[adanto6840]

Years ago I played live games quite often (Vegas), and I do still play a few times a year (also Vegas). I've seen players make the request maybe 20 times total, and probably had the request granted ~50% of the time. When denied, it's usually because the cards were already intermingled in the muck, but on a few occasions it was due to the requestor exhibiting some level of 'menacing/antagonizing intent' to begin with.

You will definitely get yelled at if you attempt to flip someone's cards yourself, 100% of the time. At higher limits, it may get you removed from the game or worse. You can ask/request the dealer to show the mucked hand, though. I'd still suggest that you not request to do so -- it will almost assuredly piss someone (or multiple people) off. There are some rare occasions where it may be worth it and/or warranted, but they are few and far between.

Most common is when someone shows their hand to "half" the table immediately before mucking (at showdown), which often will cause the other half of the table to want to see too. Most dealers handle it well and just move on to the next hand while the players 'disseminate' the (usually useless) information.

[cortesoft]

I have definitely seen the dealer enforce the “show one, show all” rule. I tried googling around after your last comment, but wasn’t able to find any reference to a player’s right to see a mucked hand. Instead, I found a lot of articles about whether it is better play to show or muck losing hands, which implies it is the person’s choice.

Do you have any reference for the rule that a folded hand has to be shown on demand if play is over?

[adanto6840]

Didn't see this until today, sorry.

See here for the Texas Holdem rules that WSOP uses: https://www.wsop.com/poker-games/texas-holdem/rules/

Search for "muck" to find the relevant entry, also below for convenience:

Any player who has been a legal part of the game can ask to see a called hand, even if the cards have already been mucked. Abuse of this privilege can result in denial by the dealer. When a winning player asks to see a mucked hand, that hand will be considered live, and the winning player can lose their pot. When any other players ask to see a folded hand, the hand will remain dead.