I am in a live pub poker site here in the UK. Last night something came up and don’t know it is legal. 5 players still on the table betting was folded all the way to the small blind who raised 6 times the blind. The big blind wasn’t sure if he should call so small blind showed a jack. This led to the big blind folding. What would the rule be
In a tournament - floor or dealer would issue a warning to the player that the next time that happens they will be penalized by sitting out for one orbit but having to still pay their blinds.
In a cash game it is "frowned upon" and a warning can also be issued with a penalty being at the discretion of the floor.
Recently I saw a player show one card as he mucked and gathered the pot. His opponent said, "Hey, I want to see that other card." So, the floor was called over and instructed the dealer to show the other card as she was keeping them from the muck. It was enforcement of the "show one show all" rule which in this room refers to the cards....if you show one of them you have to show all of them.
I have personally done it on very rare occasions when I am desperate for a read and my opponent has shoved on me on the turn or river and I think my hand is very strong and should scare my opponent and I am looking for a read. So, the only action remaining is on me (no other players in the hand) - and I take the warning.
Good luck !