- Who can call the director, when, and how. Of course, that question is wrong - the correct questions are who can draw attention to an irregularity (when, and how) and what happens after.
- When to correct misinformation, in the three cases: "you misbid", "you misexplained", and "partner misexplained" (which has two subcases: "your side won the contract" or "they did").
- There's a subnote to the last: "what is your agreement?" It's amazing how many people don't know, usually to their benefit.
- Insufficient bids, but all you need to know is "call the director. The opponents think they know the law. They don't."
- Revokes: what establishes a revoke, and in general, what's going to happen if a revoke is pointed out before it is established, and after. Again, apart from that, what you need to know is "call the director, explain the situation, answer his questions, and follow his instructions." and "you don't get to look through played tricks during the play, unless/until the director tells you to. Frankly, I never want to see a face-up card that isn't dummy or the trick in progress (or a PC, or a claim, I guess) when I get to the table. Ever." and "that applies *especially to* showing the card you should have played - double especially 'before calling the director'."
- Yes, even if the play is over, don't start turning up cards to "confirm". (okay, *one* trick. If that doesn't do it,...) Call the director. Please. (I guarantee that after all the fighting about "which trick" and cards turned up, by the time the ruling is finished, at least one player will not know how many/which tricks the defence took, and we'll have to work that out, too.)
- Major penalty cards. Yes, we'll protect you, but we shouldn't have to. And you definitely should know that the director will protect *the opponents*: "unless the director designates otherwise" (Law 50).
- When is a card played? Again, if not obvious, Call The Director. But it's good to know at least that there *are* different standards for declarer, dummy, and defenders.
- Claims: Listen, just do what the law tells you to do:
- show your hand.
- make a claim statement.
- If there's a trump out, mention it. Even if it's obvious.
- If you don't understand after a request for restatement, call the director.
- If you dispute it (apart from obvious "I get my Ace?"), call the director.
- Just call the director, don't explain what the problem is or show *your* hand until the director gets there.
- Let the director do their job. If your statement wasn't clear, or you didn't mention an odd distribution, explain to the director, but *you* put it in *the director's* hands; deal with it.
- Let the director do their job. Play has ceased and it's solely in the director's hands now; if the director asks you to show your hand, do so.
- Yes, you can - if all four players agree - play it out instead. Don't do that. (okay, that's opinion, not Law. It's still right).
- show your hand.
- And frankly, I think everybody should read the Proprieties (72-74, maybe 75) at least once a year.
The rest? CTFD, and follow her instructions. Accept her ruling (unless it's Black Letter Wrong, in which case, ask to see the Law in the FLB) and go on with the game.
Will you do better with more knowledge? Yes. Is it enough to care? IMO, no.
Okay, I do believe that you are *required to* know which charts your system is legal on (and what needs to change if you are playing at a lower chart). That does *not* mean you are required to know the charts, except for how it affects *what you play*. If you think there's a problem with what they play, CTFD and find out.
I also believe that you are *required to* know what calls of yours are Alertable, at least to the 95% level. That's harder (at least in the ACBL), I do understand. But, frankly, buy your friendly director a michelada(*) after the game sometime (warn him in advance so he has a copy of the regs) and go through your system with him. It'll take 15 minutes and, provided you take notes and read them later, you're done.
(*) If you're not from a sensible country (where they don't know how to treat a lager properly), a Caesar will do. If you're from a really benighted country that doesn't know from Ceasars either, ask. No, a Bloody Mary bloody isn't the same :-)