[euclidz]

Declarer played a card from hand. Dummy (before declarer's LHO played a card) states "Dummy" indicating that the card should have been played from Dummy.

Does this fall within prevention?
Law 41 B. Qualified Rights
Dummy may exercise other rights subject to the limitations stated in Law 43:
2. He may try to prevent any irregularity by declarer.

If it does not fall within his right to prevent an irregularity . . . . . surely there can be no procedural penalty if Declarer is not advantaged by the correction and logically the only advantage by this correction is to the opposition in so far as they can choose whether the card is played from hand or dummy plus penalty card rules?

[VixTD]

Dummy is allowed to try to prevent an irregularity by declarer, but may not draw attention to an irregularity during play (law 43A1(b)). Once declarer has played from the wrong hand dummy must not indicate that the lead was elsewhere; this is not trying to prevent an irregularity as the irregularity has already occurred. So if dummy sees declarer make a move to play from the wrong hand they can intervene if they're quick.

I've never known anyone receive a procedural penalty for getting this wrong, as sometimes it requires split-second judgement to get it right, although I can see it may be appropriate to award one if a dummy has been warned and shows no sign of learning. Generally if the opponents accept the lead or require declarer to lead from the correct hand they have to live with their decision if it turns out to be disadvantageous to their side, although I have heard of directors awarding a split score when declarer leads from the wrong hand and a defender sleepily follows without thinking (defenders keep the table score, declarer receives and adjustment based on what would have happened had they led from the correct hand).

If declarer gains information from the infraction (such as whether an honour is covered, or whether a player thinks about covering) an adjusted score can be awarded under law 55C.

[blackshoe]

VixTD, on 2016-December-08, 07:41, said:

I have heard of directors awarding a split score when declarer leads from the wrong hand and a defender sleepily follows without thinking (defenders keep the table score, declarer receives and adjustment based on what would have happened had they led from the correct hand).

So have I. I don't think there's a legal basis for it, though.

[weejonnie]

blackshoe, on 2016-December-08, 09:16, said:

So have I. I don't think there's a legal basis for it, though.

Law 53A rather sorts things out.

A. Lead Out of Turn Treated as Correct Lead

Any lead faced out of turn may be treated as a correct lead (but see Law
47E1). It becomes a correct lead if declarer or either defender, as the
case may be, accepts it by making a statement to that effect, or if a play
is made from the hand next in rotation to the irregular lead (but see C).
If there is no such acceptance or play, the Director will require that the
lead be made from the correct hand (and see Law 47B).

Nothing about being sleepy there. In fact if being sleepy was an excuse I think I would score between 5% and 10% extra each evening playing.

[VixTD]

blackshoe, on 2016-December-08, 09:16, said:

So have I. I don't think there's a legal basis for it, though.

I haven't seen it done for a while, and I think it was only ever done in aggravated circumstances. If declarer has cut himself off from winners in dummy and leads one anyway, if I thought declarer was doing this deliberately, and that the defenders were inexperienced, I would like to take away the advantage the offenders gained if a defender followed to the irregular lead. I'd invoke laws 72B1 and 12A1.

[euclidz]

Thanks for the helpful replies