Brozel is a method for intervening against an opposing 1NT opening bid. It features the following calls:

• Double – shows any single suit; advancer bids 2♣, after which intervenor corrects to his actual suit (or passes with clubs). This was originally played as requiring either a solid suit or a very good suit and an entry, leaving advancer the opportunity to pass with a couple of side-suit stoppers, though many partnerships now allow a weaker suit.
• 2♣ – shows clubs and hearts
• 2♦ – shows diamonds and hearts
• 2♥ – shows hearts and spades
• 2♠ – shows spades and an unspecified minor suit
• 2NT – shows clubs and diamonds
  

The convention is named loosely after its creator, Bernard Zeller.

See also

• List of defenses to 1NT