Eighteens

Game Objective:

The primary goal in Eighteens Solitaire is to discard all cards from the deck by forming and removing valid sets: each set consists of three cards whose values sum to 18, plus one face card (Jack, Queen, or King). Aces are discarded individually when they appear.

Setup & Layout:

• Deck: Use a standard 52-card deck. Remove Jokers.
• Tableau: Deal 12 tableau piles, each with one card face-up. All tableau cards are visible and available for play.
• Stock: Place the remaining cards face-down as the stock pile. The stock is used to refill empty tableau spaces automatically.
• Waste/Discard Pile: This is where removed sets and single aces are placed.
• Reserve: A temporary holding area where you assemble sets before discarding them.
• Foundations: There is a single foundation pile where discarded cards accumulate for tracking purposes.

Eighteens Solitaire Rules:

• Valid Set Definition: A valid set for removal consists of:
• Three cards (from 2 to 10, each of a different rank) whose values sum to exactly 18 (e.g., 5 + 6 + 7 or 4 + 5 + 9).
• One face card (Jack, Queen, or King) of any suit.
• No two cards in the set may share the same rank (e.g., 6-6-6 is not allowed).
• Aces: Single aces are discarded immediately when they appear; they do not participate in sets.
• Building: No building or sequencing is allowed on the tableau; cards are static until used in a set.
• Card Movement: Only the top card of each tableau pile is available for play. Cards cannot be moved between tableau piles.
• Refilling Tableau: When a card is removed from the tableau, the empty space is immediately filled with a card from the stock (if available).
• Stock: Cards from the stock are used only to fill tableau spaces and cannot be drawn manually.

Gameplay:

• Step 1: Examine the tableau for possible valid sets (three different-valued cards totaling 18 plus one face card) or single aces.
• Step 2: When you find a valid set or an ace, move the cards to the reserve/discard area. The cards are then transferred to the waste pile.
• Step 3: Each time a card is removed from the tableau, immediately fill the empty space with a card from the stock, if any remain.
• Step 4: Repeat steps 1–3 as long as valid sets or aces are available.
• Step 5: The game continues until either all cards are discarded or no further valid moves (sets or aces) can be made and the stock is exhausted.

Winning & Losing Conditions:

• Win Condition: The game is won when all cards have been discarded by forming valid sets and removing all aces.
• Lose Condition: The game is lost if no valid sets or aces can be removed from the tableau and the stock is depleted, leaving cards remaining on the tableau.

Special Rules & Edge Cases:

• Filling Tableau Spaces: Every time a tableau pile becomes empty, it is immediately refilled from the stock. If the stock is empty, tableau spaces remain unfilled.
• Duplicate Ranks: Sets cannot include duplicate ranks (e.g., 6-6-6 is not allowed).
• Face Card Requirement: Each set must include exactly one face card (Jack, Queen, or King), and the other three cards must be numbered 2–10 and all of different ranks.
• Aces: Aces are not used in sets; they are discarded individually as soon as they appear on the tableau.
• No Manual Stock Draw: You cannot draw cards directly from the stock; it only fills tableau gaps automatically.
• No Tableau Manipulation: You cannot rearrange or move cards between tableau piles; only removal via valid sets or aces is allowed.
• Unwinnable States: If no sets or aces are available and the stock is exhausted, the game is unwinnable and ends in a loss.

Summary of Unique Features:
Eighteens Solitaire is defined by its unique set-removal mechanic (three different cards totaling 18 plus a face card), strict tableau rules (no building or movement), and automatic tableau refilling from the stock. Its win rate is low, and success depends on careful observation and a degree of luck.