| Landy - An elementary form of interference over a 1 Notrump opener 
    by the opponent. (1N) - 2C              
    2C promises 4+ cards in the major suits Further bids by advancer are: (1N) - 2C  - (P) - ? 
      
        | Advancer Bids | Meaning |  
        | Pass | Strong Clubs, to play |  
        | 2D | Temporizing bid, asking 
        overcalling partner to make 2H/S or 3H/S call |  
        | 2H/S | Natural, to play (minimum 
        hand) |  
        | 2N | Natural, showing 
        invitational values |  
        | 3C | Asks overcaller to further 
        describe hand |  
        | 3D | Natural, showing 
        invitational values |  
        | 3H/S | Natural, showing 
        invitational values |  
        | 3N | Game signoff to play |  
        | 4H/S | Game signoff to play |  Note: Some 
    advanced players use more complex bidding structures over opponent's 1N, 
    reserving the succinct Landy structure over opponent's 2N opening 
    bid. |