Soko is a variant of Five-Card Stud, the game is also known as Scandinavian- or Canadian Stud.
There is a different (expanded) hand ranking in Soko.
In stud poker each player receives a mix of downcards (only you can see these) and upcards (that everyone can see) dealt in multiple betting rounds.
All stud games starts with at least one downcard to start the “guessing game” All card are individual, there are no community cards as in hold'em games.
Stud games are also typically non-positional games, meaning that the player who bets first on each subsequent round does not necessarily have to be the same. Antes are used instead of blinds.
Soko is played with five cards, whereof only one is a downcard and four are upcards. One downcard and one upcard are dealt before the first betting round.
Thereafter one card is followed by one betting round, in total there are four betting rounds.
The best five-card poker hand – according to the hand ranking of Soko – wins the pot. This five-card poker hand is by necessity the five cards dealt to each player (there are no choices as to which cards make the best combination as in Texas Hold’em or Seven-Card Stud). Only one hand is dealt.
Note the passus “according to the hand ranking of Soko” in the above paragraph.
There are two additional sanctioned poker hands in Soko. Four-flush and four-straights beats one pair. Logically the 4-flush beats the 4-straight and both hands lose to a two pair.
Sequence of Game Play
Antes
Each player must place a forced bet, the ante, before the cards are dealt.
Starting hand
Each player receives one card face down and one card face up. The face down card is also known as the hole card, and the first open card as the door card.
First betting round
The player with the lowest ranking upcard (also by suit) has to open the betting. That player has a choice of making the bring-in bet, which is less than a full bet, or making a regular full sized bet. The action then continues clockwise.
Third street
Each player receives another card face up.
Second betting round
From now on the player with the best poker hand showing (of the upcards that is) starts the action.
Fourth street
Each player receives another card face up.
Third betting round
The betting advance as before. (In a fixed limit betting structure the bets are now doubled.)
Fifth street, river
Each player receives fifth and final card face up.
Fourth betting round
The last betting round advance as before. The hand ranking of Soko could enter the picture and decide who acts first on 5th street with four upcards.
Showdown
If more than one player reaches this stage, all remaining players show their hands. The first bettor or last raiser shows first, and then only those who beat that hand has to show. The highest ranked hand according to the Soko hand ranking wins the pot.