Double Russian Solitaire is Double Yukon with the build tightened to suit. Two full decks are dealt across ten columns with nothing held back — no stock, no waste — and the family's rule applies: any face-up card may be moved with every card on top of it, whatever those cards are. But a card may only land on the next-higher card of its own suit, so every card has exactly two hosts in the whole board, and both are twins. It is the family's longest game and its strictest, at the same time.
Two hosts, and they are twins. In Double Yukon a red seven has four black eights to choose from. Here the 7♠ has two 8♠s and nothing else. Before you bury either black eight under a tail, ask whether the other is reachable; a suit whose both eights are trapped is a suit you cannot build until a space opens.
Spaces are worth more than anywhere else in the family. With the suit build so strict, an empty column is often the only way to relocate a tail that is sitting on a card you need. Only a king fills one, so plan the king before you clear the column, and prefer the king whose suit has the most cards already in sequence beneath it.
The left column is your workbench. It hides nothing, so its six cards are known from the start. Empty it early if you can, or use it as the place where unpacked tails go to be sorted.
Move junk deliberately. The Yukon rule lets you carry unpacked cards anywhere, and in a suit-build game that is how you dig: lift the whole mess off a buried card, drop it on any legal host, and deal with the mess later. Make sure "later" has somewhere to put it.
Do not bank early. A card on a foundation is out of the tableau for good, and in a suit build the low cards are hosts for nothing but their own twins. Bank aces and twos; hold the rest until the hidden cards are gone.
Yukon's contribution to patience is a single rule: any face-up card may be moved with everything on top of it. The family then varies the build, the empty-column rule, and the scale. Russian Solitaire tightens the build to suit; Double Yukon doubles the deck. Double Russian does both, and the two changes compound: twice the cards to sequence, half the hosts for each. It shares Double Yukon's exact deal — the board that was re-derived from the source when this game was built — so the two can be compared move for move.
Double Russian Solitaire 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.