Cards of Ethernity (CoE) is a digital collectible competitive card play-and-earn game built in the dark fantasy universe known as Aether. CoE was designed to be a quick, fun, and accessible game, but also offers significant depth, strategy and complexity for more serious players.

The game currently features 150 collectible cards, and players can build and explore their card collections through an in-game collection browser. Players can gain new cards by purchasing drop packs, using in-game currency, or by crafting new cards. Players can choose to play various different Adventurers complete with its own unique creatures, spells, and relics. Each Adventurer has its own unique trick, which tends to epitomize its character and playstyle.