First create the baseball diamond by placing the 4 base cards on a table in the shape of a baseball diamond. Home plate on the bottom.
Decide which player will be at bat first. Divide the batter & pitch cards between the players. Also decide how many innings you will play, three is good for a first game.
Each player picks a card, and both place their cards face up on the table at the same time.
For example, if the pitcher plays a 6 and the batter plays a 2; add the numbers together (8) and then lookup the result from the outcome table card. In this case 8 means the batter has fouled the ball.
Players continue to play cards until their hand is empty. Then they can pick up all the played cards and start over. The play follows standard baseball rules. Fouls count as strikes, but you cannot be struck out on a foul ball. Three strikes mean the batter is Out. Three outs mean the players switch roles, the batter becomes the pitcher and the pitcher becomes the batter. After the 2nd player receives 3 outs the inning is over. .
If a player receives 4 balls, this means the batter has been walked, the batter now becomes a runner. Turn his card over and place him on first base. If a runner is already on 1st they move to 2nd (only one runner can be on a base, each runner may be advanced to the next base if necessary including home plate if there were 3 runners already on base).
A hit! If a batter hits the ball, turn over their card and put them on the appropriate base according to the outcome table.
Stealing Bases – if the player who is batting chooses they can attempt to steal a base. This means moving one of their runners to the next base. Just declare that you are stealing a base. Then do rock/paper/scissors to determine whether they advance or are Out.
A run is scored if a runner makes it all the way to Home Plate. Runners are added to the batter discard pile until all the batters have been played.
At the end of the last inning, whoever has the most runs wins the game. In the event of a tie, the players can choose to play extra innings until the tie is broken.