Hull Slots
Hull Slots are structural internal modules: cargo spaces, quarters, medical facilities, utility systems, laboratories, mission stores, and—on sufficiently large hulls—onboard processing machinery. Each slot has an exact physical envelope, interface family, and structural class that the fitted module must match.
A free-looking slot is not automatically compatible with every module.
Current fitting validation checks the module's physical envelope, interface family, structural class, and any required connections against the specific installation location. The S1–S5 label is physical size, not quality.
Internal space is strategy.
Hull topology decides which structural choices are actually available. Replacing cargo with better quarters, choosing a field infirmary over another support bay, or dedicating a science hull to more laboratory capability changes what the ship can sustain without outside infrastructure.