Double Yukon takes the Yukon idea to its limit: two full decks dealt across ten staircase columns, no stock at all, and the family's rule that any face-up card may be moved with every card on top of it. All 104 cards are on the table from the first click. There is nothing held back, nothing to draw, and no luck left to come — what you can see, plus what you uncover, is the entire game. It is the longest patience in the Yukon family and the most purely strategic.
Scale changes the arithmetic, not the rules. Eight foundations give you twice the outlets, but the columns run deep enough that one careless move buries a low card under a dozen others. In one-deck Yukon you can often afford to undo a mistake by hand; here a badly placed tail can cost you the game twenty moves later. Think about the bottom of the column you are dropping onto, not the top.
Work the shallow left columns first. They empty soonest, and an empty column is the only place a king and its tail can go. The whole board depends on getting one or two spaces open early, and the left of the staircase is where that is cheapest.
Check both twins before committing. Every card exists twice. When you need a black 8 to host a red 7, find out which of the two black 8s is more reachable before you spend moves on either. Players used to one-deck patience routinely dig out the harder copy.
Do not send cards up early. With no stock, the tableau is your only workspace, and a card on a foundation is out of it for good. Bank aces and twos, then hold the rest until the face-down cards are gone and you can see the whole board.
Yukon's contribution to patience is a single rule: any face-up card may be moved with everything on top of it. That removes the idea of a blocked card entirely — nothing is impossible, only expensive — and it is why the family plays as a sequencing problem rather than a search. The members then vary the build rule, the empty-column rule, and the scale. Russian tightens the build to same-suit, Ukrainian lets any card fill a space, Moosehide bans a card's own suit. Double Yukon leaves every rule alone and doubles the deck, which makes it the family's endurance test: the same reasoning, sustained for two or three times as long.
Double Yukon runs in your browser — free, no download, no sign-up. Install it as an app on your phone or computer and it works offline. You get unlimited undo, a hint button that names a legal move, statistics that track your wins and times, and seeded deals: every game has a seed you can replay, so a board you enjoyed (or lost) can be played again exactly.