Welcome to Osmosis Solitaire! This unique patience card game – also known as "Treasure Trove" – offers a fresh twist on classic solitaire. In Osmosis, you build up four foundation piles by suit, but (unlike games like Klondike) you don’t have to follow numerical order. Instead, cards of the same rank “filter down” into lower foundations only after appearing in higher ones – a quirky mechanic that inspired the name Osmosis. It’s a friendly-yet-challenging solitaire variant that’s perfect for casual play. You can even play Osmosis Solitaire online for free on SolitaireX.io, right in your browser with no downloads needed! Whether you’re new to this game or looking to improve, this guide will cover everything: the basic rules, a step-by-step walkthrough, a bit of history, plus handy tips and fun facts to boost your enjoyment.
Rules of Osmosis Solitaire (Simple Explanation)
Before jumping into gameplay, let’s outline the basic rules and layout of Osmosis Solitaire in simple terms:
- Objective: Move all 52 cards into four foundation piles by suit. To win, every card must end up on a foundation pile.
- Initial Layout: Use a standard 52-card deck. Deal four reserve piles on the table, each with 4 cards (3 cards face-down and the top card face-up). Then turn one extra card face-up to start the first foundation pile (this 17th card sets the starting rank and suit for that foundation). Place the remaining cards aside as the stock (draw pile).
- Foundations: There are 4 foundation piles built by suit. The first foundation begins with the starter card (e.g. say it’s the 7♥) and will be filled with all cards of that same suit (hearts in this example) over the game. The other three foundations start empty, and each must begin with a card of the same rank as the first foundation’s starter card. So if the first foundation started with a 7♥, the other foundations each must start with a 7 of another suit (7♣, 7♦, 7♠). After a foundation pile is started, you may continue adding cards of that same suit, but only when a card of that rank has already been placed in the foundation above it in the layout. This is the core “osmosis” rule: a foundation pile can only accept a rank once that rank has appeared in the foundation directly above it.
- Reserve Piles (Tableau): The four reserve piles on the left serve as your starting tableau. Only the top card of each reserve is available to play at any time. If a top reserve card is moved to a foundation, you then flip the next face-down card in that pile face-up, making it available. You cannot move cards between reserve piles, nor build anything on the reserves – their sole purpose is to hold cards until they can move to foundations.
- Stock & Waste: All undealt cards form the stock. When no more moves are available from the reserves, you draw from the stock. Flip one card at a time (some versions allow three at a time) from the stock onto a waste pile. Only the top card of the waste is playable at any given moment. You can play that waste card to a foundation if it meets the suit-and-rank rule (i.e. same suit as target foundation, and its rank has been unlocked by the foundation above). If a stock draw doesn’t lead to a move, the drawn card just sits on the waste. Unlimited redeals are allowed: when you reach the end of the stock, you can reshuffle or flip over the waste pile to form a new stock and continue playing.
- Moves & Play: In Osmosis, every move sends a card to a foundation. You cannot build sequences on the reserves or move cards between reserve piles – the only destination for cards is one of the four foundation piles. On each turn, play any available reserve top card or waste top card that legally fits onto a foundation. Follow the rank-filter rule strictly: for example, you can’t play a 5♦ onto its foundation unless a 5 of that rank is already present in the foundation above (say a 5♣ in the foundation above it).
- Winning: The game is won when all cards have been moved to their appropriate foundation piles by suit. If you reach a point where no cards can be moved to foundations and the stock is exhausted (with no redeals or moves left), then that game is unsolvable and ends in a loss.
Overall, Osmosis Solitaire’s rules introduce a clever constraint: you’re free to build suits on the foundations without regard to numerical sequence, but you must wait for each rank to be "unlocked" by the pile above. This means the order in which cards appear (especially in the reserves and stock) matters a lot, making some deals quite challenging. Don’t worry if this sounds a bit abstract – the step-by-step guide below will make the gameplay flow clearer!
How to Play Osmosis Solitaire – Step-by-Step Guide
Learning Osmosis Solitaire is easiest by walking through the setup and turn sequence. Here’s a simple step-by-step guide for casual players:
- Deal the Layout: Shuffle a 52-card deck. Start by dealing out 4 reserve piles on the left, each with 4 cards (3 face-down and 1 face-up on top). Next, deal one card face-up to begin the first foundation pile on the right. This single card is the foundation’s base; its suit will be the suit for that entire foundation, and its rank (value) will determine what cards the other foundations start with. For example, if you flipped over an 8♠ as the first foundation card, then spades is the suit for that first foundation, and 8 is the base rank for all foundations. Place the rest of the deck face-down as the stock pile. The initial layout is now set: four reserves (with visible top cards) on the left, and one foundation card on the right with three empty foundation spots below it. (See image below for reference to the starting layout.)
