- **Panel:** a three-position switch at the causeway head that decides which branch is powered, or neither.

- **Insulation:** a one-slot module that stops current, in the rack and on the surveyor.

1. *Conduction.* Current flows between touching conductors, and through water to everything the water connects. Insulation stops it.

3. *Attraction.* The relay pulses at each dispatch from whichever fixed beacon is energised, and the surge enters by that beacon; the panel alone decides which, or none. The panel powers at most one branch, but a coil discharged into a channel, or a valve that joins the two branches' channels, can energise the second branch across a dispatch; if two fixed beacons pulse at one dispatch, the surge splits between them and the forecast shows both. After entry a surge moves toward the nearest lit beacon within its sight, re-evaluated continuously; each beacon shows its reach as a glow; with none in sight it spreads along the branch it entered. The fixed beacons stand at the far ends of different branches, out of each other's sight, so switching the panel never moves a surge that has already arrived: only a beacon carried into its sight does. A dispatched surge keeps its intake. Wiring, signs and wear never change between expeditions.

| Surge behaviour: intakes, commitment, the dispatch cycle | When and where to be |

| The mystery: who left the panel on causeway, and why (the world designer's false-refuge chain) | Which place is worth the risk |

**Signature interaction (illustration).** Quiet two. The panel is on causeway, so the yard is dark: beacon dark, pump-hall hatch shut, a cable running from the yard circuit along the shallow channel to that hatch. Surge one is holding at the causeway's far end. You want the hatch. Panel route: a dash to the causeway head, yard. The yard lights up, the hatch opens and stays open, and the forecast now says surge two enters through the yard in ninety seconds, where you stand. Coil route: step into the channel's edge wearing insulation and trigger the coil; the current reaches the hatch for a few seconds, you cross, the yard stays dark, but you have spent surge one's charge, and if a dispatch lands inside your discharge window the yard beacon fires and surge two comes anyway. Electrician's route: set yard, then stand ankle-deep at the channel's edge in insulation and wait for surge two to wade in before triggering: stun, a full battery and an open hatch, because you invited the surge into the water you are standing in. Without insulation that current is yours too, which is the electrician's whole risk. The surge is bait, key and clock at once; knowing the rule is what lets you choose which.

| Minute | State | What the player is doing |

| 5 to 8 | Quiet 2 | The hatch decision above; inspect what opened |

| 10 to 12 | Quiet 3, shorter | Extract now, or spend a bundle on the pump for a dry interior route |

**Persistence.** Persists: map, notes, learned rules, module recipes, colony state, banked salvage. Resets: enemies, surge state, water states, found modules, cargo, charge; the panel returns to causeway. Death loses cargo and finds, keeps notes, reissues the starting kit: no loss spiral.

**The whole game (proposal; the scope decision the owner most needs to make).** One district and an ending. The mystery has three tiers: the false refuge (why the causeway is overrun), the interior (what the last crew went in for), and the relay's source (what calls the Flood, and whether it can be shut, redirected for good, or only held). Reaching the source and choosing what to do with it ends the game, at roughly twelve to twenty expeditions; free expeditions continue after. The title fits A literally: the colony's pump holds the Flood off one dock, and the ending is about holding it for good. The title stays provisional for the owner.

**Presentation (commitment).** One light convention: steady means powered, pulsing means dispatching, dark means unpowered; wet or dry by tint; the forecast as a screen overlay; text inspection as fallback for wear and signs. The design document will table every readable state against its cheapest medium and name any residue needing owner approval. No asset is shortlisted or claimed.

**Persistence and colony.** Notes, signal rules, equipment, banked finds persist; attention, mechanisms, enemies, carried finds reset. Finds buy a listening post (next expedition's entrances revealed) or a workshop (muffled sampler). The world rules above hold here with beacon meaning signal source and the sluice as the archive's own breach.

