1C 1D Artificial Game Force

General

An alternate bidding style over the strong 1C opening has also been implemented. It features a "real" game-forcing 1D response, a double-negative 1S response and largely natural responses on semi-positive hands. The "strong" 1D response initiates a true game force and demands relay responses from the 1C opener. Theoretically it may be inferior to have the "strong" 1C hand being described, but in practice in the slam zone the responder is often nearly as strong as the 1C opener. The gain cases come from clearer development of auctions that should end in partscore or game depending on the degree of fit. Both hands are free to use judgement in non-forcing auctions, including passing non-natural bids where appropriate. This structure is only for use in first and second seat after a pass by the direct-seat opponent. Methods for dealing with interference by the fourth-seat opponent are described below, however the semipositive responses create a one-round force, with penalty doubles and redoubles available.

Responses to 1C

After 1C

Responder shows a game-force with 1D, a negative hand with 1S and any hand of intermediate strength with another bid that partly describes the shape.

1D Game force, 10+HCP unbalanced, 11+HCP balanced. Continuations exactly as in (symmetric continuations) with opener's AKQ base 9 and AK base 5.
1H Semipositive, 6-9 HCP unbalanced, 7-10 HCP balanced, 4+S any shape.
1S Game-invitational or better relay
1NT Balanced, or three-suited short hearts.
2C Game-forcing relay
2D 3-suited with short hearts (symmetric continuations)
2H 5S (332)
2S Game-forcing relay
2NT 5233
3C 5323
3D+ 5332
2S Balanced with both majors
2NT Game-forcing relay
3C 4423
3D+ 4432
2NT Balanced with spades and diamonds
3C Game-forcing relay
3D 4243
3H+ 4342
3C 4234
3D 4324
3H+ 4333
2C 2-suited with S and H (symmetric continuations)
2D 2-suited with S and D (symmetric continuations)
2H 2-suited with 4+S and 5+C (symmetric continuations)
2S 2-suited with 5+S and 4C (symmetric continuations)
2NT+ 1-suited with 6+S (symmetric continuations)
1NT Natural, minimum, non-forcing (with a balanced hand with extras, plan to relay once with 1H and then invite with 2NT
2C/2D/2H/2S Natural, minimum, non-forcing
2NT Unspecified mini-splinter showing at least four-card support for opener's suit, 0-1 in some side suit and values that suggest game is possible opposite a suitable hand. Partner bids Step 1 to find the shortage if this information may help find a game. The shortage is then bid according to the usual scheme, highest shortage first and down-the-line.
3C/3D/3H Fit-showing jumps, showing 6+ in the suit bid, 3+ support for parter's suit and interest in playing game.
3S 4-5 card support (depending on shape), not constructive.
games To play
1S Negative, 0-5 HCP unbalanced, 0-6 HCP balanced, any shape.
1NT Natural, non-forcing, maximum of 20 HCP
2C Artificial game-force, continuations below
2D/2H/2S/3C Natural, non-forcing
1NT Semipositive, 6-9 HCP unbalanced, 7-10 HCP balanced, balanced without spades.
2C Game-forcing relay
2D Balanced with 4-5H
2H Game-forcing relay
2S 5H (332)
2NT Game-forcing relay
3C 2353
3D 3523
3H+ 5332
2NT Balanced with hearts and diamonds
3C Game-forcing relay
3D 2443
3H+ 3442
3C 2434
3D 3424
3H+ 3433
2S+ Balanced with no major suit
2C Semipositive, 6-9 HCP unbalanced, 7-10 HCP balanced, two-suited with hearts and a minor, or three-suited without spades.
2D Game-forcing relay
2H Two-suited with hearts and diamonds
2S Three-suited with short spades
2NT+ Two-suited with hearts and clubs
2H Natural, non-forcing
2S Natural, non-forcing
2NT Natural, non-forcing, responder bids a 5-card minor suit with a minimum, and 3S/3NT with 5+ C/D and a maximum, and 3H with at least 6 hearts and game interest.
3C/3D Natural, non-forcing
3H Natural, invitational
3S Natural, serious invitation
games To play
2D Semipositive, 6-9 HCP unbalanced, 7-10 HCP balanced, two-suited with both minors, or one-suited with diamonds.
2H Game-forcing relay
2S/2NT/3C/3D/3H Natural, non-forcing
3S Natural, serious invitation
games To play
2H Semipositive, 6-9 HCP unbalanced, 7-10 HCP balanced, one-suited with hearts.
2S Game-forcing relay
2NT/3C/3D/3H Natural, non-forcing
3S Natural, invitational
games To play
2S Semipositive, 6-9 HCP unbalanced, 7-10 HCP balanced, one-suited with clubs, 0-1S or any 223/222 residual shape.
2NT Game-forcing relay
3C (322)6 and 2227 shapes
3D Game-forcing relay
3H 2236
3S 2326
3NT 3226
4C 2227
3D Remainder of normal one-suited structure
3C/3D/3H/3S Natural, non-forcing
games To play
2NT Semipositive, 6-9 HCP unbalanced, 7-10 HCP balanced, one-suited with clubs, 0-1H.
3C/3H/3S Natural, non-forcing
3D Game-forcing relay for remainder of normal one-suited structure
games To play
3C Semipositive, 6-9 HCP unbalanced, 7-10 HCP balanced, one-suited with clubs, 0-1D.
3D Game-forcing relay for remainder of normal one-suited structure
3H/3S Natural, non-forcing
games To play

Relays with a very strong hand opposite a very weak hand

After 1C 1S; 2C

2D Third negative 0-2(3)HCP any shape
2H Natural not forcing
2S Natural, not forcing
2NT 23+ balanced (Puppet Stayman and transfers)
3X Natural game forcing
2H 4M and 5+m (neither suit specified)
2S Game force relay
2NT 4S 5+D
3C 4S 5+C
3D 4H 5+D
3H 4H 5+C
Low-ranking bids promise high-ranking suits, consistent with remainder of the system.
2S Shows a hand describable with Puppet Stayman and transfers (all balanced, all long-major hands, both minors) and guarantees a rebid after any non-game bid by opener, who is not constrained to bid 2NT.
2NT Three-suited hand
3C Game force relay
3D Three-suited with short clubs
3H Three-suited with short diamonds
3S Three-suited with short hearts
3NT Three-suited with short spades
3X Shows a single-suiter of (usually) at least 7 cards.

Competitive Bidding

The primary motivation for using the 1D response to the 1C opening is to prepare the auction for competition by fourth hand. This occurs frequently when responder has a semipositive hand, and so a responder who has shown some shape information allows the strong opener a good chance at a successful auction.
After the game-forcing 1D response, normal relay interference agreements apply.
After a semipositive response, the style is to consider that responder has already given a relay response. Opener's pass is forcing at all levels, and opener's double is for penalties at all levels. If the interference is such that no more than three relay steps have been lost, then responder gives relay responses to opener's forcing pass. Otherwise responder bids naturally in context, with double for penalties.
After the negative 1S, both hands have takeout doubles of natural bids, and the general Rubensohl agreements apply.