A typical Osmosis Solitaire layout at the start: four reserve piles on the left (each with a face-up top card) and the first foundation started on the right (in this example the first foundation’s base card is 7♥, so each other foundation must start with a 7 of the remaining suits). All other cards form the stock (draw pile).
Understand the Foundation Goal: Your goal is to build up the foundations by suit, eventually moving all cards there. The first foundation already has its starting card. The other three foundations are empty and must each start with a card of the same rank as that first foundation’s card. Continuing the example above, since the first foundation started with an 8♠, the other foundations can only start when you find the other three 8s (♥♦♣) and play each one into an empty foundation pile. You can build each foundation in any order of ranks as long as you stick to the suit, but you cannot play a card onto a lower foundation until a card of that rank is present in the foundation above it. Essentially, ranks have to appear in the top foundation first, then trickle down to the next, and so on – like water filtering through layers (hence “osmosis”). Keep this rank rule in mind as you play.
Make Moves from the Reserves: Look at the face-up top cards of the four reserve piles. These are your initial playable cards. If any of those cards can be moved to a foundation pile, do so. A card can be moved to a foundation if two conditions are met: (a) it matches the suit of the target foundation, and (b) the foundation immediately above that one (if any) already has a card of the same rank. For the very top foundation, condition (b) is automatically satisfied because there's no higher foundation above it – so any card of the same suit as the first foundation’s suit can be played onto it at any time. For lower foundations, you must wait until their rank is "unlocked." For example, suppose the first foundation pile has a 7♥ as base; you can play any other hearts onto that pile freely. But the second foundation (say meant for ♣) can only start once a 7 of some suit is in the first (which it is, the 7♥), and specifically it must start with the 7♣. After the 7♣ foundation is started, any club can be played onto that pile, and also now the third foundation can start when its 7 is available, and so on. At the start of the game, typically only the first foundation can accept cards (of its suit) until you manage to place the base cards on the empty foundations. Move any reserve top-card that fits these rules onto its foundation. Each time you move a reserve card, flip the next card in that reserve pile face-up (if any remain). This will potentially reveal new playable cards. Continue playing from the reserves as long as you find legal moves. Tip: It’s wise to scan all four reserve piles for any available moves whenever you play a card, as uncovering one card might enable another move elsewhere.
Draw from the Stock: If you reach a point where no reserve top cards can be played to the foundations, it’s time to use the stock. Take the top card from the stock and flip it face-up to form a waste pile (some versions flip three cards at a time into the waste, but playing one at a time is simpler for casual play). Now, check the top card of the waste: if it can be played to any foundation under the suit/rank rule, do so and then flip the next waste card (the one beneath becomes the new top). If it can’t be played, you leave it on the waste. Continue drawing one card at a time from the stock and trying to play the waste top card when possible. Unlimited redeals: When the stock is empty, gather the waste pile (all face-up cards), flip them over to form a new stock, and continue drawing again. There is no penalty for redealing; you can cycle through the deck as many times as needed. Each pass through the stock might reveal new opportunities as the order of cards changes. Use this to your advantage to eventually expose those critical cards (especially the ones that will start the empty foundations).
Keep Building Until You Win (or Get Stuck): Resume play, alternating between moving reserve cards and drawing from the stock, until one of two outcomes: victory or no moves. You win by successfully moving all cards onto the four foundations, completing each suit pile. Often, the endgame will speed up as once all foundation base ranks are in place, you can rapidly dump remaining cards of each suit. If you find yourself stuck – no playable reserve cards and no stock cards that can be placed – and you’ve exhausted the redeals, then unfortunately that deal is unsolvable and the game ends. Don’t be discouraged: Osmosis Solitaire has a low win rate (many deals simply can’t be won due to unlucky card distribution). Even expert players win only roughly 10–15% of the time. The challenge is part of the fun! If you lose, just shuffle and try again for a new experience.
That’s all there is to it. To summarize: Always move any available card from a reserve or waste to a foundation if it fits. Reveal new cards from reserves whenever possible. Use the stock to cycle through the remaining cards, looking for those crucial foundation starters and suit matches. With practice, you’ll develop a feel for when to draw or when to hold back. Osmosis Solitaire flows at a relaxed pace – it’s more about careful observation than complex strategy, making it a perfect casual game to unwind with.
