Rank and File, also published as Dress Parade, deals the Emperor board — ten columns of four cards, the first three face down — and then hands you the family's one great mercy: a packed sequence moves as a unit. Where Emperor makes you carry cards one at a time past thirty unknowns, Rank and File lets a whole staircase travel in a single move. That is what makes the hidden rows survivable, and it is the only rule that separates the two games.
Build packed sequences on purpose. Runs change the arithmetic completely: a card is not stuck because something sits on it, only because that something does not pack. A tidy red-black-red staircase is a tool you can lift later. A jumbled column of the same four cards is a wall. When you have a choice of hosts, choose the one that extends a run.
Chase exposures, as in Emperor — but you can now afford to. Emperor often cannot reach a hidden card because the junk on top of it has nowhere to go one card at a time. Here you can lift the whole obstruction in one move, so the hidden rows come off much faster. Prioritise the column with the fewest cards over its last face-down card.
Keep one column empty whenever you can. An empty column accepts an entire run, which makes it the most powerful square on the board. It is worth more than a small foundation gain, because it is what lets you rearrange the tableau at all.
Do not send low cards up too early. A 4 or 5 on a foundation is a card you can no longer build on. With alternating colours and long runs available, mid-rank cards are the glue of the tableau. Bank them once the hidden rows are cleared, not before.
The Forty Thieves group varies along a handful of axes — the deal shape, the build rule, how many cards may move at once, whether the stock comes round again. Rank and File and Emperor are the clearest matched pair in the whole family: identical decks, identical deal, identical build, and one rule apart. Playing them back to back is the best way to feel exactly how much a run-move rule is worth. Number Ten then takes Rank and File's rules and hides one row less, which is why it is the family's usual recommendation for a first two-deck game.
Rank and File 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.