Notrump becomes cuebid after a double. We still need fit-showing jumps, so
Truscott 2NT fits well.
| 1♠(X) | - |
|---|
| XX | NF BAL G/T, 10+ |
| 1♠ | Usually 5+♠ |
| 1NT! | TRF, 5+♣ |
| 2♣! | TRF, 5+♦ |
| 2♦! | TRF, 5+♥ |
| 2♥! | TRF, 8+, 3+♠ |
| 2♠ | PRE, 0–7, 3+♠ |
| 2NT! | LIM+, 4+♠ |
| 3♣♦! | CONST+, 5+#, 4+♠ |
| 3♥! | INV, 6+♥, 3=♠ |
| 3♠ | COMP, 7–9, 4+♠ |
Natural defense suffices over 1♠(1NT).
| 1♠(1NT) | - |
|---|
| X | PEN, INV+ |
| 2NT! | LIM 4+♠ or UNBAL FG |
Transfers à la Rubens applies over 1♠(2♣♦♥). Note that 2NT is natural because
we still have 2♠.
| 1♠(2X) | - |
|---|
| X | T/O |
| 2Y | NF, 5+# |
| 2♠ | NF, 3+♠ |
| 2NT | NAT, 9–11 |
| 3♥! | LIM+, 3+♠ |
| 3♠ | CONST, 4+♠ |
| 1♠(2♣) | - |
|---|
| 3♣! | INV+, 6+♦ |
| 3♦! | INV+, 6+♥ |
| 1♠(2♦) | - |
|---|
| 3♣ | INV, 6+♣ |
| 3♦! | INV+, 6+♥ |
Doubling the cuebid is penalty oriented and lead directing.
If the only known suit from (2♠) is hearts, plain Rubens suffices. X and 2NT
somehow switch roles.
| 1♠(2♠) | ♥ (+ unknown suit) |
|---|
| 2NT! | NF T/O |
| 3♣♦ | INV, 6+# |
| 3♥! | LIM+, 3+♠ |
| 3♠ | COMP, 3+♠ |
If (2♠) shows two known suits, BTU vs Unusual applies.