Home · Learn · Advanced · Module 1
Two Over One Game Force
Upgrade your Standard American to the 2/1 game force structure: the 2/1 response, the forcing 1NT, inverted minor raises, new minor forcing and fourth suit forcing.
Two over one game force (“2/1”) is the most popular way to play Standard American among strong players, in Australia and around the world. It keeps everything you already know about opening bids, and changes one idea: when responder bids a new suit at the two level, the partnership is committed to game.
That single agreement makes slam bidding much easier. Once you know you’re going to game, neither of you has to jump to show strength. You can bid slowly, describe your hands, and find out whether slam is possible.
By the end of this module you’ll be able to:
- Respond with a 2/1 bid and know what it promises.
- Use the forcing 1NT response to a major.
- Play inverted minor raises.
- Use new minor forcing and fourth suit forcing to find the right game.
1. The 2/1 response
After an opening bid of one of a suit, a new suit at the two level by an unpassed responder, with no interference, is game forcing.
| Opening | 2/1 game-forcing responses | Not 2/1 |
|---|---|---|
| 1♠ | 2♣, 2♦, 2♥ | 2♠ (a raise), 3♣ or higher (jump shifts) |
| 1♥ | 2♣, 2♦ | 1♠ (a one-level response), 2♥ (a raise) |
| 1♦ | 2♣ | 1♥, 1♠ (one-level responses) |
| 1♣ | (none: every new suit is at the one level) |
What a 2/1 response promises
- About 12+ points: enough for game opposite an opening bid.
- A real suit. 2♥ over 1♠ promises five or more hearts. 2♣ and 2♦ usually show four or more, though 2♣ is sometimes a balanced game force with only three clubs because there is nothing better to bid.
When it is not game forcing
- Responder has passed. A passed hand can’t have game values, so a two-level response is natural and not forcing (see Drury in Module 2).
- The opponents interfere. After 1♠ (2♦) 3♣, most pairs play the new suit as forcing for one round only. Agree this with your partner.
Example
Partner opens 1♠. You hold:
♠ A 5 ♥ K Q 10 8 4 ♦ K 6 3 ♣ 9 7 2You have 12 HCP and a good five-card heart suit. Respond 2♥. You don’t know yet whether you belong in 4♠, 4♥ or 3NT, but you know you belong in game, and so does partner.
2. Opener’s rebid and the principle of fast arrival
Once you’re in a game force, jumping to game shows the weakest hand. This is the principle of fast arrival: “I have nothing more to say.”
| Auction | Meaning |
|---|---|
| 1♠ – 2♥ – 4♥ | Heart support, minimum opening, no interest in slam |
| 1♠ – 2♥ – 3♥ | Heart support, and enough to be interested in slam. Forcing |
| 1♠ – 2♥ – 2♠ | The default rebid: often six spades, or a minimum with no better bid |
| 1♠ – 2♥ – 2NT | Balanced, with no heart support |
| 1♠ – 2♥ – 3♣ | Four or more clubs, natural |
The slow bid is the strong bid. When partner raises slowly, look at your hand again and think about slam.
3. The forcing 1NT response
If a two-level response promises game values, how do you show a hand with 10 or 11 points and no fit? The answer is the forcing 1NT.
After 1♥ or 1♠, a 1NT response by an unpassed hand is forcing for one round. It shows about 6–12 points and covers several hand types:
- An ordinary weak hand with no fit.
- A hand with a long suit that isn’t strong enough for a 2/1 response.
- A three-card limit raise (about 10–12 points with three-card support).
Opener must bid again. With a balanced minimum, opener bids two of a three-card minor (2♣ with three cards in each minor) because there is no other sensible rebid.
| Opener’s rebid after 1♠ – 1NT | Meaning |
|---|---|
| 2♣ / 2♦ | Three or more cards in the suit; could be a balanced minimum |
| 2♥ | Four or more hearts, minimum |
| 2♠ | Six or more spades, minimum |
| 2NT | 18–19 balanced (too strong for a 1NT opening) |
| 3♠ | Six or more spades, invitational |
| 3♣ / 3♦ | A jump shift: game forcing |
Responder’s second bid
| Auction | Meaning |
|---|---|
| 1♠ – 1NT – 2♦ – 2♠ | Preference with two spades, weak |
| 1♠ – 1NT – 2♦ – 3♠ | A three-card limit raise, about 10–12 points |
| 1♠ – 1NT – 2♣ – 2♥ | A long heart suit and a weak hand. Not forcing |
| 1♠ – 1NT – 2♣ – 2NT | About 11–12 balanced, invitational |
Example
Partner opens 1♠. You hold:
♠ K 9 4 ♥ A 7 5 ♦ Q 8 6 3 2 ♣ 6 2You have 9 HCP plus a doubleton: about a limit raise with three spades. Bid 1NT (forcing) and then jump to 3♠ at your next turn. That tells partner you have three-card support and invitational values, which is exactly what partner needs to know.
Alert it. Under the ABF Alerting Regulations a forcing 1NT response is alertable. Partner says “Alert” and puts out the alert card when you bid it.
4. Inverted minor raises
In standard methods, 1♦ – 2♦ is weak and 1♦ – 3♦ is invitational. Inverted minors turn this round:
| Auction | Inverted meaning |
|---|---|
| 1♦ – 2♦ | Forcing for one round: about 10+ points, good diamond support (usually five or more cards, though some pairs allow four), and no four-card major |
| 1♦ – 3♦ | Pre-emptive: about 5–9 points with good support |
The strong raise is kept low so that you have room to explore. After 1♦ – 2♦, opener shows the shape of the hand:
- 2NT: a balanced minimum (about 12–14).
