When people say "solitaire," this is the game they mean. Klondike is the layout that came bundled with Windows in 1990 and turned a nineteenth-century patience game into the most played card game on computers. If you learned solitaire from a parent, an office PC, or a long flight, you learned this one.
The game uses a standard 52-card deck. Cards are dealt into seven tableau columns, with each column holding one more card than the last. Only the top card of each column starts face up, and the remaining cards form the stock. The goal is to build four foundation piles, one per suit, from Ace up to King.
You move cards between tableau columns in descending order with alternating colors — red on black, black on red. When you expose a face-down card, it flips automatically, and every flip opens new options. Draw from the stock one card at a time (Turn 1) or three at a time (Turn 3) when the tableau runs dry.
Klondike sits in a sweet spot between luck and skill, and the numbers prove it. Solver studies put the share of theoretically winnable deals at roughly 79% under Turn 3 rules and closer to 82% under Turn 1 — but those figures assume you can see all 52 cards. You cannot: 21 cards start face down, and every guess about what hides beneath a column can quietly cost you the game. That gap is why real win rates land far below the theoretical ceiling, and why a Turn 1 player who converts about a third of deals is doing genuinely well. The odds page on this site breaks the whole thing down by draw mode and pass limit.
Difficulty here maps onto the two classic rule knobs: how many cards you draw and how many times you may cycle the stock. Easy deals Turn 1 with unlimited passes, so the 24-card stock never runs out of chances. Medium keeps the single-card draw but caps you at three passes, which forces you to spend waste cards deliberately. Hard is the traditional Turn 3 game with three passes — the version serious players use to test themselves, where stock alignment and pass planning decide close games.
For daily players, everything runs in the browser with nothing to install: unlimited fresh deals, undo and redo, a move counter, a timer, and win statistics that persist between sessions. If you are new, the rules page walks through a full hand from setup to the final cascade, the strategy guide covers the habits that turn near-misses into wins, and the Turn 3 page explains the draw-three game on its own terms.