Thirty-one is a simple card game also known as Scat and Blitz. You can play 31 with two to 10 players and a standard deck of cards. The game is simple enough for younger children and requires both skill and luck as players try to balance getting a good hand and catching others with bad hands.
The goal of 31 is to collect as many points in one suit as you can in your three-card hand. Each numerical card is worth its face value, with face cards worth 10 points and aces worth 11. The top score any player can have is 31--an ace and two 10-point cards, all of the same suit--hence the name of the game.
Each player is dealt three cards and is given three pennies for scoring. The rest of the cards are placed in the center. The top card is turned face-up and set next to the deck. The player to the left of the dealer goes first and can draw the face-up card or the top card from the deck. He then must discard one card to the face-up pile next to the deck.
If a player thinks her hand's score is not the lowest in the group, she can end the round on her turn by "knocking" instead of drawing and discarding. Then every other player gets one last turn to draw and discard.
The exception to this rule is that if a player draws and gets exactly 31 points. He can reveal his hand immediately and end the round. In this case, the other players do not take a last turn.
When drawing and discarding, players should balance keeping cards with high values and keeping cards of the same suit. Players also should be attentive to how long the round has been going on. A hand with a score of 15 is probably not the lowest at the beginning of the round, but it might be after players have had a few opportunities to draw and discard.
After a player has knocked and other players have taken their last turns, each player reveals how many points in a single suit he has. The player with the lowest total loses one penny. If two or more players tie for lowest, they each lose a penny. If the player who knocked has the lowest score, he loses two pennies. If the round ended with a player getting a hand of 31 points, then all other players lose a penny.
Players with no pennies can continue playing, but when if lose again, they are out of the game. The last player still in wins.
If pennies are not available for scoring, players can keep score mentally. One such way to score without using pennies is through "riding the bus." In this method, players start at the back of the bus (equivalent to three pennies), move to the middle of the bus (two pennies), the front of the bus (one penny), on the stairs (no pennies) and off the bus (in a situation when a penny would be needed and none are available).