Tales of Ember is a free-to-play digital collectible card game. Decks are thirty cards and singleton, so no card appears twice. Fifteen heroes are spread across five prisms, ten of them combining two prisms, which determines what a player can build before the first card is played. Modes include a weekly ranked ladder that resets on Sunday, a curated draft format, campaign puzzles and community tournaments. The game runs on Windows, macOS, Linux, Android and iOS with cross-play on a single account. Its rules engine and card statistics derive from OpenSky, the open-source release of the code behind the discontinued game Skyweaver, re-implemented on a different engine.