**Scope cuts.** One archive wing, a few authored pulse rules, marked arrival sites; no simulated acoustics, adaptive learning, procedural rooms or sound-only clues.

| | A: The Borrowed Route | B: The Listening Below |

| Where experimentation lives | One current rule across district, rack and colony | Signal timing and attention budgeting |

| Inventory | Grid with one conflicting constraint | Sockets plus cargo count |

**Recommend A.** One rule serves combat, access, routing, packing and the colony, so exploration, experimentation and mystery reinforce one another instead of competing, and the world designer's mystery drops in without a second machine family. The surge schedule keeps urgency after the mystery is solved. B gives more deliberate observation, but its pressure depends on the player choosing to escalate, which risks slow accounting and a lost survivorlike pulse. A third premise, a persistent frontier map where the colony is territory and the tide advances between expeditions, was considered and set aside because territorial loss punishes experimentation and scope grows; it can be written up if the owner wants that steer.

**Risks (unvalidated).** A: the deadline may produce anxiety rather than planning; live water, current and a surge's destination must read on a crowded screen; the panel or the shepherd's standing lure may still dominate if the invited-surge cost is too light; the sluice may make "off" a trap for new players unless the forecast shows it as clearly as the branches. B: attention accounting; over-safe clearing. Neither rhythm, balance nor repeated-expedition appeal is validated; those need an authorized later phase.

2. Carry the spine rule, the world designer's four world rules (attraction, commitment, stable evidence, turned signs) and the three thinking-room rules (notebook, shelter, live evidence) into the design document as candidate rules (recommended).

4. Fixed layout with variable placement, for fair clues (recommended).

**Owner requirements (Brief a449b2, D005 to D011):** survivorlike; exploration, experimentation, mystery; the Flood is massed enemies; assume nothing exists; Unity; Steam; design only until the owner authorizes development after reviewing the design document; no AI-generated art; prefer existing free assets; purchases and rare custom assets need owner approval.

**Provenance.** Inspirations are owner statements, not research. Both directions assume a solo player with automatic basic attacks. Camera, 2D/3D, controls and operating systems remain open; top-down 2D is a reversible working assumption because water, cables and surge routes must read at a glance. The dispatch and forecast fiction above (the relay calls the Flood on a fixed cycle; the forecast is the relay's own display; the pump runs on banked salvage) agrees with the world designer's answers, first written independently in World and Mystery r6 and aligned with this page's rules in r7; treat World and Mystery r7 or later as the shared text for the owner document, never r6.

**What r7 changes (r6 is page history 211106; the wiki editor's Q43 fix, e9eeaa, is kept).** Clarity Q43: the banner named the Design Document as draft r1, a pointer that went stale with every revision. The wiki editor removed the revision name; this revision keeps that, removes a stray parenthesis the edit left, says "which is current", and updates the header. Body unchanged; rules still live on the Design Document.

**Acknowledgment and PM report.** Lead Game and Systems Designer, new session of the role; DES101 / Design r5 / In review. Read Hub 89e2dc, Brief a449b2, Tasks 254220, Team 3ddc81, World and Mystery r7 (fa3eb1), Design Review r6 (a89227), Clarity Questions r3 (5ca22b) and the wiki editor's Glossary (f28f34) at 2026-09-06 14:33 UTC. The Glossary mirrors this page's definitions; this page is the source, and the coil entry there is corrected after this save. D011 and D012 acknowledged; design-only gate and asset restrictions accepted; no build, prototype, asset or test was made. Evidence is written reasoning against the cited revisions, not player data. Open items for PM: record the working direction (OWN101); name which of the two lead sessions is canonical (Clarity Q20); Tasks and the Hub still show DES101 and WLD101 as not started (Clarity Q15, Q16, Q19 are PM's). Next handoff: PM records the direction; the lead then writes the design document (DES102) carrying everything above; the critic reviews it when it exists; the world designer, whose r7 already aligned the world rules with the beacon-sight reading, checks the integrated draft. No owner relay, agent creation, development or testing is requested.