A straight flush is made of five sequential cards that are all the same suit. The royal flush stands as the best possible straight flush you can make. You can make an ace-to-ten straight in any of the four suits, (spades, hearts, diamonds, clubs), but all five cards must be the same suit for the hand to qualify as a royal flush. Only four ways to make a royal flush exist in a standard 52-card poker deck. The hand occurs so infrequently, in fact, that you could play thousands of poker hands and never make a royal flush. A standard poker deck yields only four ways to make a royal flush, as the royal flush stands as the rarest of poker hands. The official definition of royal flush is a ten-to-ace straight with all five cards of matching suits. Royal flushes top all other hands in the poker hand rankings and are mathematically the rarest made hands that you can draw from a 52-card poker deck. The royal flush represents the strongest hand you can possibly make in a game of poker. What is a royal flush FAQs What is a Royal Flush?.Does a straight flush beat a royal flush?.Does a Five of a Kind Beat a Royal Flush?.