Origin and History of Osmosis Solitaire
Osmosis may be an online favorite today, but it actually originated long before computer solitaire apps. In fact, the game was invented by Sid Sackson, a famous game designer, and first published in his 1969 book A Gamut of Games. Sackson’s book introduced many original games, and Osmosis (under the alternate title “Treasure Trove”) was one of his creative solitaire variations. Because it wasn’t included in the classic 19th-century solitaire compilations, Osmosis remained relatively obscure in print for years. However, it gained a second life in the digital era: early computer solitaire collections in the 1980s and 90s began featuring Osmosis, bringing it to a wider audience. For example, a popular DOS-era solitaire suite by Randy Rasa included Osmosis (listed as “Treasure Trove”) as one of its games.
As internet gaming took off, Osmosis Solitaire found its way onto many websites and apps, quickly becoming a popular online solitaire variant. Players were drawn to its unique “filtering” mechanic that sets it apart from more familiar games. Over time, enthusiasts and developers also created a few variations on the Osmosis rules (more on that below), further cementing its legacy. Today, you can find Osmosis on numerous free solitaire sites – including SolitaireX.io – which help keep this clever single-player card game alive for new generations of players. It’s a great example of how a once-obscure rule set can become a beloved classic thanks to the reach of digital gaming.
Tips and Tricks for Osmosis Solitaire
While Osmosis is governed largely by luck and patience, there are still some strategies and tips that casual players can use to improve their chances:
- Prioritize Clearing the Reserves: The face-down cards in the reserve piles are like "locked" cards you need to free. Each time you move a top reserve card to a foundation, you expose the next card in that pile – which could be the one you desperately need. So always scan the reserve piles for any possible moves first. Even if a move seems minor, making it might reveal a new card that creates further moves. The faster you uncover those hidden cards, the better your odds of success.
- Use the Stock Wisely (Draw One at a Time): If the version you’re playing allows it, draw one card at a time from the stock rather than three at once. A single-card draw gives you more control and maximizes the chances of seeing a useful card each pass. (On SolitaireX, you have options for drawing one or three cards to adjust difficulty.) When cycling through the stock, don’t rush – after each card is revealed on the waste, check if it’s playable before drawing the next. This way you won’t skip over a crucial card.
- Watch the “Rank Chain”: Keep track of which base rank you are waiting on for each foundation. Remember that no lower foundation can begin until its required starting rank is in the foundation above. For example, if you’ve started the top foundation with a 9♦, then you know each other foundation will need a 9 to start. If you’ve only placed, say, two of the 9s so far, you know there are still two more 9s hiding somewhere in reserves or stock. Plan your moves with those key cards in mind. Sometimes holding off on playing a card from the waste immediately (or choosing which foundation to start next if you have a choice of suits) can be a subtle strategic decision. In general, though, Osmosis doesn’t offer a ton of complex strategy – it’s more about vigilance and taking opportunities as they arise.
- Take Advantage of Unlimited Redeals: Unlike some solitaire games, Osmosis lets you recycle the stock indefinitely. This means you should absolutely use all the redeals you need. Each run through the deck can potentially change the order that cards become available from the waste. If you get stuck, don’t hesitate to shuffle and go through the cards again (and again). Over multiple passes, you might finally draw that one card that unlocks everything. Patience is key – after all, Osmosis is a “patience” game!
- Stay Patient and Don’t Stress Losses: As mentioned, Osmosis has a low win rate – roughly only 1 in 8 to 1 in 10 games are winnable on average. Many deals are simply unsolvable no matter what you do, due to the starting arrangement of cards. So treat each game as a fun challenge rather than something you must beat every time. If you lose, just shuffle and enjoy a fresh game. Over time, you’ll learn to recognize patterns and improve your decision-making, but there will always be a bit of luck involved. Enjoy the ride, and savor the victories when they come!
By keeping these tips in mind, you’ll maximize your enjoyment of Osmosis Solitaire. It’s a relaxing game of observation and luck more than deep strategy, which makes it perfect for unwinding. With practice, you’ll start winning more often than when you first started – but even when you don’t win, the process of filtering out those cards has its own satisfying rhythm.
Fun Facts and Variations of Osmosis Solitaire
Here are a few interesting tidbits and variations related to Osmosis Solitaire that you might find fun:
Origins of the Name: People often wonder why it’s called “Osmosis.” The term comes from science (water filtering through a membrane), and in this card game it’s a metaphor – cards of the same value slowly filter through the foundations one level at a time. You can almost visualize each rank of card seeping down from the top foundation to the bottom, one foundation at a time, which is a pretty neat concept for a solitaire game.
