• Simple raise
• 6-9/10 points (hcp + length points)
• 4+ card support (preferably at least 5)
• No 4+ card major
• Not suited for a 1NT bid
    

• Invitational raise (also called a "limit raise")
• 10-12 points (hcp + length points)
• 4+ card support (preferably at least 5)
• No 4+ card major
• Not suited for a 2NT bid
   

After partner's minor suit opening bid is overcalled

After partner's 1/ opening is overcalled by a natural, non-jump suit bid, responder has a new set of ways to raise partner's suit.  The response structure is the same as for raising a major suit, except that we need greater trump length since 1/ openings do not promise a 5 card suit.

We must also keep in mind that despite the opponents' bidding our priorities are the same as in an uncontested auction: find a major suit fit if we have one, and try to play in NT if not.  Therefore after an overcall responder will (again in order or importance): 

1. Show a 4+ card major, either by a natural suit bid or a Negative Double
2. Bid NT with a balanced hand, a stopper in the enemy suit, and without length in an unbid major
3. Raise opener's minor

• Simple raise (meaning is unchanged)
• 6-9/10 points (hcp + length points)
• 4+ card support (preferably 5+)
• Denies 4+ cards in any unbid major
• Denies a hand suited for a 1NT response
• See Example 1
   

• Weak, preemptive raise
• No more than 7 hcp
• 5+ card support
• Shortness in a side suit, ideally a singleton or void
• This bid typically denies a major suit, but with a poor 4 card major and not enough hcp to make a negative double it is permissable to supress the major and make a preemptive raise.
• The preemptive jump raise in competition is not alertable, but when playing online I consider it courteous to type "weak" or "preemptive" in the explanation box so that the opponents know what it is intended to mean.
• See Example 2
   

    1 - (1) - 2
    1 - (1) - 2
    1 - (2) - 3

• Invitational or better raise
• 11+ points (counting hcp + length): no upper limit
• 4+ card support
• Denies having 4+ cards in any unbid major
• Not suited for a natural 2NT invitation or 3NT game bid
• This bid is artificial and says nothing about responder's holding in overcaller's suit.
• See Example Hands - 3 through 5
   
• Notes:
  • This is a standard feature of competitive auctions and does not need to be alerted.  If an opponent asks the meaning it should be explained as "inv or better raise."
  • See below for information about bidding after the cuebid.
     

Continuations after responder cuebids

After responder cuebids overcaller's suit, showing an invitational or stronger hand with support for opener's minor, opener's next bid depends on the strength and nature of his hand.

Note: the ranges listed below are approximate hcp ranges and are intended only as rough guidelines.  A much better guideline for opener is to think about how he feels about bidding game if responder has only invitational strength:

• Minimum opening hand = either unsure about game or no game interest
• Medium opening hand = wants to insist on game; might have some slam interest
• Maximum opening hand = slam interest

• Sign-off in 3 of your suit
  • See Example 3
• Sign-off in 2N with a balanced hand and stoppers in the overcalled and unbid suits (responder may correct back to 3m)
  • See Example 4
     
• Continuations by responder after a 3m sign-off:
  PLAYING IN THE MINOR....
  • Pass = invitational strength only
    • See Example 3
  • Raise to 4m = inviting game, asks opener to raise to 5m with a maximum for his 3m response
  • Raise to 5m = game values, not interested in 3NT or slam
     
  ON THE WAY TO 3NT....
  • New suit (non-jump) = natural, showing values in that suit.  Responder is interested in game (at least) and is usually looking for 3NT.
  • 3 of the enemy suit = stopper asking cuebid.  Responder is interested in game and is asking opener to bid 3NT with a stopper in overcaller's suit.  Responder should have a stopper in each unbid suit but might sometimes gamble this bid missing one.
    • See Example 5
  • 3NT = to play.  Promises game values, a stopper in the enemy suit, and a hand appropriate for NT.
       

• Continuations by responder after a 2N sign-off:
  • Pass = invitational strength only, willing to play NT
  • 3m = invitational strength only, unbalanced hand unsuitable for NT.  Opener is expected to pass.
    • See Example 4
  • 3NT = game values, willing to play NT, no slam interest opposite a minimum opening.
  • Raise to 5m = game values, not interested in 3NT or slam.  This bid is uncommon.
     

• Bid 3NT with a (semi)balanced hand and a stopper (preferably a double stopper) in the enemy suit.
• 3 of the enemy suit = stopper asking cuebid.  Asks responder bid 3NT with a stopper in overcaller's suit.  Opener should have stoppers in the two unbid suits. 
• New suit = natural, showing values in that suit.  Usually opener is looking for 3NT but is concerned about the other unbid suit.
• 4 of the minor = inviting game in the minor with a hand completely unsuited to 3NT.  Responder should raise to raise to 5m with a good invite (or better).
• Raise to 5m = An unusual bid that typically shows an extremely distributional hand with limited hcp that is willing to gamble on game.

• Do NOT bid 3 of the agreed minor as that shows a minimum opening hand and responder might pass.
   

• 3 of the enemy suit = stopper asking cuebid that asks responder bid 3NT with a stopper in overcaller's suit.  Opener will bid again over partner's response to reveal his slam interest.  Possible options over 3NT include: 4NT (natural, quantitative invite), 6NT, 4 of the agreed minor (forcing), or 4 of a new suit (a control showing cuebid).
• New suit = natural if below 3NT; a control showing cuebid if above 3NT.
• 4NT (Blackwood). Bid with extreme caution and only if you have a control in every suit.  A control is an ace, king, singleton or void.  Be particularly careful since partner's Blackwood response will often take you past 5 of your suit, forcing your side to slam.  Unless you are only concerned about trump quality, cuebidding an ace (by bidding a new suit) is almost always a better alternative to Blackwood.