The fun and addictive card game are here! Zero Twenty One: 21 Points is an online puzzle game. The sum of control cards is kept between 0 and 21. Use addition and subtraction to control the sum within the required range. If you encounter difficulties, you can place a card in the empty space to the right of the sum. Before you click on the cards, you have to think of a strategy in advance, I believe you can pass the level! have fun!