Alternate Names: In some classic card game books and software, Osmosis has been published under different names. The most common alternate name is “Treasure Trove,” used in sources like Sackson’s book and some old solitaire programs. Other names that have appeared include “Captain Kidd”, “Found Treasure,” and “Treasure Island,” all evoking a theme of hidden cards waiting to be discovered. So if you encounter a solitaire game with a pirate-treasure kind of name, check the rules – it might just be Osmosis!
Popular Variants: Osmosis has inspired a couple of notable variant games:
- Peek: This variant is essentially Osmosis with an easier twist – all reserve cards are face-up from the start. Nothing is hidden in the reserves, so you have full information about what cards are in each pile (hence the name “Peek”). This makes the game a bit more strategic since you can plan around which cards are where, and it generally improves your odds of winning because there’s less guesswork.
- Bridesmaids: This is another related variant, basically a simplified Osmosis. In Bridesmaids, there are no reserve piles at all – the game starts with just a foundation base card and everything else in the stock. You draw and play cards similar to Osmosis, but you don’t have those four reserve piles to manage. With fewer initial restrictions, Bridesmaids is much easier; in fact, its win rate is very high (around 50% of games or better). It’s a good option if you enjoy the suit-filtering concept but want a more forgiving game.
Difficulty and Odds: As mentioned earlier, Osmosis is considered a hard solitaire game to win. Different sources peg the win probability in the range of about 5%–15% depending on rules and skill. This is much lower than something like Klondike solitaire. But don’t let that intimidate you – the challenge is what makes a win in Osmosis feel rewarding. Every victory can feel like a small triumph of logic and luck!
Digital Popularity: Interestingly, Osmosis wasn’t widely played until it entered the digital realm. Its inclusion in solitaire software (like Peter’s Solitaire, SolSuite, or Pretty Good Solitaire) introduced it to many card game fans. Nowadays, it’s easy to find online – which brings us to our final point...
Play Osmosis Solitaire Online on SolitaireX.io
Ready to give Osmosis Solitaire a try yourself? One of the best places to play Osmosis Solitaire online is SolitaireX.io. On SolitaireX, you can jump straight into a game of Osmosis in your web browser – no downloads or sign-ups required. Just head over to the Osmosis Solitaire page on SolitaireX.io and start playing instantly.
Why play on SolitaireX? The site offers a clean, mobile-friendly interface and several features perfect for casual players:
- Custom Draw Options: Practice Osmosis in easy mode by drawing one card at a time, or challenge yourself with the traditional three-card draw. You can choose your preferred difficulty.
- Unlimited Hints and Undos: Stuck or made a mistake? SolitaireX provides a Hint button to highlight possible moves, and Undo functionality so you can backtrack and try a different approach with no penalty.
- Statistics & Leaderboards: If you’re competitive, SolitaireX tracks your gameplay stats (wins, win rate, fastest times, etc.) and even features a leaderboard. You can see how you stack up against other Osmosis players worldwide and strive to improve your best score.
- Autoplay Feature: Once the game is nearly won (only obvious moves left), you can let the Autoplay feature automatically move cards to foundations, speeding up the endgame cleanup.
- Works on Any Device: Whether you’re on a desktop, tablet, or phone, SolitaireX.io’s Osmosis Solitaire loads quickly and plays smoothly. It’s perfect for a quick game on the go or a relaxing session at home.
Give it a try – playing Osmosis Solitaire on SolitaireX is free, easy, and a great way to experience this unique card game firsthand. If you master Osmosis, SolitaireX also offers dozens of other solitaire games to explore, from classics like Spider and FreeCell to exotic variants, ensuring you’ll never run out of fun card challenges.
We hope this guide has given you a friendly introduction to Osmosis Solitaire. Now that you know how to play Osmosis Solitaire and what makes it special, shuffle up the cards and enjoy the game! May the luck of the draw be in your favor as you watch those cards filter into place. Happy playing, and good osmosis!
Sources:
- Wikipedia – “Osmosis (solitaire)”: Overview of the game and rules.
- SolitaireX – “Play Osmosis Solitaire Online Free”: Game description, rules, and tips from SolitaireX’s own guide.
- Solitairen Blog – “How to Play Osmosis Solitaire”: Detailed instructions, history (Sid Sackson’s role), and strategy advice.