Tetra Master was an online collectible card game available through the PlayOnline service on PlayStation 2 and Microsoft Windows. The game was based on the card minigame from Final Fantasy IX. It featured 250 cards from Final Fantasy IX and Final Fantasy X. The service required an additional monthly fee of ‎¥100 JPY (‎¥105 JPY with tax), €1 EURO, £0.70 GBP, or $1 USD on top of the existing PlayOnline subscription. The online service was discontinued on December 31, 2010, rendering the game unplayable due to its lack of an offline mode. In the original Japanese version of Final Fantasy IX, the minigame was called "Quad Mist," with the name written in English text on the game board. The English localization introduced the name "Tetra Master," which was subsequently used in both Japanese and English versions.