LEBENSOHL 

Lebensohl is used when opponents intervene with a natural overcall over partner's 1 NT opening.
It's purpose is to differentiate between weak competitive hands, intermediate hands and strong hands.

Responses to Lebensohl use an artificial 2NT relay bid. The general scheme is:

1. 2 level bids are merely competitive,
2. 3 level bids are forcing,
3. 3 level cue bids are Staymanic with no stopper in the overcalled suit,
4. 3 NT shows game values but no stop in the overcalled suit and no four card major.
5. 2NT is used as an artificial relay. Opener must re-bid 3 CLUBS.

Responder can pass,
   or correct by bidding a suit below the overcalled suit,
   or invite by bidding a suit above the overcalled suit,
   or cue bid,
   or bid 3NT, similar meaning as above but promising a stop in the overcalled suit.  

LEBENSOHL OVER PARTNER'S 1NT

After a natural diamond overcall (Similar for clubs)

Open Overcall Respond Meaning

1NT 2D Double PENALTY

2H/2S five card suit, to play. (NON-FORCING) 

1NT 2D  2NT RELAY, asks opener to bid 3C. (Responder can pass with weak club suit).

Opener re-bids 3 clubs

3C  pass 3D Game force, Stayman, with a diamond stop.

3H/3S Five cards with a diamond stop. (Can be treated as merely invitational or forcing)

3NT Game bid, with a diamond stop. No major.

1NT 2D  3C Game force, showing a good club suit, no major, no diamond stop.

3D Game force, Stayman, no diamond stop.

3H/3S Game force, five cards, no diamond stop

3NT Game bid, no four card major, no diamond stop.

Open Overcall Respond Meaning

1NT 2H Double PENALTY

2S five card suit, to play.

1NT 2H 2NT RELAY, asks opener to bid 3C. (Responder can pass with weak club suit).

Opener re-bids 3 clubs

3D Non-forcing, to play.

3H Game force, Stayman, with a  heart stop.

3S Five spades with a heart stop. (Can be treated as merely invitational or forcing)

3NT game force, fewer than four spades, with heart stopper.

1NT 2H  3C/3D Game force, suit, no major, no diamond stop.

3H Game force, Stayman, no heart stopper

3S Game force, 5+ card spades, no heart stopper 

3NT Game force, less than 4 card spades, no heart stopper

If opponent's use a conventional overcall, assume the anchor suit for your bids.

LEBENSOHL OVER WEAK TWOS

Opps. Partner Resp.

2H Dbl Opening hand or better; may not have 4 card spades

2S 5 card suit, to play

2NT Asks opener to bid 3C, responder will pass or bid suit ( 0-7 pts )

After opener re-bids 3C, responder can force as follows:

3H: game force, 4 card spades, heart stopper

3S: 5+ card spades (partner bids 3N or 4S)

3N: game force, less than 4 spades, heart stopper

With a strong hand, the doubler will not bid 3C

3C/D 7-11 pts, 5+ card suit

3H Game force, 4 card spades, no heart stopper

3S Game force, 5+ card spades

3NT Game force, less than 4 spades, no heart stopper.