Builds are machines the player assembles from reusable parts. A good build has a recognizable fantasy—storm, ricochet factory, moving furnace—not merely a higher damage number. Permanent parts let the player begin an expedition with an intention; temporary combat upgrades make that machine grow into something outrageous before the astronaut returns home.

The owner has selected connected reusable parts, mostly automatic ordinary fire, manual special abilities, shared carrying space and a full journal pause. Temporary combat upgrades reset whenever the astronaut returns aboard, alive or revived. The specific connection language, upgrade effects and limits below are proposals.

Later in the game, the astronaut leaves with a proposed **Storm Choir** rig: Threat Sensor, Pulse Projector, Impact Dynamo, Fork Relay, Arc Emitter and Capacitor. Sensor keeps Projector firing at valid targets. Its impacts feed the locally clamped Dynamo, and Fork divides that charge between an Arc discharge and Capacitor storage. This is a later rig built from six physical parts; the exact costs and charge trace are in [Mechanical Interfaces](/Hold%20The%20Flood/Mechanical%20Interfaces%20And%20Opening%20Quantities).

An identified ward vent announces one finite release into the first occupied hall. Whenever Sensor offers a valid target and Projector is ready, the ordinary shot cycles; its impact supplies the real Dynamo input. The player chooses dense lines and clears that stage's committed arrivals. In the quiet afterwards the rig offers two temporary upgrades based on what is installed:

- **Echoing Arc** gives each accepted Arc discharge a proposed two-echo target allowance. Each echo extends that same physical Arc action to another nearby valid target and adds Arc heat. It creates no signal output or usable charge.

- **Power:** the link preview refuses a configuration whose possible concurrent operating demand exceeds the rig's visible supply. Mutually exclusive link states and buffered charge/discharge states are checked separately rather than summing every theoretical maximum; any state that can truly overlap must fit. Effects already in flight still count when a mode changes.

An eligible stage is one finite, announced pressure release from an identified physical source. Closing physical access before that release commits prevents it and gives no combat-upgrade offer. It still earns safety and access, and completed work follows its owning persistence rule. Once the stage's arrivals commit, resolving it earns one temporary choice tied to the active rig. The player resolves it either by clearing all attackers committed to that release or by completing a physical seal that ends their access. Killing faster than arrivals suppresses the lane but does not end a release that still has committed attackers feeding through it. A strong build that clears the finite release before the announced peak, or a prepared player who completes its seal after release commitment but before that peak, earns immediately. Sealing stops further access; already-arrived bodies remain dangerous until cleared or separated. Break and seal offer the same choice; their combat, oxygen and access costs may differ.

Crossing the stage's escape boundary saves the astronaut but earns nothing; re-entry resumes the same unresolved stage. A resolved stage pays once for the current station arrangement and remains spent across a living return. Reopening the same seal does not create another reward. A later machinery release qualifies only when it is separately authored, announced and sourced—not because the player crossed a distance reset. Physical seal persistence follows its mechanism. Death itself pays nothing. An earned but unchosen offer expires aboard with the rest of temporary expedition power. The accepted cost is that surviving an unsuccessful fight gives no temporary help beyond retained property and knowledge, while a reachable seal after commitment may become the safer reward route. Preventive closure trades that temporary choice for safety and access; placement must make the timing and cost readable.

As an illustrative sustained outing, three to five meaningful stage choices could produce a foundation, then a branch, then refinements or changes; an optional larger authored stage may offer a rarer transformation. This is not a quota or a claim that current routes support the cadence. A short trip can earn one, while backtracking through cleared or spent areas grants none. Living return preserves those areas. Exactly where the next eligible frontier lies requires route/content support and may leave a baseline or no-upgrade approach; no first choice is guaranteed to be soon.

Offers should change behaviour: add a branch, create a return, convert a payload, move a payoff or turn stored energy into a manual climax. Small statistical improvements can support tuning later, but they should not be the defining choice. An offer fails when one answer is mandatory for every crowd shape, when its effect is hard to see, or when the player cannot explain why the machine changed.

This rhythm gives the encounter and reward systems a clean handoff. Combat provides pressure and a release; the release provides a brief paused choice; the changed machine makes the next crowd desirable. The cost is that a familiar cleared route becomes safer but cannot rebuild peak power. The next climb comes from an occupied frontier, changed death-shift geography or a larger event the player chooses to wake—not from a death reward or instant reset of the world.

| Direction | What the player sees and does | Payoff | Cost and failure risk |