For "How to play four card poker?", much depends on which kind of poker is in question. Poker at a casino comes in two very different forms. In house games such as three card poker or casino hold'em, each player faces the dealer and a paytable. In room games such as hold'em or Omaha, players compete with each other and the casino takes a small cut of each pot. The hand rankings are shared by all of them, and the other rules vary between games.
Every poker variant ranks hands the same way, from a high card at the bottom through a pair, two pairs, three of a kind, a straight, a flush, a full house and four of a kind, to a straight flush at the top. Three card games are the exception in one detail: with fewer cards, a straight beats a flush. The ranking chart is printed in the rules of every game and worth keeping to hand.
Three card poker deals three cards to the player and three to the dealer. After an ante, the player either folds or places a play bet equal to the ante. The dealer needs a queen high or better to qualify; if it does not, the ante pays even money and the play bet is returned. An optional pair plus bet pays on the player's own hand, whatever the dealer holds. Standard advice is to play any hand of queen, six, four or stronger.
Hold'em gives each player two private cards alongside five shared ones, while Omaha deals four private cards, exactly two of which must be used.
In room games such as hold'em, Omaha and stud, players compete with each other while the casino only hosts, so skill against opponents decides results over time.
After seeing two private cards and the first three shared ones, the player either folds or calls with a bet worth twice the ante.
Pair plus pays on the strength of the player's own three cards, whatever the dealer holds, and sits apart from the ante and play contest.
The order climbs from a high card through pairs, trips, straights, flushes, full houses and quads to the straight flush, though three card games place a straight above a flush.
Yes, the best play in house games is fixed and printed in guides, such as playing any three card hand of queen, six, four or better.