How to Play Fortress Solitaire

A rare game where the tableau allows bi-directional building—each pile can grow either higher or lower in the same suit, offering strategic flexibility but also considerable challenge. The goal: Build all four Ace foundations up to Kings by suit.

Setup

1. All 52 cards are dealt into 10 tableau piles, face-up
2. Four foundation piles wait for Aces

How to play

• Build the tableau up or down by one rank, same suit; only the top card can be moved
• Any card can fill an empty tableau pile
• Play exposed cards to the foundations to build up from Ace to King by suit
• Once a card in the tableau has no other cards it can be built on, it moves automatically to a foundation pile (you can change this in Settings)
• Since each move can go a rank higher or lower, a pile's sequence can reverse direction as you play
• Continue until all cards reach the foundations or no legal moves exist

How to win

Objective: Build all four Ace foundations up to Kings by suit.

You win when all cards are built onto the four foundations. You're stuck when tableau and foundation cards cannot be moved.

Tips

• Use bi-directional building to maneuver difficult sequences
• Empty piles are valuable; keep them available for critical moves
• Try to gather long same-suit runs on one pile, since every move is a single card, not a group

Play Fortress free on Windows

CardTray is a free solitaire app for Windows that includes Fortress alongside 300+ other games. It saves every move as you play, so you can close the window and pick the game up later, replay any deal, and take on a new Daily Challenge deal every day. Browse every game in the Game Gallery.

Related games

More games from the Beleaguered Castle family:

• Street and Alleys — A fan-style game where all cards are dealt at the start with no stock pile.
• Beleaguered Castle — The four aces begin already on the foundations, and the rest of the deck sits face up across eight tableau piles.
• Castle's End — A flexible game where the foundation base rank changes each deal, and tableau cards can build either up or down in the same suit, creating unique strategic puzzles.