Most of the Forty Thieves family deals forty or fifty cards face up and asks you to dig. Double Rail deals five. Everything else — ninety-nine cards — waits in the stock and comes to you one at a time, once. To cope with that, the tableau builds down by rank regardless of suit: any six goes on any seven. Runs move as a unit, and any card may enter a space. Free in your browser, no sign-up.
Goal: build all eight foundations from Ace to King by suit.
Five columns and a suit-blind build means the board can accept almost any card that turns up — the trouble is that everything you accept lands on top of something you may need next.
PySolFC registers Double Rail as a two-deck game with five columns, a rank build and runs that move, and Single Rail as the same game with one deck, four columns and four foundations — also known as Auxiliary Sequences. Both belong to the Forty Thieves line by their shape (an open tableau over a once-through stock), but they are its most stock-heavy members: the tableau is a set of rails the stock is sorted onto, which is where the name comes from.
Like every game in this family here, the first stock card is left for you to turn rather than dealt to the waste at the start.
Because the deal is so small. Five cards face up over ninety-nine in the stock would be hopeless with a suit build; letting any 6 sit on any 7 gives the five columns enough reach to absorb most of what the stock turns up. The suits still matter on the foundations, which build in suit from the Ace.
Yes. Any packed descending sequence is a run here, and you may lift it from any card downward and move that whole tail as a unit, as long as its top card is one rank below the card it lands on.
No. The 99 stock cards are turned once. A waste card can still be played later if the board opens up for it, but the stock itself never comes back.
Anything you like. There is no king rule and no forced fill, so a space is a free slot for splitting a run or parking a card. With five columns, keeping one open for long is expensive.
Only by the deck count, which changes the whole shape: two decks give eight foundations, five columns and a 99-card stock; one deck gives four foundations, four columns and 48. Single Rail is the tighter and luckier of the two.
The four-row rank-building game Double Rail was derived from in PySolFC's source. It is marked there as an original of uncertain provenance and is not part of this catalogue; Double Rail is registered in its own right.