Players were able to purchase virtual cards and trade them with each other. Each set included up to 300 cards, with more sets being released every few months. Both former and current Galaxies subscribers received a single 58-card starter deck when they signed up; all active subscribers also received five free 15-card booster packs per month after that, with the option to purchase more available for all players.
A non-subscriber using the trial mode could sign up for at least a one-month subscription to Star Wars Galaxies. This allowed access to the complete gameplay modes and enabled trading with other players. Suspending the subscription afterwards made the account stop receiving free monthly packs, but full access to the game content remained.
The trading card game, along with Star Wars Galaxies MMORPG, was shut down on December 15th, 2011.
There were four archetypes in the game: Jedi, Rebel, Imperial and Sith. Each archetype had a unique avatar, which represented the player character. A deck could not contain any cards of a archetype different from the archetype of your avatar. The were however so-called generic cards, which did not belong to any archetype and could be included in any deck.
Other card types included units that could fight alongside your avatar; items, which could be used to give the player avatar various bonuses; tactics, which represented one-time surprise actions in combat; quests, which represented the missions the players undertook to advance in the game; and abilities, which were used to complete the quests.
Important game mechanics included cost, which had to be paid to play the card; power that was used to pay the cost; strength and defense, which were used to resolve the skirmishes; damage, which could be used to deal more damage to the enemy unit; health, which represented how much damage a unit or avatar could take before it was destroyed; and level of abilities, which could be used to complete quests.
Each player had four quests with level numbers of 2, 4, 5 and 6 aside from his main deck, and the quests with the level number of two were played automatically at the beginning of the game. At the beginning of his turn, if the player had an active ability in play, he could apply it to one of the quests to place tokens on it equal to the ability's level. Whichever player first placed a number of tokens equal to quest's level completed the quest and placed his quest with the next number in its place. The goal of the game was to complete four quests before your opponent; however, the game could also be won by destroying your opponent's avatar first. To prevent that, each player could deploy units to one of the quests (yours and your opponent's) that could both raid (attack) opponent's units and avatar and protect your avatar from being attacked.
The game provided multiple options of gameplay, in both single and multiplayer modes:
- / – a guide to all basic aspects of the game, which also allowed to play as a Jedi vs the Sith AI opponent using either starter or pre-constructed decks.
- – a practice match versus human opponent, using either Jedi or Imperial starter deck.
- – story-based matches with AI opponent, who had significantly improved decks. Every new set expanded Light side and Dark Side campaigns with 5 new scenarios for each campaign. Each scenario had 3 levels of difficulty, for completing scenario on each level players receive bonus reward cards.
- – allowed players to test their new decks versus AI opponents.
- – a basic game versus human opponent.
- – in this story-based game mode four players worked together, trying to defeat a single AI opponent with an overpowered deck. Each heroic encounter was based on a heroic encounter from Star Wars Galaxies.
- – required an entry fee to play, but offered prizes to the winners.
The game also featured Loot cards, which were special cards for rare items, such as the Muur Talisman, that were randomly found in booster packs. These could be redeemed for in-game items in Star Wars Galaxies. To start with, there were 26 such cards, with more available via special promotion actions.