Like Final Fantasy VIII's Triple Triad, FF IX's Tetra Master involves two players taking turns placing cards onto a grid and trying to capture the other player's cards. This time, however, the grid is 4x4 (instead of 3x3), with anywhere from 0 to 7 spaces being randomly covered before the game begins.

   Every card can have up to eight arrows pointing in different directions; note that the arrows are not dependent on the picture on the card -- in other words, it's possible to have one Flan card with two arrows and another Flan card with three arrows pointing in completely different directions. These arrows determine what happens when one card is placed next to an enemy card.

• If the two adjacent sides / corners have no arrows, nothing happens.
• If the enemy card has an arrow, but the just-played card does not, nothing happens.
• If a card is placed down so that one of its arrows is pointing at an non-arrowed side / corner of an enemy card, the enemy card is captured.
• If a card is placed down so that one of its arrows is pointing at an arrowed side / corner of an enemy card, the two cards "battle." The card that comes .

   Each card has four letters or numbers on it. The first is its attack power (in hexademical), the second is its method of attack (P is Physical, M is Magic, and X is Auto, meaning the card uses whichever works best), the third is its physical defense, and the fourth is its magical defense. When two card battles, their attack powers are compared; whichever card has the higher attack power gets to determine the attack type. (A tie goes to the just-placed card.) Then, whichever card has the lower defense for that attack type (physical or magic) loses.

   In addition, when an enemy card is captured via a "battle," it can then capture any already-placed cards to which its arrows point -- a combo attack.

   The game ends when all 10 cards have been placed; whoever controls the most cards wins. (It's possible to have a draw.) The winner then gets to pick one of his/her opponent's cards to take; note that you can only select cards that were under your control at the end of the game. However, if you managed to end up with all 10 cards under your control at the end of the game, you score a "Perfect" and get to take all of your opponent's cards.

   You may never carry more than 100 cards; if you end up with more than 100 cards after a game, you have to throw away cards of your choice until you have 100. (If you want to get all the cards, this means you have to have exactly one of each card.)

   The rules in Tetra Master remain consistent no matter where you play; unlike Triple Triad, there are no varying gameplay or trading rules.