Non-forcing 1NT

Opener is free to pass 1♥-1NT with a balanced minimum. The best major fit at 1♥-1NT-P is balanced 5-3. Opener can judge when to pass quite safely.

The 2♣ rebid promises 3+♣ like Wbridge5 to ensure a safe courtesy raise.

1♥-1NT-Usually 7–11, 0–3♠, 0–3♥
2♣NF, 3+♣
2♦NF, 4+♦
2♥MIN, 6+♥
2♠MAX, 4+♠
2NTBAL MAX
3♣♦MAX, 5+#
3♥MAX, 6+♥
3♠MAX, 4+♠, 6+♥

Impossible spades

As 1NT denies 4+♠, the 2♠ rebid must be artificial. The impossible 2♠ is a forcing raise that is stronger than a courtesy raise.

1♥-1NT-2♣-NF, 3+♣
2♦NF, 5+♦
2♥NF, usually 2–3♥
2♠!STR INV, 4+♣
2NTBAL INV
3♣Mild INV, usually 5+♣
3♦INV, 6+♦
3♥INV, 3=♥
1♥-1NT-2♦-NF, 4+♦
2♥NF, usually 2–3♥
2♠!STR INV, 4+♦
2NTBAL INV
3♣INV, 6+♣
3♦Mild INV, 4+♦
3♥INV, 3=♥