An optimal vault layout minimizes travel time, maximizes defense, and efficiently uses space. Place your most important resource production rooms (Power, Food, Water) at the top, directly below the vault door, fully upgraded and staffed with armed dwellers. This creates a 'kill corridor' for Raiders and Deathclaws. Leave a 1-wide elevator shaft on each side of your vault, and then build 3-wide rooms. Avoid building elevators directly next to each other, as this creates a path for incidents to spread quickly. Consider placing Storage Rooms or empty rooms as buffers between critical areas and dirt walls to prevent Molerat spread. Group similar training rooms together for easy dweller management.
