A jury has been asked to consider whether poker is a game of skill, chance, or a combination of both.
Derek Kelly says poker is a game of skill
Club owner Derek Kelly, 46, is accused of running unlicensed poker games at the Gutshot Private Members' Club in Clerkenwell, central London.
But he has argued that poker is a game of skill and he therefore does not require a licence.
Prosecutors say that merely shuffling the cards introduces an element of chance into the game.
Mr Kelly denies two counts of contravening the 1968 Gaming Act by organising poker games at his club in January 2005.
The act says a licence is needed to host games of chance such as blackjack and roulette but not games of skill, like chess and quiz machines.
Proscecutor Graham Trembath QC told the jury at Snaresbrook Crown Court it would learn all about poker during the trial.
He said poker was a game of "mixed skill and chance", and if the jury agreed with him, then they should find Mr Kelly guilty.
He argued that before any game of poker started, the cards were shuffled.
"We would submit that once these cards are shuffled then you have introduced an element, a significant element of chance," he said.
The trial continues.