Only eight cards greet you at the deal, and you build down regardless of suit with just a 15% shot at winning it all.

Congress Solitaire is one of the older two-deck patiences, appearing in card game collections as far back as the nineteenth century. Tradition ties its name to the Congress of Vienna, where diplomats were said to fill the long pauses between negotiations with a game of cards. True or not, the story fits: only eight cards are on the table when play begins, and every decision about the other ninety-six deserves careful deliberation.
The rules grant generous freedom in one place and almost none in another. Tableau piles build down regardless of suit, so nearly any card can find a temporary home, but an empty space may not be filled from the tableau — a fresh card must come from the waste instead. With a single pass through the stock and no redeals, the game is difficult, with about a 15% chance of winning. Two decks are in play, so think two or three moves ahead; that habit is what actually wins the game.
Look to Diplomat Solitaire or Forty Thieves Solitaire next if you want more of that same feeling.
If Congress's stinginess with redeals wears on you, original Solitaire offers a gentler pace.
If you run into anything odd or have an idea that would make the game better, please contact me.
Enjoy playing!
8 foundation piles: Build up in suit from Ace to King.
8 tableau piles: Build down regardless of suit. At the start of the game, each pile is dealt one face-up card.
Stock: Click to flip over cards one at a time to the waste. There are no redeals.
Waste: The top card is playable.
There are eight foundation piles.
A card can be added to a foundation pile only if it's one rank higher and the same suit as the pile's current top card, so the only card that fits on an 8 of spades is a 9 of spades. Each pile begins with an ace and is complete at the king.
Cards that become safe to play are sent to the foundations automatically, and they cannot be taken back after they have been placed.
Eight tableau piles of one card each. Every card is dealt face-up.
A card can be added to a tableau pile only if it's one rank lower than the pile's current top card, regardless of suit, so any 7 fits on an 8 of spades.
Cards on the tableau that are not covered by another card are free to be played onto the foundations or any other tableau pile.
Empty tableau spots may not be filled with a card from another tableau pile. Play the top card of the waste into the space instead.
Only one card may be moved at a time; sequences are not permitted.
There is one waste pile and the remaining cards comprise the stock.
When you click on the stock, one card from the stock is dealt to the waste. There is only one pass through the stock.
The top card of the waste can be played to the tableau or foundations.