Then, divide this number by 54 (number of cards in a deck plus the jokers, which you need to use) and that is the number of card decks that you should combine. This will be the number of cards that should be in play in a normal game this can be exceeded in very rare circumstances (I have never seen this number exceeded). How many decks will I need? Count the total number of players in the game and multiply this by 19.
Whether or not they have distinguishable backs really doesn't matter, although if someone were exceptionally astute and observant, they could perhaps glean a modicum of information from cards with distinctive backs. You will need to combine multiple decks of regular playing cards to play this game. In short, the game has a lot of variety to it without any changes in the rules. The progression between the two is very slow, allowing for a gradual change in style. Later on, it becomes much more of a tactical game where you have to plan carefully your choices of drawing, picking up the discards of others, and your own discards. Early on, it's very much a speed race where the goal is to empty your hand quickly.
The game has a nice mix of elements and changes greatly as the game progresses. Shanghai's distinguishing factor is the concept of goals that each player has to achieve with each hand. Shanghai rummy is a very interesting rummy game that combines elements of gin rummy and other card games.
