Play Eternal Triangle Solitaire Online — Hypotenuse Face Up

Eternal Triangle, also called Lobachevsky, is Hypotenuse with every card showing. Two decks are dealt into ten columns one to ten deep, all face up. Columns build down in alternating colours and a packed run moves as a unit; only a king, or a run headed by one, fills a space. The stock holds forty-nine cards and deals one to every column per click. Eight foundations build up in suit from the ace. Bank all 104 to win.

Setup

Shuffle two decks. Deal a staircase of ten columns, one card in the first and ten in the last, all face up. The remaining forty-nine cards form the stock; its last row reaches nine columns.

Rules

• Foundations build up in suit from the ace; each suit has two piles.
• Columns build down in alternating colours.
• Runs travel packed. A group of cards moves as a unit only when every card in it sits one rank lower and the other colour from the card beneath; a loose tail cannot be lifted.
• Only a king fills a space, alone or heading a packed run.
• The stock deals a row: one card face up to every column per click, an empty column included, as far as the cards go. There is no waste and no redeal.
• Win when all eight foundations are complete.

Strategy

Fifty-five cards are on the table and every one is visible, so the board can be read completely before the first move. The kings-only space rule makes an empty column precious: it is a home for a king and the run beneath it, and nothing else.

• Deal only when stuck. A row covers every column at once, an empty one included, and cannot be taken back except by undo. Play everything that will go before you click the stock.
• Keep runs packed. Only a packed run travels, so a card dropped out of sequence freezes everything above it until the run is rebuilt.
• Bank as you go. Foundations are one-way; a card on a foundation never blocks a column again.
• Clear the short columns. The first column is one card; emptying it and seating a king there gives that king a permanent home.
• Do not strand a king mid-column. A king with cards beneath it can only leave for a space, and there are few.
• Deal late. Forty-nine cards are five rows; each one buries every column.

Every game in this line runs on one clock: the stock. It never reshuffles and never comes back, so the number of rows left is the number of times the board can change on its own. Deal a row to reach a card you need only when no move can reach it, and before each deal read the tops of the columns, because those are the cards the row will bury. The hint button names a legal move; when it names the stock, nothing else is left.

Where It Sits in the Gypsy Line

Eternal Triangle is the Gypsy line's open ten-column staircase on the Yukon engine, the face-up form of Hypotenuse. Irmgard plays the kings-only rule on a hidden pyramid.

Other Games to Try

• Irmgard — kings into spaces on a hidden pyramid of nine
• Milligan Harp — a hidden staircase of eight
• Yeast Dough — Gypsy dealt face up
• Gypsy — the line's parent

About This Online Version

Eternal Triangle 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.