Roger P: It IS the same conditions - for everyone at my table.

‘Lawbreakers’ (not a word I like, given what it conjures up) can lose but don't gain. I think this particular law is ‘bad’ - uneven and random in terms of what it ‘costs’. I'd like to see it changed.

Zygmont: “even you will find it a tall task to successfully reconcile your two following statements:
(A) “(…) the PRESUMPTION should be that 3♦ says nothing about values”
(B) “(…) I don't see how my conclusion was PRESUMPTUOUS” ?”

By (A) I meant that I had concluded we should presume nothing about values - might have zero.
By (B), I meant that, despite your claim that my conclusion was presumptuous, I think my arguments show that the ‘correct’ thing to conclude, as I said, was that, absent agreement, we don't know anything about 3♦ in terms of values.

I'm not sure if you're just playing word games or actually want to have a real discussion. Perhaps my use of language was non-optimal.
I tend to believe you know what I meant in each case, but just want to find a point of argument.

But is it ethical for me to delay my play of the ace to give him the chance to change “low” to the 10? I didn't think so. It didn't feel right to me to do that. When declarer makes a ‘losing’ mistake, it's not as if I ask the declarer ‘do you want to reconsider?’.

Phil: You can “expect” anything you want. But, without specific agreement, there is clear danger of a misunderstanding. Somebody already said they thought the ‘direct’ 3♦ was ‘goodish’. And somebody else might think it's 4-5 in the pointeds.

I also alert ‘unbalaced’ 1M rebid. Most of my patners don't - then one of us post-alerts.

Tony R: “…you would give tricks back when declarer makes an illegal play, but not when he makes a legal play?”

That's correct. My position on that might have been different, but for the following occurrence.

My LHO was declarer playing some low-level suit contract. In a side suit, dummy had K10xx. Declarer led low from hand, thought a bit when partner followed, then called “low”. (I'm guessing they were thinking ten, but said “low” because ten was the ‘lower’ of their two options.)
I had stiff ace. I knew what had happened and, as I started to play my ace perforce, declarer started to say “No…”. I could have let them ‘take it back’ - but that felt completely wrong to me - so I played my ace. (all this happened in a short space of time - but the declarer's “No…” was not fast enough to be an ‘official’ retraction.)

Now the contract was made exactly - declarer used the 10 later to make a trick.

From this incident I made what now seems a rather large leap. I decided that, from then on, all legal plays at my table would be accepted by me. I know that is a self-serving viewpoint (obviously, I gain in the long run), but I blame that on the bridge gods who ‘created’ this incident.

Richard F: I think your position is valid. I simply prefer that the game exist without illegal actions.

When I can see it's ‘irrelevant’ (only true in the revoke case) I just tell them to pick it up. When it comes to ‘using’ my policy, that's by far the most common application of what happens at my table. There were two in Wuhan - and no others.

When UI is/might be involved I'll usually mention to their partner that they can't use the info. If they did not agree, I would call the director. I say “would” because, so far, that's never happened.
There have also, so far, been no UI ‘losses’ for me doing this.

I remember one case where Dan Korbel was on lead after his partner led out of turn (I think it was lead out of turn). He now confronted some UI problem and, after thought, did the ‘losing’ thing. So I achieved the same table result as I would have had I ‘enforced the rules’.

Kursat: “so l suppose you won't lead the 8 from 108xx or j8xx.”

Given that I just said “Now I MIGHT lead 8 from 108xx, or even J8xx, if I thought the risk of blowing a trick was less than the reward of helping partner.”, your comment is obviously untrue.

Whether I do so on a particular hand depends on the rest of my hand, the auction, my partner's tendencies, the strength of my partner and the strength of my opponents.

Zygmont: “In the absence of OP elaborating on his partnership's agreed distinction (usually about strength) if any between (A) 3♦ directly over X versus (B) scrambling 2N followed by a 3♦ correction, your conclusion is presumptuous.”

I disagree. In the absence of the OP saying anything, the presumption should be that 3♦ says nothing about values. This is borne out by the fact that when I ask an expert what 2N then 3♦ means in a “Scramble” situation, the first reaction is almost always a ‘break in tempo’ and/or a blank stare.
Now, many (not sure if it's ‘most’) experts know and understand about 3 HEARTS after double of 2♠. But not nearly as many have discussed, or even thought about, 2N then 3♦ after double of 2♥.
Apparently, you have. And, of course, I have. But, without advance discussion or specification, it would have no clear meaning. On a scramble auction where it does not rate to be our hand (such as (1H)P-(2♥)P, (P)X-(P) it should clearly be used to separate range.
But, on the OP auction, there is an excellent case for saying it should still be part of ‘2(+) places to play’ - and that it shows 4-card ♠ and 5-card ♦ - with a hand too weak to make a negative double (but now has some interest in game).

