This game can be played with many variations. Romi is able to use two of them, one of which is the american standard. The second is the same but with the possibility of placing an 1(Ace) after the 13(King) as in (12,13,1). Note that (13,1,2) is not allowed. The american standard rules are used by default, but this can be change by using the item Preferências... of Romi menu.
When you begin a new game, 14 cards are drawn randomly for Romi and 14 for the player. Those last are placed on the rack in sequential order.
The player opens his game by playing at least one group of 3 cards or more, using only the cards on his rack. The sum of those cards values must be 30 or more.
After the player has opened the game, he can use the cards on the board to complete groups with cards on his rack. The player can move or reorganize all the cards on the board, but the new groups must be valid and by groups of 3 and more.