Fundamentals of Modern Bidding

Open the bidding with 13+ points. Respond with 6+ points. Opening 1♥ or 1♠ (Majors) promises at least five cards. Opening 1♣ or 1♦ (Minors) may not have five cards in the suit. Open the longer minor suit. This bidding system is Standard 5-Card Majors. 
The ranks of the suits
No Trumps
Spades ♠
Hearts ♥
Diamonds ♦
Clubs ♣

Open 1NT as often as possible to show a balanced hand, 15 – 17 points. Shape = 4.3.3.3, 4.4.3.2,and 5.3.3.2. As responder, bid your long suit (6+ cards). Partner will have at least 2 cards there.

Balanced Responses 
0 – 7 pts, pass
8 – 9 pts, raise to 2NT (1NT p 2NT)
10+pts, raise to 3NT (1NT p 3NT)

Unbalanced Responses
0 – 7 pts, bid 2 of a long suit (1NT p 2♦/♥/♠)
8 – 9 pts, bid 2NT (1NT p 2NT)
10+ pts, jump to game with 6+ cards, or to 3 of your suit with 5 (1NT p 4 ♥/♠ OR 1NT p 3 ♥/♠)
Scoring: Bidding game gives an extra 300 or 500 points depending on “vulnerability”. You need 25+ points to bid to game. Game Contracts: 3NT, 4 ♠ or 4 ♥, 5 ♦or 5 ♣

With a fit (3 + cards)
6-9 Raise to 2 (1♠ P 2♠)
10-12 Raise to 3(1♠ P 3♠)
13+ Raise to game (1♠ P 4♠)

Value shortage points (in other suits), as these improve trumping power.
For each doubleton (2 cards) add 1 point; singleton (1 card) add 3; and void (no cards) add 5.
A new suit by responder is forcing, (opener must bid again), as the partnership is trying to find a fit.
Sometimes responder has 6 – 9 points, and none of the above. Respond 1NT, a limit bid.

Suummary: Minimum Hands
6-9 Raise to 2 of suit opened (1♠ P 2♠) with 3+ card fit
6+ Bid new suit at 1-level (1♦ P 1♥) with own suit
6-9 Bid 1NT(1♠ P 1NT) with no fit

Medium Hands
10-12 Raise to 3 of suit (1♠ P 3♠) with 4 card fit
10+ Bid new suit at 2-level (1♠ P 2♣)

Maximum Hands
13+ Raise to game (1(spades; P 4♠) with a fit
13+ 2/3NT (1♠ P 2/3NT) balanced hand
13+ Bid own suit at 2 level. (1♠ P 2(♣/♦/♥)

At their second turn, opener now shows precise shape and strength

• minimum hand = 13–15 points
• medium hand = 16–18 points
• maximum hand = 19–20 points

Opener also defines shape
1. Single-suited (six+ cards in one suit)
2. Two-suited (five+ cards in one suit, four+ in another)
3. A balanced hand
4. A hand with support for responder’s first bid suit
• With minimum values, bid as cheaply as possible. Pass if responder invites
• With medium values, jump a level
• With maximum values, go straight to game

• Consider the combined points. If fewer than 25, play a partscore.

25+ points, go to game

Responder’s point ranges are:
Minimum: 6 – 9 points
Medium: 10 – 12 points
Maximum: 13+ points