Stop it! is a fast action dexterity card game where all players grab coloured cards from five piles as quickly as they can. The deck is made up of 135 cards in 7 different coloured suits. Each suit is made up of 17 colour cards and 2 coloured Stop cards. The remaining 2 cards are Superstop cards.

The basic flow of the game is that everyone grabs cards with one hand and puts it into their other hand until a stop card surfaces and someone yells "Stop " for the colour of the stop card. Any players in the process of picking up a card can add this card to their pile.

Then, each player counts the number of cards of that colour and the player with the fewest (or tied for the fewest) cards in that colour receives a –1 card from the initial stock of 15 –1 cards. Additionally, if any player has cards out of order in their hand (not grouped by colour), they receive an additional –1. The player who called the Stop then calls Go and the mayhem continues. Superstops cause the play to be stopped and the total number of cards to be compared, with the person with the fewest cards receiving a –1. The game ends immediately when the last –1 card is given out, and the winner is the player with the fewest –1 cards.