How to Add Up Game-Contract Bonus Points in Bridge
Bridge has five special contracts called game contracts: 3NT, 4♥, 4♠, 5♣, and 5♦. They all give you a trick score of at least 100 points. If you arrive at any of these game contracts and make them, bonus points await. Lots of them.
By far the most common game contract is 3NT. Because six assumed tricks are always added to any bid, you need to take nine tricks to make this contract. The other game contracts require 10 or 11 tricks: 4♥ and 4♠ require 10 tricks, and 5♣ and 5♦ need 11 tricks.
After making your game contract and seeing your trick score (refer to Table 20-1), here come the bonus points!
If you bid and make a game contract, you get either 300 or 500 bonus points. Why two different bonuses? The amount of the game bonus depends on whether you are not vulnerable or vulnerable. There is no mystery to being vulnerable. It means you score a bigger bonus for bidding and making a game contract, but you also incur a greater penalty if you don’t make the game or slam contract that you bid for.
Vulnerability is preordained when playing Chicago. In other words, everyone knows before the hand is dealt who is vulnerable and who is not, which makes the scoring easier.
The formula for scoring up any game contract is the trick score + 300 for bidding and making a not-vulnerable game or the trick score + 500 for bidding and making a vulnerable game.
Say you bid and make 3NT, not vulnerable. Your trick score is 100 points + 300 bonus points = 400 points. If you were vulnerable, your trick score would still be 100 points, but you’d add 500 bonus points, making 600 points total.
If you bid and make 4♥ or 4♠, not vulnerable, your trick score is 120 points + 300 bonus points = 420 points. Vulnerable, your trick score would be 120 points + 500 bonus points = 620 points.
If you bid and make 5♣ or 5♦, not vulnerable, your trick score is 100 points + 300 bonus points = 400 points. Vulnerable, your trick score would be 100 points + 500 bonus points = 600 points.