more gold obtained generally. Gold can also be obtained from selling Dynamons, with rarer Dynamons yielding more. On weekends in Adventures there is a special event called Weekend Warriors, where a level called Coin Crusade is available to play where a large amount of gold is obtained from completing it.
Gold is used to pay for levelling up and evolving Dynamons. The higher the rarity of the Dynamon the more expensive the cost becomes with of evolving. The more Dynamons being fused together to level up on, raises the cost.
It is possible to obtain Gems rarely through some Story Mode levels and through the in-game store in exchange for real money.
Gems can be used to Rare Summon and Special Summon Dynamons of 3-5 rarity. It can also be used to upgrade the inventory space and refill the stamina from the in-game store. Gems can be used to unlock chests before their time has run out instead of an Ad.
Obtaining Buddy Points
These are obtained from Chests as well as playing levels in Adventures or Story Mode using a buddy. You gain more Buddy Points using a previously added Friend (10 points) rather than a new buddy (5 points).
Buddy Point Usage
They are only used for Buddy Summons which can give the player a random Dynamon of 1-6 star rarity. These can include Evolution Material or Level-Up Material which is hard to come by or catch in the wild.