- 2♥ or 2♠: a stopper in that suit, looking for 3NT.
- 3♦: a minimum with no interest in 3NT.
Inverted minors are alertable in ABF events: both the strong single raise and the weak jump raise.
5. New minor forcing
After 1♣ – 1♥ – 1NT (or a similar auction where opener rebids 1NT), responder often wants to know whether opener has three-card support for responder’s major, or four cards in the other major.
New minor forcing uses the unbid minor as an artificial question:
1♣ – 1♥ – 1NT – 2♦: “I have at least invitational values. Tell me more about the majors.”
| Opener’s reply | Meaning |
|---|---|
| 2♥ | Three-card heart support |
| 2♠ | Four spades, no three-card heart support |
| 2NT | Neither, minimum |
| 3NT | Neither, maximum |
Remember that a 1NT rebid in Standard American shows 12–14 points, because a balanced 15–17 would have opened 1NT.
XYZ is a popular alternative. After any auction that starts with three one-level bids (such as 1♣ – 1♦ – 1♠), 2♣ forces opener to bid 2♦ (so responder can sign off or invite) and 2♦ is an artificial game force. Choose one method with your partner, not both.
6. Fourth suit forcing
When three suits have been bid, a bid in the fourth suit is usually artificial. It says “I have a good hand but I don’t know where we belong”, and asks partner to describe the hand further.
1♣ – 1♥ – 1♠ – 2♦
Responder may not have diamonds at all. Opener should then:
- Bid no trumps with a diamond stopper.
- Support hearts with three cards.
- Otherwise rebid a suit that describes the hand.
Most 2/1 pairs play fourth suit forcing as game forcing. Some play it as forcing for one round only. Fourth suit forcing is alertable.
Rules worth remembering
- A new suit at the two level by an unpassed responder, without interference, forces to game.
- In a game force, the slow bid is the strong bid. Jumping to game shows the weakest hand.
- After 1♥ or 1♠, 1NT is forcing for one round. A three-card limit raise starts with 1NT.
- With a balanced minimum after a forcing 1NT, rebid two of your cheaper three-card minor.
- Inverted minors: the single raise is strong, the jump raise is weak.
- When three suits have been bid, the fourth suit asks rather than promises.
- Alert forcing 1NT responses, inverted raises and fourth suit forcing.
Try these
1. Partner opens 1♥. You hold ♠ K 7 ♥ 8 4 ♦ A Q J 9 5 ♣ K 10 6 2. What do you respond?
2. Partner opens 1♠. You hold ♠ Q 8 ♥ J 9 7 6 4 2 ♦ K 5 ♣ 8 7 3. What do you respond, and what is your plan?
3. You open 1♠ with ♠ A Q 9 7 4 ♥ K 6 ♦ Q 8 3 ♣ K J 5. Partner responds 1NT (forcing). What do you rebid?
4. 1♠ – 2♦ – 2♠ – 3♠. Is this forcing? What does it suggest about responder’s hand?
5. 1♦ – 1♠ – 1NT. You hold ♠ A J 7 5 3 ♥ K 9 4 ♦ 8 2 ♣ Q 7 6. What do you bid?
Answers
1. 2♦. You have 13 HCP and a good diamond suit, so you want to be in game. 2♦ creates a game force.
2. 1NT (forcing). You’re too weak for a 2/1 response. If partner rebids 2♣ or 2♦, bid 2♥ next: a weak hand with long hearts, not forcing. If partner rebids 2♠, pass.
3. 2♣. You have a balanced 15-count with only two hearts, so you bid your cheaper three-card minor. (With 15–17 balanced and five spades, some pairs open 1NT; agree this with your partner.)
4. Yes: you’re already in a game force. Responder’s slow raise shows spade support and slam interest. With a minimum and no slam interest, responder would jump to 4♠.
5. 2♣, new minor forcing (the unbid minor). You have invitational values or better and want to know whether partner has three-card spade support. If partner bids 2♠, raise to game. If partner bids 2NT, raise to 3NT.
Words to know
| Term | Meaning |
|---|---|
| 2/1 (two over one) | A new-suit response at the two level that commits the partnership to game |
| Forcing 1NT | A 1NT response to 1♥ or 1♠ that opener may not pass |
| Principle of fast arrival | In a game-forcing auction, jumping to game shows the weakest hand |
| Inverted minors | A system where a single raise of a minor is strong and a jump raise is weak |
| New minor forcing | After opener’s 1NT rebid, the unbid minor asks about opener’s major-suit holding |
| Fourth suit forcing | An artificial bid in the only unbid suit, asking partner to describe their hand |
| Three-card limit raise | An invitational raise (about 10–12 points) with only three-card support |
What next?
- Talk to your partner. Agree that you’ll play 2/1, the forcing 1NT and either new minor forcing or XYZ. Decide whether 2/1 still applies after an overcall.
- Update your system card. Module 12 shows you where each agreement goes.
- Bid ten hands at home. Deal them out, bid them without talking, and check whether you reached the right game.
- Move on to Module 2: Raises and slam tools, which builds on the game-forcing auctions from this module.
Further reading and external documents
Official
- ABF Alerting Regulations (PDF): section 5.2 lists the alertable treatments used in this module, including the forcing 1NT, inverted minors and fourth suit forcing.