So, my conclusion is that I don't see how my conclusion was presumptuous. I think it fit the facts as presented.

Lee: “Scramble” means 2N = 2(+) places to play

“Lebensohl” means 2N is ‘bad’ somewhere (below the opponent's suit) and direct 3-level bid is ‘good’. However it cannot be bid by opener.

“Good/Bad” 2N is the equivalent of Lebensohl - but is ONLY bid by opener (Note: players call it this for other players - but then it should really be called “Lebensohl”).
“Bad/Good 2N” is where 2N is the ‘good’ variant and direct 3-level bid is bad.

Whatever of these is agreed (there can be more than one, depending on the situation), the partnership should discuss what it means if you bid 2N followed by bidding at or above the opponent's suit, as opposed to making that bid directly.
Most partnerships only discuss the follow-up differences after we double 2M, or after partner opened 1N (when, for most expeets, it's Transfer Lebensohl)

Btw, some have come to use Good/Bad 2N to mean that the 2N bid can be either worse or better than the 3-level bid. But I don't believe that was the original intention when the convention was named.

Julian: I agree with all you say.
My point is that it does not feel to me as if this hand was played in an expert setting. So it's not really an expert problem. I cannot construct four hands where the bidding ‘makes sense’ to me.

You mean the OP author was so exhausted by getting your name right in the title, that he had no energy left for ‘Coup’? I'll accept that - in lieu of a better explanation.

Kursat: Of course it can. Unless your spots are ‘solid’ almost anything ‘can’ happen. Many ways it can lose a trick.

I teach juniors, when leading from 4 small against NT, not to lead the highest unless the top two spots are sequential. I give the extreme example of 6432 - the lead of the 6 can cost a trick.

Now I MIGHT lead 8 from 108xx, or even J8xx, if I thought the risk of blowing a trick was less than the reward of helping partner.

If I were playing attitude leads, I'd also ‘worry’ more about leading the 3 from 10832 (because it looks so low) than I would leading the 6 from from 10865.

The opposite is true playing 4th best leads (which I prefer). From 10865 I'd worry more about leading the 5 - looks like a 5-carder. Whereas when I lead the 2 from 10832 partner knows I have a maximum of 4 - that might be sufficient information.

Tony R: Yes, these are both different. In each case above, declarer blundered, but made a LEGAL play. They had some form of mind loss - but it was somehow connected wirth bridge. On 1) maybe he thought the 10 had lost to the king; maybe he pulled the wrong card. Whatever, he made a legal play, and lost a trick he could (and did!) lose.

A revoke is a different animal. It's an ILLEGAL play. And the current law sometimes allows the transfer of a trick that would never be lost; smetimes two tricks; while sometimes there is no penalty.

If bridge were electronic (as I think it eventually will be), declarer can and will still lose the trick(s) in your examples - whether it's a mind loss or a misclick. But the revoke stuff will just disappear - I'll like that better.

“To start with, the actual laws have been inching their way towards this, with the introduction of the comparable bid for insufficient bids and bids out of turn. But it's been implemented in a structured and controlled fashion.”

Rather than “inching toward” a sensible rule, “the comparable bid” idea has led to a whole bunch of bids that are considered comparable, but really aren't. It has been and will continue to be abused.

“But take your simplistic rule. Someone opens 3♠ out of turn. The bid is cancelled. It doesn't take much imagination to see that the offender and his partner are now placed in a difficult situation. What are they meant to do? Use the UI and allow the director to provide redress? Or try to ignore the UI?”

Obviously, try to ignore the UI. That's going to be closer to ‘bridge’ than having partner barred.

“And what about the innocent side? Suppose they use the AI, but then fall on their faces, due to bad luck or perhaps poor judgment. Do they get redress?”

If the ‘extra’ info leads to a losing action, that is interesting.
One viewpoint is that it's rub-of-the-green. Just like on some hand when in one room a guess is 50-50 and one team gets it right while in the other room, the bidding makes it 90-10 - but the 10% play is the ‘winner’.
The other viewpoint is that if, without the revoke, you'd be more likely to have gotten it ‘right’, you should get it right.
This is an element I need to think about - congratulations for bringing it up!

Tom P: “Michael, I think you drastically overestimate the ability of Directors to restore equity in clubs and many lower-level tournaments.”

You may be correct. I'm not averse to having different rules for different levels of players.

Nigel K: 4♣ seems to me pretty close to normal. You have 5-card support for a vulnerable 2-level overcall. You're making it more difficult for them to unravel their fit and range. What call do you think is closer to the mark?

I doubt, on those occasions that you were “burned”, that you had a side singleton.
Zia is (or, at least was) a believer in raising even 1m with 3 - to ‘get them out of 1N’. I never went that far - but I think Zia's matchpoint record is unmatched.