According to most sources, the player with the aces could still play them.
The most commonly reproduced set of poker rules on the World Wide Web
is Robert's Rules of Poker by the well-known poker author and expert
Robert "Bob" Ciaffone. In the General Poker Rules chapter, Rule 12
under Irregularities says "A card that is flashed by a player will
play." It also says "Procedure for an exposed card varies with the
poker form, and is given in the section for each game," but the
section on Hold'em Poker only covers irregularities in the deal, and
doesn't say anything about the consequences of a player exposing
The United States Playing Card Company has a set of Laws of Poker in
its Card Game Rules Archive. The relevant Law under Irregularities
says "There is no penalty against any player for exposing any part of
his hand, and he has no redress."
The TexasHoldem-Poker.com website has another detailed set of rules.
Rule 40 also supports the viability of the aces: "A player who
exposes his cards during the play may incur a penalty, but will not
have his hand killed."
The only dissent I found was on the Hendon Mob website. (The Hendon
Mob is a group of four English professional poker players. Their
website claims to be Europe's biggest poker portal.) A page in the
You Are the Tournament Director series described a hand where one
player raised on the river and the other player, with a better hand,
showed his cards without calling the raise. Four of the six
tournament directors who gave opinions on this situation said that the
second player should be allowed to call the raise, but two said that
by showing his hand, he killed it.
So the player with the kings is not totally without support, but it is
clear that the preponderance of authorities is on the side of the
player with the aces.
Search strings used included:
poker official rules
poker exposing cards
robert's rules of poker
poker rules irregularities
I hope this is a satisfactory answer to your question. If you need
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