Copied from MobyGames:
Darkest Dungeon is a turn-based, side-scrolling RPG with roguelike and strategy elements. You manage a maximum of 25 randomly generated characters of thirteen possible classes, grouping them into temporary parties of four, which can be sent to dungeons in search of resources and equipment. You can upgrade your town, which harbors training, healing and equipment purchasing facilities.
Characters have various stats, the most important of which is Stress. Stress leads to the gaining of negative traits and, if its levels are too severe, death. Negative traits can be gained, along with positive ones and experience, at the end of a mission. Managing Stress and negative effects is a significant part of the game. They cost large amounts of money to be healed, so you must weigh expenses with benefits - try to heal everyone and you'll soon go bankrupt. During battle, characters' positions matter greatly, likewise with their given skills.
Its storyline and aesthetics are influenced by H. P. Lovecraft, Mike Mignola's artwork and stories, and the gothic desolateness typical to Edgar Allan Poe.