One unclear part of the question that creates different situations: "W opens bidding with 2H which usually shows 6-10 points and 6+ hearts"
The keys to these questions are "You are entitled to their agreements, not the contents of their hand." and "They don't have to play the same way you do." So:
- If the quote means: "West opens 2H, which by their agreement usually shows 6-10 points and 6+ hearts", then the other answers are correct:
- If West decided to open with AK A "this time" (which, even if their agreement was 6-11, would be unusual for a preempt. Aces are worth more than 4 points; AK more than 7), he deviated from his agreement, which is legal, no damage. This isn't a gross deviation (required for "psychic call"), but even psychs are legal (if monitored much more carefully than minor deviations).
- If West opened 2H with 75 AK7642 872 8, and only after making the call found the ace of clubs stuck behind the 8, it was a misbid. Again, legal, again no damage.
- If "usually" means "very rare 11s, and KQxxxx is 6", then declarer has been warned that 10 isn't a hard limit. I'd still be surprised about AK A for the reason above.
- If East would expect AK A, or has even seen West do it more than once, then their (implied) agreement isn't what they give out. Now declarer may have a case for damage.
Note that "6+" is unusual; it's uncommon for length of suits in preempts to be variable, especially on the high side. I play with one partner "good 5-card suit, any 6, poor 7" (I can't imagine better than JTxxxxx, at least when not vul vs not), for instance,but that is clearly marked on our card and is part of any explanation, because it's so odd.
- But if the quote means "West opens 2H, which I know most people play as 6-10 points and 6+ hearts" (which, see above, it's "6 with rare exceptions and almost always those exceptions are '5') - that is, if declarer assumed the agreement and didn't check - then if it turns out that this pair happens to play Schenken Club with Schenken's original style of weak 2s, that's declarer's tough luck. "If you had asked, we would have told you."
One of the few things I always ask about is a partnership's preempt style. I usually get "huh?" or, if I'm lucky "well, it'll be 2 of the top 3, ...", but knowing:
- what their suit quality agreements are
- what their outside honour agreements are
is frequently critical. If you assume it's "standard" and it's not, that's your problem, not theirs, whether it's knocking out the club ace in the wrong hand, or West having opened on AK764 and East having a fourth heart (okay, sure, likely there would be a big raise, but still), or (on a different day) assuming your AQ5 was two tricks, and losing to Kxx in East when West opened with (a perfectly systemic, for them) JT8632.