1 deck. Easy. Unlimited redeals.
The object of the game
To discard all cards to the foundation.
You can build tableau piles by cards from another tableau piles, the stock and the reserve. You can move a card to an empty tableau pile or to a pile with less than 4 cards on it, if the top card of the destination tableau pile has the same rank as the card you want to move. When all four cards of the same rank are collected on a tableau pile, they are immediately discarded to the foundation.
When you have made all the moves initially available, begin turning over cards from the stock pile. 3 cards at a time are turned over from the stock. You can move cards from the stock pile to tableaus or foundations following the rule above. The stock pile can be turned over as many times as you wish. The game is won if you discard the entire deck.