Hold the Flood — Power and Attraction: the shared rule contract

r3 · 2026-09-06 · Lead Game and Systems Designer · In review · The rules every district must obey. r3 embodies PMR004's provisional decisions D023 and D024, the critic's REV104-1, -3 and -4, and the lead's dispositions of the Combat and Equipment proposals (R1 to R10, E1 to E8), and records which page now owns each rule. Validated against Design Document r15 (5f9fbb), World and Mystery r20 (7699de), Combat Rules r2 (1126c3), Enemies r3 (0822dd), Inventory and Charge r1 (73eb77) and Colony r1 (a1046d). Design Index · Expansion Brief · Campaign (DES104) · Design Document · World and Mystery · Combat Rules · Inventory and Charge · Enemies · Glossary

What this page is. The one statement of the shared rules, which every district, enemy, item and colony service must obey. Everything here is a proposal and nothing is owner-approved or played. A district may add to this contract with a readable signal and the choice the addition improves, published as a shared-rule diff (section 7); it may not change what power, signal, a beacon or charge means. Where this page states a rule in one sentence and a domain page states it in full, the domain page owns the detail and this page owns the sentence; the ownership map is in section 10.

What r3 changes, in one paragraph. The rack is eight cells from the outset and pickups go to a battery order the player sets at a shelter (D023, adopting EQP101 E1 and E3); leakage, links and field handling are as Inventory and Charge states them (E2, E4, E5). A local dispatch needs the district's drum and the trunk's permission, arrivals also need supply, and a flash with nothing behind it is a readable state (D024, REV104-1 and -3). Fixed power has a stated source under the provisional Answer A, with the Stop consequence and the baseline return (D024, REV104-4, COL-I4). Bodies resolve their reasons to move in one order (R1), press is bounded by crowd size (R2), a discharge keeps water energised for two seconds (R3 ruled), roles read by silhouette and glow carries one bit (R4), a Carrier can take a mote (R5), the arc chains body to body only (R10 declined, the bounded model adopted), and one role may darken a beacon (R9 allowed). The old "two empty batteries fill together" cost is gone with the most-room rule.

1. Conduction: water connects

• Current present anywhere in a body of connected water is present everywhere in it. Two channels are one body when a valve, lock or breach joins them and both hold water. A dry bed does not conduct; a drained connection is no connection. Flowing water conducts exactly as still water does; a channel that carries no current is unenergised, not non-conducting, and a district that wants a break in conduction must draw a dry one.
• Ways to change the topology, all readable on the ground: a valve (joins or parts two channels), a drain or field pump (empties a channel), a lock (moves water between basins), the hand pump (a carried drain, section 5), and the cable reel (a laid conductor between two wet points across dry ground; it carries environmental power only and never charges a battery).
• In the rack, only orthogonal cell contact conducts. Equipment housings do not conduct, so any module, the insulation included, and any empty cell breaks a salvage chain; wet salvage bundles conduct into touching bundles, and a battery leaks one unit per minute per wet bundle reachable from its terminals through such a chain, capped at the charge present, shown as one drip per bundle. Two batteries reaching the same chain both leak; leakage never powers anything and never hurts the surveyor. Insulation worn as a module is also what lets the surveyor stand in energised water. (Owner of the detail: Inventory and Charge, E2.)
• These are game rules and not a claim about real electrical safety; the Reference pages on electricity in water and drainage engineering record the caveats.

Readable signal. Wet is wet on screen; energised water shows local arcs along its edges and contacts; a joined channel's lamp, where one exists, is an indicator.

2. Power: a device works while its channel carries current

• A device works only while the water, rail or line it stands on carries current, and stops when the current stops. Devices: dispatch beacons, hatches and doors, gates, pumps, lifts and indicator lamps.
• Sources of current: a district's own circuit, switched from its panel, whose positions choose which branch is powered and are exclusive (one branch at a time, or off); and a coil discharge, which energises the water the surveyor is touching for two seconds and stuns the conducting bodies in it for eight (section 4). The thick cable is the power line; switching it is instant and priced by what it darkens as well as by what it lights.
• What supplies the district circuits (provisional, D024, Answer A). The city runs on charge harvested from the Flood: the Collector's wheels take charge from the mass passing through, the head-works' switch-house stores and distributes it along the thick cables, and each district's panel switches its share. The store is what makes fixed power feel fixed: it outlasts any one expedition. The Stop position at the head-works ends the harvest, and the districts go dark one by one as the store drains (section 9); no district may depend on a supply the table in section 9 does not name.
• The relay is the one stated exception in the districts so far: it is a source of signal, not a consumer of power. Its drum is turned by a wheel in flowing water, the race above the weir, which nothing energises because no lit circuit joins it and the valves join only below the weir; drain R stops the wheel and touches no power (World and Mystery r18, closing REV103-9). The exception is readable: the wheel turns in water that shows no arcs.
• A role may darken a beacon. The Grounder (Enemies) climbs a live cable run and grounds it, so the beacon on that run flickers and goes dark until the body is cleared or the branch re-switched. This passes section 7's test: it makes a device stop for want of current, and can never make a light, cause a dispatch or select an intake. Its signal is an irregular flicker that is visibly not the travelling dispatch pulse, a spark at the body's position on the thick cable, and the forecast marking the branch failing (R9 allowed; World owns the body's fiction).

