This is an alternative to Standard American Responses.
Opening bids 1!d or 1!h or 1!s can be game forced by responder by bidding a lower strain suit at level 2, with some conditions.

- Both partners CANNOT pass till game is bid.
- Only non-competitive bidding (Opponent before responder has passed).
- Both partners have not passed even once.
- Responder has 13+ total points.
- Lower strain suit has 4+ cards when a minor, 5+ when hearts.
Use 2NT (called Jacoby 2NT) as response, when you have 4+ of the opener’s MAJOR suit and want to quickly confirm game.

This is how it works:
Opener starts with level 1 and responder bids 2 of a lower ranking suit.
- 1!C has no game forcing
- 1!D gets response by 2!c with 4+ cards
- 1!h gets response by 2!c or 2!d with 4+ cards
- 1!s gets response by 2!c or 2!d with 4+ cards or 2!h with 5+ cards. Note this 5+ cards exception for !h response.
