One Deck Dungeon: Forêt des Ombres is an independent extension for One Deck Dungeon (you can combine the two or not).
It contains new heroes, new dungeons, new perils, new enemies and new mechanisms.
One Deck Dungeon is a "roguelike" card game - a different dungeon every time, difficult to survive, with a character that you will evolve from scratch. The game consists of different enemies and other perils. Each card describes both the obstacle to be overcome and the potential rewards. When you shuffle a card, you claim it to gain experience, an object or a skill, by placing it under the appropriate side of your character card to show its advantages.
The more time you take to explore the dungeon, the deeper you dig, the faster the difficulty will increase! If you go far enough, you'll have to fight the boss of the dungeon. Survive, and you'll be a legend!