Readable signal. Steady light means powered; dark means unpowered; the thick cable is visibly thick.

3. Attraction: the signal chooses the intake; light draws the crowd

• Dispatch (D024, REV104-1). A district dispatches when its drum's contact closes and the trunk is carrying time: the drum makes the moment, the trunk permits it. Shut stops the drum; a dark position on the Exchange's bank withholds the trunk; either alone stops announced surges. A dark district is in the shut regime, unannounced trickles that grow and a dark forecast, and never a district with no Flood in it.
• Intake and supply (REV104-3). At a dispatch the chosen intake's beacon flashes, and a surge enters there if the supply provides one. A flash with nothing behind it is the empty flash, a readable state of its own: the beacon flashes on the cadence, no bodies come, and the forecast shows the next slot. The Collector's gates decide supply (Districts, the Collector). Only the panel selects intake; powering a beacon by any other means, including a coil, lights it but never makes it flash.
• After entry, in one order (R1). Every body resolves the first line that applies: 0, stunned (inside the eight-second stun, and it conducts); 1, pursuit (the surveyor is within its pursuit range: chase, and drift back when out of range); 2, a role target other than light (the Floater's is the flow while water flows; the Anchor's the lowest wet ground; the Carrier's the nearest reachable loose charge; the Grounder's the nearest reachable powered run); 3, attraction (walk continuously to the nearest lit beacon it can reach; hold on arrival; never leave a held beacon for a farther one; retarget to a nearer reachable lit beacon when its own goes dark); 4, spread (no lit beacon reachable: press outward along the entry branch). Pursuit outranks attraction, which is why harvesting inside a held crowd costs health; role targets sit below pursuit and above attraction, so up close every body is just a body. (Owner: Combat Rules.)
• Press (R2). A crowd holding at a beacon occupies a radius set by its size; when bodies join, the radius grows over a few seconds, and when bodies leave or die it shrinks. Press is that relaxation seen from outside, not an unbounded creep. A crowd with no beacon has no centre and spreads along its branch, which is the dangerous case. The forecast overlay draws one ring per crowd. The pumping district's tuning bound, that the first surge's press must not reach the causeway head before the evacuation window closes, becomes checkable: the first surge's radius must be shorter than the causeway.
• What is a beacon. The district's dispatch beacons, the portable beacon, and a moving beacon where a district adds one (the Tram Incline's lamp). Every other lamp is an indicator.
• Arrival. A surge is forty to a hundred and forty organisms entering over about half a minute, on the schedule the forecast shows.

Readable signal. Flashing means a dispatch; the thin cable is visibly thin; a crowd's target is the light it walks toward, and its ring is drawn.

4. Charge: once per organism, ten per battery

• Organisms carry charge and shed it once per expedition; an unshed body glows and a shed body does not, and that is all glow says (R4). A kill drops a small mote of one unit. A stun in water sheds one large mote of five units per ten organisms stunned. Motes fade in seconds.
• A battery holds ten units. Collection goes by a priority the player sets at a shelter (D023, E3): batteries are ordered in a visible list, the first eligible battery fills before the next, unlinked storage included; a large mote is five successive units split across batteries as needed, and only the excess is lost; a full, planted or active-arc battery is ineligible; with no eligible battery the charge is lost. The list cannot be reordered in the field. This replaces the most-room rule, so a player readies one action on purpose instead of splitting charge by accident.
• A Carrier that reaches a mote on the ground takes it and carries it; killing that Carrier drops it again (R5). Nothing but the surveyor and a Carrier can take a mote.
• A coil discharge needs a full linked battery and spends it. It energises the water the surveyor is touching for two seconds (R3, ruled): long enough that an uninsulated discharge costs two health, short enough that the surveyor can collect inside the water during the eight-second stun without insulation being compulsory. Stunned bodies that have already shed yield nothing; stunning again buys control, not charge.
• The arc drains a full linked battery over about ten seconds, one burst per battery; a body hit while the burst runs is chained and the hit conducts onward to bodies within a short reach of it, body to body; the chain does not travel through energised water (R10 declined for this draft; the bounded model preserves spatial limits, and R10 is recorded as the alternative). The burst returns no motes from bodies that have shed. Starting a burst reserves its battery until it ends; an interrupted burst discards the unused fuel. The Glossary's "about twenty seconds" is wrong and is the editor's to fix; ten is the number.
• A Spark killed in water energises that water for two seconds, the same window as a discharge; conducting bodies in it that have not shed are stunned and shed by the ordinary rule, an uninsulated surveyor in it is hurt, and nothing is chained or killed by it.
• Charge never leaves a district with the player; charge left in a battery at extraction is lost at the dock. What a district's own machines meter or move is that district's design.
• Accounting, on every written expedition: dropped, collected, stored, spent, and lost, with lost annotated as fade, overflow, leakage, interruption or dock. (E6; "expired" in the Design Document's ledgers means lost.)

