High dweller happiness (above 75%) provides a production bonus to all rooms. To maximize happiness: 1) Assign dwellers to rooms that match their highest S.P.E.C.I.A.L. stats. 2) Ensure a surplus of all three resources (Power, Food, Water). 3) Successfully complete incidents and quests. 4) Equip dwellers with weapons and outfits. 5) Pair male and female dwellers in Living Quarters for 'relations' (a quick happiness boost). 6) Revive fallen dwellers quickly. 7) Build a Radio Studio and assign high Charisma dwellers to broadcast. A happy vault is a productive vault, so always strive for 100% happiness.
