Affliction

Characters in Darkest Dungeon are not the unwavering heroes of high fantasy to which you are accustomed. While they are certainly tough and capable fighters, they are also very human and you will need to manage their Mental Health as well as their Health. As such if their Stress Bar reaches a peak, they will respond emotionally to the horrors they encounter. They get stressed, develop phobias, proclivities, and other emotional baggage. Their abilities evolve based on their experiences in the dungeons, and you must learn to lead them to victory in spite of their flaws. Sometimes, Heroes respond to the onslaught of stress by becoming Heroic. This elevated state of performance will last until they camp or return to town and confers stat bonuses and other benefits. NOTE: while this is what the game states, I've personally as of 2/22/15 gone on a long expedition and a party member became Stalwart. I had already used one of my two campfires, but after I used the 2nd, their Stalwart status remained. Unsure if this is a bug or misinformation on the game's part.

Examples
"The Jester has seen one too many party members die in combat, and is prone to nihilistic rants, stressing the other party members! Do you send him carousing in town to blow off some steam?"

"The Man-at-Arms has begun relying on the bottle as much as his battleaxe. His inebriated fury is a welcome damage boost for the party, but he has grown increasingly unpredictable and erratic. Do you bench him in town, or simply lash more liquor to his pack?"

"At camp, the Plague Doctor's methods unnerve the Highwayman, and he refuses her treatments. Maybe you should rethink the idea of combining them in the same party again."

"A critical hit from a skeleton sends the Vestal reeling, and instills in her a crippling fear of the Undead. She can fight well enough against other foes, but if you expect her to keep her head through the Crypts, you'll first need to send her to the Abbey to do some serious prayer and contemplation."

How to acquire an affliction
On max stress level up, the Hero has a chance to gain either a positive or negative Afflictions. Heroic Bonuses lower entire Party stress, while Afflictions increase the entire Party Stress.

Unlike Quirks, Afflictions can also be cured in Town when the affected party member's Stress reaches 0.

List of Afflictions

 * Paranoid
 * Selfish
 * Depressed
 * Irrational
 * Fearful
 * Hopeless
 * Abusive
 * Masochistic

List of Heroic Bonuses

 * Powerful
 * Courageous
 * Stalwart
 * Vigorous
 * Focused