Change of Call - Law 25
Unintended call -
If a player makes an unintended call, they may substitute the call that they planned to make, if they do it without pause for thought.They cannot do it if partner has made a subsequent bid or the auction has ended.
This Law only covers situations where the bid is clearly made inadvertantly. The change must be made without pause for thought. It is not meant to allow second thoughts, where the bidder has made a call they now regret.
If verbal bids are being made, the player should have spoken fairly continuously - e.g. 'Four spades... Oh Sorry, I meant four hearts'. It should clearly be a slip of the tongue.
If the player is using a bidding box, it is reasonable to claim that a bid of 4S has been made in error for 4H, as it is clearly an unintended error in picking the right bidding card. However, if the substitute bid is from a different part of the bidding box - such as Pass instead of 4S - that change should normally be rejected as it implies that the player is trying to cancel a regretted bid.
Intended call -
Apart from changing an unintended call as above, a player may only substitute a call if it is accepted by the left hand opponent (LHO), It is deemed to be accepted if LHO calls over it.
If LHO refuses to accept the change, the original call stands and the auction continues. If the player has made a replacement call, and it was not accepted, knowledge of that call is unauthorised information for the partner.
Copyright Michael O'Malley 2016