Hull Rupture is a base builder where the base is staffed by people, and where those people are explicitly a resource rather than a character. This is the design decision that defines the game, and the developers market it as the hook rather than hiding it: "Humans Are Just Another Resource" was the title of the official press release.
Crew fill jobs across the ship. They are the labour that converts materials into resources and resources into power, and they are the hands that repair breaches and fight alongside your automated defences. Every module you build without a staffed job behind it is producing nothing, which is why crew headcount is the real constraint on how large a network you can run — not materials.
When a crew member cannot work — injured, exhausted, or assigned to a job they cannot survive — they are not written off. The game gives you two grim options: put them in front of an alien breach as a meat shield, or convert them into biofuel. The community shorthand for the whole system is the line from the Chinese store page: the little humans who cannot work can fight, and the ones who cannot fight can die.
On the galaxy map there is a third option that the developers describe as "decisive crew cuts" — certain route events can be resolved by removing personnel outright, which solves the encounter at a cost you chose rather than a cost the wave chose for you. Because the game tracks the survival of individuals, this is the point where a run's moral accounting actually starts to matter.
Crew headcount is not just a labour pool — it scales some modifiers directly. The Spikes modifier is the clearest example: it grants +1% defensive unit damage per human assigned to a ship job, scaling to roughly 400% at 400 workers. A run built around Spikes is a run where staffing every available job is itself the primary strategy, and it inverts the usual instinct to keep crew numbers low and specialised.
If you are playing a generalist run, treat crew as a budget that competes with defence: every human in a production job is a human not standing behind a barricade. If you are playing a Spikes run, do the opposite and staff aggressively. The Despot will narrate whichever choice you make in the game's characteristic deadpan, and will absolutely recommend the one that costs you more people.