Cappelletti (often misspelled Cappeletti, also called Hamilton and Pottage) is bridge convention used for interventions over opponents' 1NT opening. Its invention is usually attributed to Mike Cappelletti, but origin of the concept is also claimed by Fred Hamilton, John Pottage and Gerald Helms.

Over 1NT, the intervening opponent can artificially overcall in second or fourth position, showing a one-suited or a two-suited hand:

• 2♣ shows one-suited hand (usually, 6 or more hands). The partner is supposed to:
  • bid 2♦ with a weak hand, where the overcaller is supposed to correct, or
  • bid 2NT with a strong hand, (overcaller bids the suit)
• 2♦ shows both major suits (at least 5-4),
• 2♥ shows hearts and a minor,
• 2♠ shows spades and a minor,
• 2NT shows both minor suits.

See also

• List of defenses to 1NT