Mastering the Rule of 20 in Bridge

Looking at your borderline hand with 10 or 11 High Card Points and wondering whether you should open the bidding is one of the most common decisions you'll make in bridge. If you pass, you might let your opponents steal the contract; if you bid, you risk getting too high.

Fortunately, you don't have to guess. The Rule of 20 is a simple guideline designed to help you confidently decide whether a light, shapely hand is worth opening.

To help you master this concept, we've built an Interactive Rule of 20 Practice Tool directly into this guide below. You can deal random hands to test your math skills instantly, or read on to break down the exact formula and expert nuances like the Rule of 22

How The Bridge Rule Of 20 Works With Examples

It's only supposed to be used for opening the bidding in first and second seats. In third seat players often open light anyway so there's no need for a special rule. In fourth seat there's no need to open light to disrupt opponents. They've both passed!

The Rule of 20 considers both high card points and distribution.

Count your high card points.

This is your basic high card point count. You don't add anything for length or shortage, you simply count 4 points for each ace, three points for each king, 2 points for each queen and 1 point for each jack.

Add the length of your two longest suits.

Length is strength so two 5 card suits are better than two 4 card suits.

Open if the total comes to 20.

For example, if you have high card points and two 5 card suits your total comes to 20 and you have enought to open the bidding.


Rule of 20 Practice Dealer

Test random holdings to master light openings.


The Rule Of 20 In Action

Here's a hand from one of our daily free bridge games.

An Opening Hand With 10 High Card Points

South's points are the ♠A (4), ♠K (3) and K (3). That's 10 high card points. The two longest suits are spades (5) and hearts (5). That's 10 length points. 10 high card points + 10 length points = 20. 20 total points is enough to open.

Bridge Card Game
An opening hand

The Rule of 22: Taking The Rule Of 20 A Step Further

Not all points are equal! The rule of 22 takes into consideration 'quick tricks' as follows:

To use the rule of 22, start with the rule of 20, add your quick tricks and check if the total comes to 22.

An Opening Hand Using The Rule Of 20

South's points are the ♠A (4), ♠K (3) and K (3). That's 10 high card points. The two longest suits are spades (5) and hearts (5). That's 10 points length. The ♠A and ♠K is 2 quick tricks. The K is .5 quick tricks. That's 2.5 quick tricks. 22.5 is enough to open.

Bridge Card Game
Open 1♠

Singleton Kings Are No Good

South has 10 high card points. South has 10 length points. The ♠A and ♠Q is 1.5 quick tricks. The K is 0! Singleton Kings don't count. That's 1.5 quick total. 21.5 total points is not enough when using the rule of 22.

Bridge Card Game
Open 1♠

Honours In Short Suits

Honours in short suits don't pull their weight. They don't help us set up tricks in our long suit and, especially in the case of singletons, they often don't win tricks at all.

Weak Suit

The diamond honours aren't well placed. They're not helping to establish your long suits. If you open 1♠ and partner responds 2 what will you bid? Maybe it's still worth opning this hand but things could go wrong.

Bridge Card Game
An opening hand

Frequently Asked Questions

What is the Rule of 20 in bridge?

The Rule of 20 is a bidding guideline used to determine if a light hand with fewer than 12 High Card Points (HCP) is worth opening. If the sum of your total HCP and the length of your two longest suits equals 20 or more, the hand is considered strong enough to open.

Does the Rule of 20 apply in the 3rd or 4th seat?

No, the Rule of 20 is primarily designed for 1st and 2nd seat opening decisions. In the 3rd seat, players often open even lighter to disrupt opponents. In the 4th seat, players typically use the Rule of 15 instead.

I favor light opening bids, when you're my age you're never sure they're going to get back to you in time.
Oswald Jacoby