Each card has an image, name, text and arrows on the card. Only the text and arrows are meaningful while playing Tetra Master.
The text on the card is always four characters long, in the form of: 0P00. The first character is the card's attack power in hexadecimal notation. The second character is one of four letters to denote the attack type: P, M, X, or A. These stand for Physical, Magical, Flexible, and Assault type, respectively. The third character is the card's physical defense in hexadecimal notation. The fourth character is the card's magical defense in hexadecimal notation.
Hexadecimal notation uses 16 values instead of decimal's 10, namely 0–9 and then followed by A, B, C, D, E, and F. In addition, the game uses these hexadecimal values to indicate a range of 16, so 0 is actually a range from 0–15 and C is the range from 192–207. So when a card has a magic defense of C, it actually has a random defense value from 192 up to including 207.
Cards with a physical type attack the other card's physical defense. Cards with a magical type attack the other card's magical defense. Cards with a flexible type attack the other card's lowest defense type. Cards with an assault type attack the other card's lowest value on the card (that includes the attack power value).
The arrows on the cards show in which direction the card can attack. If two arrows of cards directly point to each other a battle will ensue. If the arrow points to a side of a card where there is no arrow pointing back, the battle will automatically be won.