haha. Obviously you bid when they overcall 3H, what kind of question is that? Play partner for some values when they preempt, he can still have a pretty good hand to pass 3H and playing him for about 6 points is not a stretch. Also he may have some heart help, RHO hasn't raised and LHO usually has 7 so we can often either double stop hearts or shut LHO out etc etc. If we were w/r I would consider passing sometimes I guess, but w/r is really its own game when it comes to stuff like this. Likewise, almost always pass (or double with a doubleton heart depending on hand) when it goes 1H p 3H. LHO can have a good hand now, and partner's max point count is quite low, especially when he has short hearts (which we know he does if we have 3 hearts). Playing him to average 6 points when he has a stiff heart and passed 1H is silly since he would have bid unless specifically 3163 or something... he is probably closer to 3 points, and we have no chance of shutting the opps our (5-4 fit). Bidding 3N here is suicide. Obviously if you have a good source of tricks and a double stopper you can make an exception but it would be quite rare. 2H p 3H is the only one where I would use some judgement based on the quality of my hand and especially my heart stopper (for instance with Axx of hearts I would always bid 3N). I would bid much more often than I would pass though for sure, partner can pass 2H with a pretty reasonable hand and LHO has advertised a weak hand. Edit: I also consider it completely standard to pass with 18-19 balanced on the auction 1C (1H) p (2H) ? lol at bidding after 1C (1H) p (3H)