This is what I have managed to get from Wookiepedia
The game of sabacc used a deck of seventy six cards featuring sixty numbered cards divided into four suits, and two copies of eight special cards. Each player was passed four cards which made up their hand at the beginning of the game. The suit and value of the cards would shift to different values at random, unless they were placed in the neutral field in the center of the table.
The object of the game was to create a hand holding the value of twenty three, known as Pure Sabacc, or minus twenty three which would be trumped by a positive twenty three. Negative numbers could be created through the use of the special cards which all, with the exception of the Idiot card, represented a negative number.
At the end of their turn a player had to discard all but two of their cards. A new round began and new cards were dealt. A player won the game by either calling their hand when they had twenty three, or minus twenty three, or if their hand was below twenty three or above minus twenty three, but closer to either number than their opponent's. Anything over twenty three and under minus twenty three was a bust. A pure zero was also a bust.
Many private games and professional establishments played sabacc using "house rules". House rules used a selection of special modifications to the rules for example often stating that a player could place at most two cards in the neutral field where they were unaffected by shifting, or that an Idiot's Array, consisting of The Idiot, any two and any three would beat anything, even Pure Sabacc, and would win the sabacc pot. Another common house rule was that the bet amount was paid into the sabacc pot on bust, zero, or loss on call.
There were several styles of sabacc play, including Bespin Standard, Empress Teta Preferred, Cloud City Casino, and Corellian Gambit. Each system had slightly different rules. There was also a version where fives were wild. Other variations included Random Sabacc, in which the house rules were changed at random intervals, and Force Sabacc, which used an altered deck with Light side of the Force and Dark side of the Force themed suits.
Pure Sabacc was the term used to describe a perfect hand of positive twenty three in the high stakes card game Sabacc. The phrase also saw use as a slang term, where it was used to refer to the perfection of a situation or object.
An Idiot's array was a rare hand in some versions of sabacc consisting of the Idiot, a two of any suit, and a three of any suit. An idiot was worth nothing and the 2 and 3 rather than being added together would be read as being 23. An Idiot's array would thus trump even Pure Sabacc which was a positive score of 23.
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