Osmosis Solitaire

🃏 Osmosis Solitaire (also known as Treasure Trove) is a unique single-player card game played with a standard 52-card deck. The goal is to build four foundation piles by suit, but not in the usual sequential order. Instead, cards “filter” into the foundations by matching ranks (hence the name “Osmosis”). This twist makes Osmosis both intriguing and challenging. Winning often depends on carefully freeing up cards from the reserve piles at the right time. Ready to dive in? Let’s explore how to play!

How to Play

Setup: Shuffle the deck and deal 16 cards into four reserve piles (4 cards each). In each reserve pile, place 3 cards face-down and turn the top card face-up. Next, deal one more card (the 17th) face-up to start the first foundation pile. Place the remaining cards face-down to form the stock pile. At this point you have four reserve piles (top cards visible), one foundation card, and a stock of undealt cards.
Build Foundations: The first foundation pile is already started by that 17th card (for example, an 8♠). You can play any available card of the same suit (8♠) to this foundation. The other three foundations begin empty. Each empty foundation must start with a card of the same rank as the first foundation’s card. For example, if the first foundation started with an 8, each of the other three foundations must also start with an 8 (of any suit).
Making Moves: Only the top card of each reserve pile (and the top card of the waste pile) is available to play. You may move a card to a foundation only if its suit matches the foundation’s suit and the foundation above it already contains a card of the same rank. For instance, you can play a 6♣ onto the second foundation only if the same-rank card (6♠ if in the top foundation) is already in the foundation above.
Revealing New Cards: Whenever you have moved all possible cards from the visible top cards, flip the next card(s) in the reserve piles face-up. This uncovers new cards for play. Continue moving cards from reserves to the foundations whenever the move is legal.
Using the Stock: If no moves remain from the reserve, draw from the stock. Flip three cards (or one card, if playing one-at-a-time) from the stock onto the waste pile. The top card of the waste may then be played to a foundation if it fits. When the stock is empty, you may turn over the waste pile (reshuffle it) to form a new stock – redeals are unlimited.
Winning the Game: Continue cycling cards from the stock and playing moves until all cards are in the four foundation piles. The game is won when every card has been moved to the foundations.

Rules of the Game

Deck: Use one standard 52-card deck (no jokers).
Reserve Piles: Deal 16 cards into four reserve piles of 4 cards each (three face-down, top card face-up). Only the top card of each reserve pile is playable.
Initial Foundation: After dealing the reserves, place one card (the 17th card) face-up on the first (top) foundation. This card’s rank determines the starting rank for the other foundations. The remaining three foundations start empty.
Building Foundations: All foundations are built up by suit regardless of numerical order. The three empty foundations can only start with cards that match the rank of the first foundation’s card. After a foundation has been started, you may only play a card onto it if the foundation immediately above it already contains a card of the same rank. For example, you cannot play a 5♦ to the third foundation unless the same-rank card (5♣) is already in the second foundation.
Stock and Waste: The remaining cards form the stock pile. Draw cards from the stock three at a time (or one at a time) into the waste (discard) pile. Only the top card of the waste is playable to a foundation. When the stock is exhausted, you may redeal by turning the waste pile over (reshuffled into a new stock) and continue. You can redeal the waste as many times as needed.
Objective: The goal is to move all cards into the four foundation piles. The game is successfully completed when every card has been placed on the foundations.

History of Osmosis Solitaire

Osmosis was invented by celebrated game designer Sid Sackson and first appeared in his 1969 book A Gamut of Games. Sackson was known for creating many classic games, and Osmosis (under the alternate name Treasure Trove) was one of his patented solitaire variations. For many years it remained relatively obscure in print, but it gained popularity as a computer and online solitaire. In fact, Osmosis is now featured on many solitaire websites and apps. Fans and software authors alike enjoy its distinctive “filtering” mechanic. Over time, the game has also inspired variants like Peek (where reserve cards are all face-up) and Bridesmaids. Today, Osmosis Solitaire lives on in digital collections (such as Pretty Good Solitaire and various web game sites) and continues to attract players with its clever design.

Tips and Tricks for Winning

Free the Reserve Cards: The key to success is uncovering the face-down cards in the reserve piles. Whenever possible, make moves that expose new cards. Remember: you cannot lose (i.e. be permanently stuck) if there are still covered reserve cards to play.
Avoid Blind Stock Plays: Don’t reflexively play three stock cards in a row without thinking. Changing how many cards you draw can shuffle the waste sequence and may reveal cards in a better order. A common tip is to avoid playing too many cards from the waste at once, so that on your next redeal you see different cards.
Observe Carefully: Osmosis is more a game of patience and observation than complex strategy. Always check every reserve top card and the waste for possible plays before drawing from the stock. Stay alert to available moves so you don’t miss opportunities to build the foundations.
Plan Your Suits: When starting an empty foundation, you can choose which suit to place (provided that suit isn’t already used elsewhere). Choosing suits thoughtfully can open or close future moves. For example, you might delay starting a foundation with a suit that has many cards locked in reserve, and prioritize the suit that frees up cards faster. (In general, the choice of suit for empty foundations is one of the few strategic decisions in Osmosis.)
Stay Patient: Osmosis has a relatively low win rate – on the order of 10% even with optimal play. Don’t be discouraged by losses. Each game is a new chance: use each redeal to try a different sequence of moves. With practice and careful play, you can steadily improve your win rate.

Play Osmosis Solitaire on SolitaireX

Ready to put your skills to the test? Osmosis Solitaire is available to play online right now at SolitaireX. Simply go to https://solitairex.io/osmosis-solitaire on any device and start the game immediately. SolitaireX offers a clean, responsive interface and tracks your best times and win rate. 💻🎴 Give it a try today and see how quickly you can master Osmosis!

Explore More Solitaire Games

After winning at Osmosis, be sure to check out SolitaireX’s other offerings. SolitaireX has dozens of free solitaire variants (from Klondike and Spider to quirky new games) to keep you entertained. Visit https://solitairex.io for more fun and challenging solitaire games. Happy playing!