Military Service [EGtW]

You were press-ganged into military service, and were left shaken by what you saw on the battlefield. You have proficiency with medium armor, shields, and martial weapons. You also have a random form of indefinite madness, determined by rolling on the Indefinite Madness Table in chapter 8 of the Dungeon Masters Guide. 

Source: Explorers Guide to Wildemount - Heroic Chronicles (p. 196)