The Low Competitive

1X-pass-1Y

• DBL: Takeout
• 1NT: 16-18, stopper, balanced. Usual developments.
  
• 2X: 5+5+ in other suits, constructive
• 2Y: Natural
• 2NT: 5+5+ in other suits, offensive hand

1X-pass-2Y (2 over 1)

• DBL: Takeout with defensive hand
• 2X: 5+5+ in other suits, constructive
• 2NT: Takeout with offensive hand

1C/D-Pass-Pass

• DBL: Takeout or 14+ balanced
• Over-call: 6-14, 5+ suit (4+ at level-1)
• Jump over-call: 6+ suit, opening hand
• 1NT: 10-13 HCP, balanced. Developments as after 1NT opening.
• 2NT: 17-19 HCP, balanced. Developments as after 2NT opening.
• Cue-bid: Any game-forcing hand that prefers not to DBL
• Other: Preemptive

1H/S-Pass-Pass

• DBL: Takeout or 16+ balanced
• Over-call: 6-14 5+ suit (4+ at level-1)
• Jump over-call: 6+ suit, opening hand
• 1NT: 12-15 HCP, balanced. Developments as after 1NT opening.
• 2NT: 18-19 HCP, balanced. Developments as after 2NT opening.
• Cue-bid: Any game-forcing hand that prefers not to DBL
• Other: Preemptive

1X-1/2Y-Pass-Pass

• DBL: Takeout. Short in Y suit or any strong hand
• NT: 17-19 HCP, balanced, stopper
• 2X: 6+ suit
• Cue-bid: Asking for stopper
• New suit: Competitive, probably short in the 4^th suit (otherwise would have doubled)

Balancing after opponents stop at 1NT

• Not conventional

This occurs in the following circumstances:

• 1X-Pass-1NT-Pass-Pass
• 1X-1NT-Pass-Pass

Opponents 1NT over-call of partner's opening

• DBL: Business
• 2NT: Offensive hand, game forcing
• 2C: Takeout
  
• Other shift: Competitive
• Jump shift: Preemptive

Sandwich bids over opponents' 1NT (1X-pass-1NT)

• DBL: Takeout
• Cue-bid: 2-suiter
• 2NT: Offensive 2-suiter