If you don’t make your contract in bridge, you’re penalized when it comes to reckoning time at the end of the hand. Penalties consist of points you give to the other team for not taking enough tricks in the hand to make your contract. Welcome to the sad world of going set, going down, or failing. When you come up short on your contract, the missing tricks are called undertricks.

When you don’t make your contract, your opponents score points above the line according to the following scale:

• 50 points per trick if you’re not vulnerable

• 100 points per trick if you’re vulnerable

Note that the opponents’ status is irrelevant — your status determines the penalties that you concede.

As an example, pretend that you have just started the second rubber of a set game. You and your partner won big in the first rubber, and you get to carry over 720 points from the first rubber.

1. On the first hand of the second rubber, you go for broke and bid 3NT, trying for game.

No luck. You take only eight tricks. You go down one trick not vulnerable. For each nonvulnerable undertrick, you lose 50 points. Those 50 points go above the line on your opponent’s side. Had you gone down two tricks, they would have chalked up 100 points above the line. It doesn’t hurt too much if they score points above the line at 50 points a shot; it’s the points below the line that kill you.

Your new score sheet looks like this image:

2. In the next hand, your opponents bid 4♥ and take 11 tricks, scoring 120 points and an overtrick of 30 points, for 150 points total.

Now, because they made a game contract, your opponents are vulnerable. The new score looks like this image (lumped, of course, because a game contract has been made with an overtrick):

3. In the next hand, they try to put you away by bidding 4♥, a game contract.

This time your defense is razor-sharp, and they take only eight tricks. They have failed by two tricks, vulnerable. Vulnerable undertricks are worth 100 points a pop, so you get to put 200 points above the line on your side.

Now, the score looks like this image:

4. In the following hand, your opponents bid 3 and take ten tricks.

The noose is tightening. Your opponents are vulnerable with 60 on (that is, they have a 60 partial). Record your opponents’ overtrick of 20 points above the line on the score pad. Your new score sheet looks like this image:

5. In the next hand, you wind up in 4♥, taking 12 tricks making your game contract with two overtricks.

You record your score of 180 points (120 for your contract and 60 points for your overtricks) as shown in this image:

6. Finally, tragedy strikes when your opponents bid 3NT and take 11 tricks, which is the second game contract that they bid and make.

They score 100 points for their contract and 60 points for their overtricks. Your opponents have won the rubber and get a 500-point bonus because you’re vulnerable. Time to tally up, as shown in this image: