1. First of all, one I've heard from a friend:
The auction started:
pass - pass - 1NT! - ...
Now West had a problem: he couldn't Double because that promissed either ♣ or both red suits. So he tried 2♣, showing either ♦ or both Majors! Ofcourse, East did what he thought was best: Pass!
pass - pass - 1NT - 2♣!
pass - pass - pass
EW made some overtricks...
Once again you get proof that Dbl should not be too artificial, especially after a 3rd seat favorable 1NT opening! With Gert I play Dbl as 4M-5m or strong distributional, so we can easily Double. If partner passes, great, but if he bids we can still find 3NT (next best thing).
2. One of our opponents did this at our table:
The auction went as follows:
1♦! - 1♥ - 1♠! - 1NT?
2♠ - pass - 3♦ - Dbl
pass - 3♥ - pass - pass
(1♦ usually shows 5♦s, opps play Polish ♣)
I bid 1NT because I didn't suspect a psych at that time, and partner could've overcalled a bit light. After the 3♦ bid however, I was shaken awake, as was my partner. But how many ♠s did I have? Hard to find 4♠ now imo.
West started his singleton ♠ to his partner's Ace but didn't get his ruff (apparently East was the only one who didn't realize the psych). We made 2 overtricks, but 4M makes if you can guess the ♣s.
3. I couldn't help it, the last day against our friends from Oxford:
The auction went:
1NT! - pass - 2♦ - 2♠!
pass - 3♥ - pass? - 3♠
pass - pass - 4♥? - pass
pass - pass
(1NT = weak; 3♥ = invite+ with ♠ fit)
I lead ♦A and got an encouraging signal. Partner thought I lead from AKx and wanted me to cash the suit before declarer's losers would go away on ♠AK. I don't think I'd ask for attitude from AKx, rather count (by leading the K), but ok, we forgive him because it was the last day and we weren't 100% concentrated (nothing to win or lose anyway). After the ♦ continuation (I thought I'd get a ruff) declarer made 4♥ by discarding his ♣ losers.