1 deck. Easy. 2 redeals.
Robert Solitaire uses one deck (52 cards).
You have one foundation with one card dealt there at the start of the game.
The object of the game
To build the foundation up or down, regardless of suits, wrapping from king to ace, until the pile contains all 52 cards.
Turn over one card from the stock pile to the waste pile. Only the top card of the waste pile is available for play on the foundation. You may build it up or down regardless of suit. You can move only one card at a time.
You have two redeals.