Stronghold is Streets and Alleys with a single free cell beside the board, and that one square changes the whole feel of the game. The deal is identical: all 52 cards face up in eight piles, four of seven and four of six, with the Aces buried wherever the shuffle put them. The building is identical too — down by rank regardless of suit, one card at a time, and an empty pile takes any card. What is new is that you may park exactly one card off the board and take it back whenever you like. In a game where a blocked pile is otherwise simply blocked, that is not a small thing. Free in your browser, no sign-up.
Goal: build all four foundations from Ace to King by suit.
One cell sounds generous after Streets and Alleys. It is, but only if you keep it available.
Stronghold belongs to the open castle line that descends from Beleaguered Castle: no stock, nothing hidden, single-card moves, and a game decided entirely by the order in which you dig. It is Streets and Alleys with one reserve square, and it is catalogued that way — the PySol Fan Club collection implements it as exactly that, and it appears in Thomas Warfield's Pretty Good Solitaire, where the single cell is described as the lifeline the older game lacks.
Its twin in this catalogue is Siegecraft, which adds the same single cell to Beleaguered Castle instead — so the Aces begin on the foundations and the opening problem disappears. Playing the two in turn shows exactly what the buried Aces are worth. There is also a version of this board with two cells, called Private Lane; this catalogue does not carry it, because a third entry differing only in how many cells sit beside an identical board would be a setting wearing a name rather than a game.
One honest note on difficulty. Figures circulate for Stronghold, but none of them carries a method or a sample size, so this page does not quote one. What can be said without a citation is a matter of logic: every game of Streets and Alleys that can be won can also be won here, because the deals are identical and the cell is optional. Stronghold is easier than its parent by however much a single card of storage is worth — and no more.
For the same board without the lifeline, play Streets and Alleys; for four cells and alternating colours, play FreeCell.
One free cell. The deal, the suit-blind downward building, the single-card moves and the open spaces are all identical; Stronghold simply adds one square beside the board where a single card can be parked and later retrieved. Because the deals match and the cell is optional, any Streets and Alleys game you could win you can also win here.
Where the Aces start. Siegecraft founds the four Aces before the deal and lays out eight piles of six; Stronghold buries the Aces in the deal and lays out four piles of seven and four of six. Both have exactly one cell and the same building rule, so digging out the Aces is Stronghold's opening problem and does not exist in Siegecraft.
One. While it holds a card it refuses every other, and the card inside can be played back to the tableau or up to a foundation at any time.
No. Only the top card of a pile moves, one card per move, even when the cards beneath it are already in descending order.
Only on the foundations, which each collect a single suit from the Ace up. In the tableau any card one rank lower may be placed on a pile's top card, whatever its suit or colour.
Because with a free cell it almost never can. While the cell is empty nearly every exposed card has a legal move into it, and while it is full that card usually has a move back out, so a board is hardly ever completely locked. Rather than claim a verdict it cannot deliver, the game leaves the judgement to you.