The Lebensohl Convention is a convention that can be used with good effect to combat interference over an opening 1N bid. A similar system, based on Lebensohl, can be used to respond to the take-out double of a weak two bid. You can also use it after opponents has bid 1H-2H or 1S-2S.

The 2N response forces a 3C rebid which will be followed by a natural non-forcing bid (or a pass when clubs is the suit) 0-8 HCP, while any bid made at the three level show invitational values (9-11 HCP).

(2S)    - 2N - (Pass) - 3C
(Pass) - 3D ; is now not forcing, natural with long diamonds.