Waning Moon takes Forty Thieves and spreads it wider. Two decks, eight foundations and the same strict suit-by-suit building one card at a time, but the deal is thirteen columns of four: 52 cards open on the table and only 52 left in the stock. The Aces are dealt with everything else, so before any foundation can start you have to dig one out. Thomas Warfield designed it for Pretty Good Solitaire, and it has since been adopted by the PySol collection. One pass through the stock, no redeal. Free in your browser, no sign-up.
Goal: build all eight foundations from Ace to King by suit, using both decks.
Thirteen exposed tops make this the most open board in the Forty Thieves line, and the single-card rule makes every one of them precious.
Waning Moon is a Thomas Warfield design from Pretty Good Solitaire, and it keeps the classic Forty Thieves rules intact while changing only the deal: thirteen columns instead of ten, and therefore twelve fewer cards in the stock. The published rule pages at BVS, Goodsol and Solitaire Central agree on every detail, and the PySol collection carries it under the same name. It is easy to confuse with two of its neighbours. Lucas also deals thirteen columns, but only three deep, and founds all eight Aces before play begins; Thirty-Nine Steps, another PySol member, deals thirteen columns of three with the Aces left in. Waning Moon is the one with four-deep columns and every Ace still to be found.
The name is a small joke about the deal: with the stock reduced to a sliver, the part of the game you cannot see is waning from the first move.
For the same rules on the classic ten-column board, play Forty Thieves; for a gentler start with the Aces already up, play Lucas.
Only the deal. Waning Moon lays out thirteen columns of four instead of ten, so 52 cards are open from the start and the stock is 52 cards instead of 64. The suit building, the single-card moves, the one pass through the stock and the eight foundations are all Forty Thieves rules.
Lucas founds all eight Aces before the deal and lays its thirteen columns only three deep. Waning Moon leaves the Aces in the pack and deals four to a column, so every suit has to be opened by uncovering an Ace, which is where its difficulty comes from.
No. Only the top card of a column moves, one card per move, even when the cards beneath it are in perfect same-suit order.
No. The stock is turned one card at a time and only once. Cards left in the waste at the end stay there.
Any single card. Empty columns are the only place to put a stock card that has no host, so keeping one free is the main strategic resource.
More often than Forty Thieves, because thirteen exposed columns give far more room, and less often than Lucas, because the Aces must be dug out. Pretty Good Solitaire rates it a game of mostly skill. The game detects a genuine dead end and tells you when no legal move remains.