Play Bridge Online
view all bridge lessons

Bidding System

Opening 1♣, 1, 1, 1♠

Opening the bidding with 1 of a suit shows 12 or more points.

In some bidding systems an opening bid of 1 or 1♠ needs to be a 5 card suit but an opening of 1♣ or 1 only needs to be a 3 card suit. That style of bidding is called '5-card majors'.

In other bidding systems any opening bid of 1 of a suit only needs to be a 4 card suit. That style of bidding is known as '4 card majors'

Responding to 1♣, 1, 1, 1♠

The opener's partner is called the responder. Responder only needs 6 points to bid after an opening bid of 1♣, 1, 1, 1♠

Opener's Rebids

A reverse means that partner has to bid to the 3 level in order to return to opener's first suit. A reverse shows a strong hand with the first bid suit always being longer than the second.

Opening 1NT

An opening bid of 1NT shows a balanced hand which means no singleton or void and no 6 card suit.

Some players open 1NT with 15-17 points. That's known as a strong notrump.

Some players open 1NT with 12-14 points. That's known as a weak notrump.

The strong NT is normally used by those playing the Standard bidding system. Acol players normally use the weak 1NT

2♣ is Stayman after a 1NT opening as is 3♣ after a 2NT opening and after the bidding sequence 2♣ - 2 - 2NT.

You can choose to play transfers. Check your bidding system. If you have selected transfers then they'll work in the same situations as Stayman - after a 1NT opening, after a 2NT opening and after the bidding sequence 2♣ - 2 - 2NT.

The Sky Bridge Club computer does not play Stayman or transfers after a 1NT overcall.

Stayman and transfers are off after any bid or double by the overcaller

Opening 2♣

An opening bid of 2♣ shows a strong hand. It doesn't say anything about your holding in clubs.

Opening 2 2 2♠

2 2 and 2♠ opening bids are weak showing a good 6 card suit and 6-10 points*

* You can play strong 2 bids if you prefer but make sure to change your bidding settings.

Suit quality is important. A good rule of thumb is that you should have 2 of the top 4 honours. Intermediate cards are also important. KQ10975 is better than KQ5432. Having opened a weak 2, you should not bid again unless partner makes a forcing bid. Partner has enough information to know what to do.

Opening 2NT

20-22 balanced

3♣ is Stayman after a 2NT opening.

If you have transfers selected in your bidding system then 3 is a transfer to hearts, 3 is a transfer to spades and 3♠ is minor suit Stayman

Stayman and transfers are off after any bid or double by the overcaller

Opening 3♣ 3 3 3♠

Preempts. 7 card suit, less than an opening hand.

Opening at the 4 and 5 level

Preempts with an 8 card suit.

Slam Bidding Conventions

Quantitative 4NT

After partner's NT bid, a raise to 4NT is invitational, asking partner to bid 6NT or pass. It works in the same way that 1NT - 2NT invites partner to 3NT only this time you're interested in bidding slam rather than bidding game.


The Blackwood convention, 4NT asking for aces, is useful for slam bidding when you're likely to end up in a suit contract. You'll typically have good shape to use Blackwood but with fewer than 33 points you might be missing two aces.

4NT asking for aces
  • 5♣ = 0 Ace or 4 Aces
  • 5 = 1 Ace
  • 5 = 2 Aces
  • 5♠ = 3 Aces


The Gerber 4♣ convention is used to ask for aces after a 1NT or 2NT bid from partner.

Asking for aces - Gerber 4♣ 4NT asking for aces
  • 4 = 0 ace or 4 aces
  • 4 = 1 ace
  • 4♠ = 2 aces
  • 4NT = 3 aces

Competitive Bidding

Simple overcall

An overcall is a bid made after the opposition have already opened the bidding. Whereas an opening bid can show a 3, 4 or 5 card suit depending on your bidding system, an overcall is always a 5 card suit.

Unlike an opening bid, you don't need to have 12 points for a simple overcall. A good 5-card suit is the key and good rule of thumb is two of the top four honours in the suit.


A double in bridge bidding can be either a takeout double, used to ask partner to bid, or a penalty double, used when a player thinks the opposition won't make their contract.

  • Doubles of low level suit contracts are takeout.
  • Doubles of high contracts and notrump bids are penalties.

Takeout Double

  • 12+ HCP
  • at least 3 cards in the unbid suits
  • shortage in the opener's suit
  • asks partner to choose the trump suit

Penalty Double

A double saying that you do not expect your opponents to make their contract is called a penalty double. It increases your score if the contract fails and also increases their score if the contract makes.

Doubles of notrump bids are almost always penalties. If your side has the majority of the points then doubling their 1NT contract can be more profitable than playing the hand in a contract your way.

Negative Double

A negative double is the name given to a double made by the responder. It shows support for the unbid suits and a hand where you don't have a natural bid to make. It means that you can take part in the auction safely even with quite a weak hand.

  • 1-level = 6-9 HCP
  • 2-level = 8-11 HCP

Unusual 2NT

A jump overcall of 2NT shows 5-5 in the two lowest unbid suits.

Michaels Cue Bids

  • 1♣ - 2♣ = 5 hearts and 5 spades
  • 1 - 2 = 5 hearts and 5 spades
  • 1 - 2 = 5 spades and 5 of a minor
  • 1♠ - 2♠ = 5 hearts and 5 of a minor
Between Hands
Newsletter for bridge players.
Free to your inbox every week.