A standard deck of 52 cards is shuffled and placed face down. The player will click two cards to flip them over. If the cards have the same face they are removed. Other variants require matching both the face and the color. If the cards do not match they are turned face down again and the player will turn over to more cards.

Play will continuue until all cards have been removed.

Additional info about Concentration

This version is designed as solitaire and the goal is to complete in the shortest time.