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Scoundrel is a modern solitaire game played with a standard deck of cards designed by Kurt Bieg and Zach Gage with the original rules available online.
Its goal is what Boardgame Geek terms Move Through Deck. Each round starts with four face-up cards called a room.
Move a room card slightly from its starting space to see the highlighted legal moves you can use it for.
You can skip a room by tapping the deck which this game calls the dungeon, causing the initial four cards to go to the bottom of the dungeon and a new set of four dealt. This is risky because you can't skip two rooms in a row, and the new room may be worse than the first.
Black cards — clubs and spades — are monsters dealing damage equal to their value, which for a jack is 11, a queen is 12, a king is 13, and an ace is 14.
Diamonds represent weapons or armour which reduce the damage inflicted by monsters by their value. There are only number diamonds available since no red royals or aces are included in the dungeon. You equip a weapon by moving a diamond from the room to the "Weapon" box, and only one weapon can be equipped at a time.
Monsters can either be moved to the discard deck — whereby your health which starts at 20 is reduced by their full value — or to the "Slain" box next to the weapon if allowed by the rules.
A clever mechanism is swords getting blunter or whatever is brought in by only allowing monsters of a lower value than the previous one slain to be placed next to the weapon. The slain pile is cleared everytime a fresh diamond is placed in the weapon space, and once it has been used on a monster, that monster limits which next monster the weapon can be used against.
Moving a heart to the discard pile increases your health by the value of the card, up to a maximum of the initial 20. Only one health potion (aka heart) works per room, the rest can simply be discarded.
Once there are three empty spaces in a room, these are refreshed with new face-up cards to form a new room, which may be skipped if you chose.
If you clear the deck with remaining health points, you win. Otherwise, you get a negative score with the value of unkilled monsters subtraced from your health to give a final score.