Ten even columns lie face-up from the very first deal, and the tableau builds both up and down in suit, so patient unpicking beats hunting for luck.

Fortress of Mercy Solitaire is an easier variant of the old open patience Fortress, itself one of the earliest games to lay every card face-up on the table from the very first deal. Nothing is hidden here, which makes Fortress of Mercy a pure game of thinking: every card you will ever see is already in front of you, and the only thing between you and the win is the order in which you unpick the columns.
The deal is tidied into an even shape. All fifty-two cards fall into ten columns of five, rather than the uneven fan of the original, and two Aces are already sitting on the foundations to give you a head start. From there the four foundations climb in suit up to the King, and cards drift up to them automatically as soon as they come free.
The tableau is where the mercy lies. You may build either up or down as long as you stay within a single suit, which gives you two directions to work in and far more room to maneuver than most single-suit games allow. Empty columns accept any card, so freeing a whole column early can be the pivot that unlocks a stuck position. Move carefully, one card at a time, and a surprising share of deals will come out.
If you enjoy Fortress of Mercy, try Fortress Solitaire and Beleaguered Castle Solitaire, two more open, no-stock games, or the original Solitaire for a classic single-deck game.
If you run into anything odd or have an idea that would make the game better, please contact me.
Enjoy playing!
4 foundation piles: Build up in suit from Ace to King. Two Aces are already placed at the start, and cards move to the foundations automatically once they are available.
10 tableau piles: Each pile is dealt five cards, and every card is face-up from the beginning. There is no stock and no waste.
There are four foundation piles, two of which begin with an Ace already in place.
A card can be added to a foundation pile only if it's one rank higher and the same suit as the pile's current top card, so the only card that fits on a 5 of hearts is a 6 of hearts. Each foundation is completed from Ace to King.
The top card of each foundation can be moved back into play if another pile will accept it.
Ten tableau piles of five cards each. Every card is dealt face-up, so the entire deal is visible from the start.
A card can be added to a tableau pile only if it's one rank higher or lower and the same suit as the pile's current top card, so the only cards that fit on a 7 of clubs are a 6 of clubs or an 8 of clubs.
Only one card may be moved at a time; sequences are not permitted, so an ordered run must be relocated a card at a time.
Empty columns may be filled with any available card, which makes clearing a column a powerful way to open up a blocked layout.