In reaction and race card game Pick-a-Dog players need to grab cards from the grid and stacking them in hand. The card grabbed must be identical to the top card in hand or differ from that top card in only one way. Thus, as you grab cards, the attributes of that top card will keep changing, forcing you to look for matches in new ways. Once a player thinks he can't grab any more cards, he yells "Stop!". The round ends, and all players check their card stacks. If someone made a mistake when grabbing cards, that player keeps none of the cards gathered that round. If the player who stopped the round made no mistakes, he earns an extra card (two cards when playing with 6-8). If, however, he stopped the round when he could have collected more cards, then he loses all the cards he's collected during this round. Whoever has collected the most cards when the game ends wins!
Video review: YOUTUBE