A collectible card game where the players combat each other with mathematical equations.
Each card has a digit or operation, its point value, ability, illustration of the being it represents, and attributes that influence its strengths and vulnerabilities. Blue-backed cards are the digits 2-9, and orange-backed cards are the digits 0 and 1, and arithmetic operators (+-x÷).
Each player starts with a deck of 50+ cards with no more than 3 copies of any card; it's recommended they have at least 20 orange cards and 30 blue cards. Players shuffle the blue and orange decks separately, play 5 blue cards and 3 orange cards to the table, keeping 3 orange cards in their hand.
The roles of Effector and Protector alternate each round. The players lay out an equation from their cards, Protector first, and then attack the opponent's cards with their cards, Effector first. Then each player adds the points of their surviving cards to their total. The first player to 50 points wins.
The setting for the game is the World of Aura, and each card represents (in addition to a letter) a character from one of Aura's four kingdom/continents:
Terra: Earth-like creatures
Dragonia: Dragons
Hydra: Sea creatures
Industria: Robots