As your vault grows, you'll need to expand your infrastructure. This phase introduces more advanced rooms and the need for specialized training. Build training rooms (Weight Room for Strength, Armory for Perception, etc.) to improve your dwellers' S.P.E.C.I.A.L. stats. Start sending dwellers into the wasteland to find Caps, weapons, armor, and Nuka-Cola Quantum. Build a Medbay to produce Stimpaks and a Science Lab to produce RadAway, as these will be crucial for wasteland exploration and incident management. Consider building a second or third elevator shaft to improve dweller movement and create more defensible layouts. Keep an eye on your happiness levels; a diverse set of rooms and successful quests contribute to higher happiness.
