Choose by purpose
A city raises maximum population. A factory creates railroad connections to nearby cities, ports and factories; trains generate gold along their route. A port needs water and supports warship construction and trade ships. A defense post strengthens nearby borders. A missile silo launches missiles, while a SAM launcher intercepts incoming missiles.
The table below is a role checklist, not a cost sheet or build order. Read the live construction menu for current prices, upgrade levels, placement restrictions and mode modifiers.
Before buying
Identify the bottleneck: population limit, gold income, water access or an exposed border. Then inspect the chosen building’s current requirements. A building that solves a different problem can consume resources without addressing the immediate one. This is a planning method, not a tested optimal opening.