[jandrew]

It is my understanding that a player can make any bid s/he likes irrespective of whether it is in accordance with the partnership agreement. Even if that deviant bid does not qualify as a psych.
Correct me if I am wrong.

If the bid is alerted, or if the opps ask for an explanation, the correct alert or explanation should be in accordance with the partnership agreement about the bid made, despite that explanation being at odds with the actual hand.

For example: if I bid a strong NT with only 11 points - I would still explain it as 15-17 balanced.
For example: if I bid 2♥ in response to partner's opening 1NT with a void in spades - I would still explain the bid as a transfer to spades (with expectation of a 5+ spade holding).

I might be daft for making these bids, I might get a deservedly bad score, or I might keep opps out of a high-scoring contract.
BUT - such a deviant bid is not illegal (given that partner is as much in the dark as the opps) and the alert of the agreed partnership meaning is not against the rules nor illegal.

If I am wrong in some particular situations or bids - please tell me.
If I am always wrong - please quote the law which I am breaking,

[pescetom]

You are not wrong in terms of the laws of bridge, so long as you really have that agreement and your partner really is surprised by your deviation. The two examples you cite are sufficiently gross to modify an agreement even at the first occasion, IMHO.

I suspect that the 1nt deviation is illegal (the combination of bid and agreement, not the explanation) in ACBL, if the online tournament is adjudicated under their regulations.

[paulg]

It all sounds right to me.

Of course it is not what most people want to hear and this is often where the problems start, but unfortunately many players do not have a good understanding of the laws.

[johnu]

pescetom, on 2022-March-22, 10:52, said:

I suspect that the 1nt deviation is illegal (the combination of bid and agreement, not the explanation) in ACBL, if the online tournament is adjudicated under their regulations.

I think 1NT qualifies as a psych in the ACBL so legal. It is an ace less than the agreement (or 2 cards fewer than the agreement) so falls into the definition of a psych. Smaller deviations could make the range illegal (at least 10 HCP, range not greater than 5 HCP).

[pilowsky]

paulg, on 2022-March-22, 15:58, said:

Of course it is not what most people want to hear and this is often where the problems start, but unfortunately many most players do not have a good understanding of the laws.

FYP
The problem with Bridge in a nutshell.

[dsLawsd]

The ACBL, like all NBOs, can make rules for games they sponsor. In Face to Face games, they do enforce the rule about biding 1NT with a singleton (must be an A,K, or Q). I do not know about variations of more than about 1 HCP. In non ACBL play things may differ. But you always run the risk of creating a partnership agreement that would require informing the opponents. And those opponents may write a Player Memo or complain to BBO.
But otherwise, alert your agreements not your actual hand. One does best to attract good/pleasant opponents and keep a fine reputation.

[barmar]

I would consider both your examples to be psychs. And as others have said, the Laws require you to explain your agreements, not what you actually hold.

But if you make similar psychic bids frequently enough, they become implicit partnership agreements. In that case, you must include them in the explanation. And these agreements might violate regulations about acceptable agreements.