Fill eight foundations and nine tableau columns from two decks, then lean on a thirteen-card reserve feeding both sides. Brace for a tough 10% win rate.

Minerva's two-deck version, also designed by Thomas Warfield. Doubling the deck brings eight foundations and nine tableau columns, plus a thirteen-card reserve that feeds the tableau and foundations from the side. The game is difficult, with a 10% chance of winning, and skill and luck both matter.
It plays closest to Minerva Solitaire itself and to Triple Minerva Solitaire, which adds a third deck on top.
If the reserve feels like too much, classic Solitaire strips back to one deck.
If you run into anything odd or have an idea that would make the game better, please contact me.
Have fun playing!
8 foundation piles: Build up from Ace to King in the same suit.
9 tableau piles: Alternating-color construction: sequences move down by alternating color. Fill empty piles with a King, or a run of cards led by a King. Each pile is dealt four cards at the start, with the first and third face-down and the second and fourth face-up.
Stock: Click to deal one card at a time to the waste pile. You get one redeal.
Waste: Top card available for play on the foundations or tableau.
Reserve: The top card is always available for play on the tableau or foundations. Thirteen cards are dealt here, face-up, at the start of the game.
There are eight foundation piles.
Any ace in the foundation may be transferred to any vacant pile.
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 a 5 of clubs is a 6 of clubs. Each pile holds at most 13 cards.
The top card of a foundation can be moved back into play if another pile will accept it.
There is one reserve, dealt thirteen cards face-up at the start. No card can be moved into the reserve. The top card can be played to the tableau or a foundation.
Nine tableau piles, each dealt four cards: the first and third face-down, the second and fourth face-up.
A card can be added to a tableau pile only if it's one rank lower and the opposite color of the pile's current top card, so the only cards that fit on a 7 of diamonds are the 6 of spades and 6 of clubs.
Cards on the tableau that aren't covered by another card are free to move to the foundation or any other tableau pile.
Only Kings may fill an empty tableau pile.
Sequences of alternating red and black cards can move together from one tableau pile to another.
There is one waste pile, and the remaining cards form the stock.
Clicking the stock deals one card to the waste. You can run through the stock twice in total, one redeal after the first pass.
The top card of the waste can be played to the tableau or foundation.