2 decks. Easy. No redeal.
Aces are moved to the foundations as they become available.
The top cards of tableau piles and the waste pile are available to play. You may build tableau piles down in any suit but the same. Only the top card of each pile may be moved. When any tableaus are empty you can fill the space using any available card.
When you have made all the moves initially available, begin turning over cards from stock.
There is no redeal.