What is the precise definition of "showdown"?

Question

A game has the following house rule:

"All players in a showdown must show all of their cards. You may not muck your hand during a showdown even if someone has already shown a better hand."

There is no "last aggressor" rule, or any rule regarding which player(s) should show first.

The following scenario occurred during a hand:

All cards have been dealt and all betting rounds ended. Several players are all-in while two players, Player A and Player B, are not all-in. Player A and Player B have their own side pot.

The dealer collects bets and announces "show". All players show except Player A, who pushes his cards forward face-down after seeing the other hands. The dealer physically turns over Player A's cards and announces the "must show" house rule. Player A's hand is beaten by Player B's, making him not entitled to any part of the pot.

Player A says the dealer should not have turned his cards over. The dealer again states the house rule. Player A says the situation was "not a showdown". No further comments were made, as the hand was already shown and the situation could not be reversed.

The house rules do not define the term "showdown". Is there an accepted definition of the term "showdown"? Was anyone at fault in this scenario?

Answer 1

A showdown happens when all the betting is done, and it is time to show cards.

The rule you quoted

"All players in a showdown must show all of their cards. You may not muck your hand during a showdown even if someone has already shown a better hand."

is not very common anymore. However long ago it was the standard rule when it comes to showdown.

The player whom did not want to show his hand was in violation of the rule. The situation was indeed a showdown, everyone shows down whom has a hand after the last bet is made. To clarify showdown is simply the act of turning the hand up, everyone here must turn their hand up if they have a hand. No exceptions no BS, no appeal.