Gameplay in Star Wars TCG involves playing location cards that can be converted to either the light or dark side, in order to “force drain” the opponent. Force, represented by decks, is the resource spent to play everything, but once exhausted, cards used to channel Force are removed from play. When the opponent is parried, you win.
Winning lightsaber duels, fighting opponent characters, or reaching special game conditions can speed up the force drain rate, and this is what made the Star Wars TCG so successful.