Gwent has several different in-game currencies to be used for purchasing different in-game items. Currently, these currencies are ore (used for purchasing kegs or Arena entries), scrap (used for crafting new cards), meteorite powder (used for transmuting normal cards into animated versions called Premiums as well purchasing other cosmetics from the shop), and reward points (used in the Reward Book to obtain ore, scrap, meteorite powder, kegs, factions kegs, leader skins, and to unlock leaders).
Ore can be earned in various ways by playing the game normally. Scrap is primarily earned through milling cards. Meteorite powder can be purchased in the in-game shop or earned by milling of premium cards. Reward points are earned by completing in-game achievements called Contracts or as level-up and end of season rewards.