 A chain reaction where a single dwarf's unhappiness causes the entire fortress's population to start throwing tantrums can begin when one dwarf throws a tantrum, attacks and kills another one with many friends, which drastically affects the happiness of many more.As the fortress expands and develops, new noble positions become available.While regular dwarves will be happy with simple rooms provided to them, dwarves appointed or elected to noble positions will need more luxurious accommodation.