Contributed by Natty Bumppo (firstname.lastname@example.org)
Use a 24-card pack consisting of A-K-Q-J-10-9 in each suit. Cards rank as in American Euchre - in the trump suit the jack (right bower) is highest and the other jack of the same color is the second highest trump.
Deal one hand of five cards and turn a card on top of the deck. You play the hand, and you must either order up the turned card or name trump. If you order, turn the up card down on top of the deck; if you name trump, put it at the bottom of the deck.
You lead to the first trick. When you lead to a trick, the deck plays cards from the top: you continue turning over cards until the deck either follows suit or trumps. If the deck takes the trick, it leads the top card. When the deck leads you must follow suit if you can.
Since the deck often plays several cards when you lead to a trick, it is possible for the deck to run out of cards. If that happens, you win the remaining tricks by default.
Otherwise, play and scoring are the same as in two-handed euchre. If you take three or more tricks you score a point; if not the deck scores two points.
In any deal you can choose to "go alone". In that case, you must take all five tricks to score four points. If you lose a trick you are euchred; and if you get euchred going alone, the deck scores four points.
Note that the deck scores only by euchring you. Game is 10, and either you win or the deck wins.
Sounds simple, but it involves a higher degree of skill than nearly all other solitaire games.
Adapted with permission from The Columbus Book of Euchre, Second Edition. Copyright © 1982, 1999, Borf Books.