The subject of the opera, very generally, is the destructive and isolating nature of gambling addiction.

Herman is an army officer who manipulates the naive Lisa, the granddaughter of a countess known as the Queen of Spades.

The countess knows the "secret of the three cards" and has revealed it to two men, but if she reveals it to a third, she will die.

Herman becomes obsessed with learning the secret, and it costs him his possessions, Lisa, and ultimately his own life.