5. The rack

• Eight cells, two rows of four, from the campaign's start (D023, E1). One module or one bundle per cell; the coil takes two orthogonally adjacent cells; the cutter sits outside the rack in the primary cradle, and an alternative primary uses that cradle and one cell for its brace; one primary at a time; any number of batteries, at most one of each other module. There is no rack expansion; the Campaign page's third row and its crane parts are withdrawn in that form.
• Each battery links to one module and each module accepts one link; links may cross any cells. Arrangement, links, primary, cell order for pickups and collection priority are set only at shelters; in the field the surveyor uses what is fitted, may drop a bundle or an inert find at their feet, and may not shuffle cells (E4, E5). Planting a beacon places its battery with it and frees two cells; retrieval is a deliberate interaction that needs two free cells.
• Starting issue: the cutter and an empty battery, plus the workshop's starting module where the colony has one. Recorded racks are reissued on revisits only, capped at six issued cells, so first visits keep their discoveries (D023, COL-I2; Colony and Equipment own the boundary).

6. The expedition frame

• Fifteen minutes; three dispatches on the forecast's schedule where the district's relay runs; docks are hard stops for the Flood; extraction banks cargo and loses charge. Nothing decays between expeditions and nothing is charged for departure or return.
• The colony holds one dock dry per district reached, and may support one further dry shelter at a surveyed compatible connection while its one advanced service is assigned there (COL-I1; Colony owns the service, Districts the connections). Changing the held dock is a one-time refit, not a recurring payment.
• The baseline return is by gravity and dry ground: a gravity-drained dock and a dry route home exist in every district and at the refuge and survive any power shutdown (COL-I4, section 9). Powered conveniences go dormant without supply; banked progress never does.
• A district may change the schedule's shape (the Tidal Barrier adds the tide) but not the frame.

7. What a district may add, and the shared-rule diff it must publish

A district page states, in one short table, what it adds (a device, a way to change topology, an enemy role, a module, a second clock), what it changes (ideally nothing), the signal that announces each addition, and the choice each improves. The test the critic applies: a written expedition in that district whose choices could not occur in another. Additions adopted so far: locks and basin levels; a powered rail and a moving beacon; the Exchange's bank; the Collector's gates and the empty flash; the tide; and eight enemy roles on the merged roster (Walker, Floater, Heavy, Carrier, Anchor, Crust, Spark, Grounder), each with a precedence line and a signal, owned by Combat with the Floater transferred there from the Campaign page. Additions that fail: anything that makes a lamp draw, a coil select intake, an organism shed twice, or a device work without current.

8. Readable state

Steady means powered, flashing means a dispatch, dark means unpowered; the empty flash is a flash with no bodies behind it and the forecast still counting. Wet and dry read by tint and by a second, non-colour channel (proposed: surface motion on wet ground; energised water already reads by its arcs). Glow carries one bit, charge to shed or not; enemy roles read by silhouette and attitude, never by tint or brightness alone (R4; this corrects r2's "size and tint"). The dispatch flash is a slow pulse of about one to two per second; arcs are local sparks along edges, never a whole-screen flash (REF106). Each crowd's ring and each body's current target are drawn on the forecast overlay.

9. Power and dispatch: the state table (Lead with World; the world designer corrects the fiction, this page the rules)

PMR004 asks for one compact table that keeps six things apart. Every row is provisional under D024's Answer A.

Stop, and the baseline return. Setting the head-works to Stop ends the harvest. The store drains and each district's circuit dies in turn, starting at the head-works, within the expeditions that follow (proposal: one district per expedition, nearest the head-works first, shown on the refuge's board); powered doors, hatches, lifts and the colony's powered pump go dormant; gravity drains, dry docks, the culvert and every hand-worked lock and valve keep working, so every district and the refuge still have a dry way home and nothing banked is lost. The relay drums keep turning on flow, so timing survives Stop; supply does not, because the Collector's wheels stop cycling the Flood without the harvest that drives its gates, which is the campaign-scale version of the relay-room choice. The Collector's water-level consequence under Stop is CAM101's to reconcile between its two pages.

10. Rule ownership, and the dispositions this revision makes

Bookkeeping

Sources read for r3. PM Reviews PMR004 ed0def and PMU005 e8c3d4; Brief 70b6b1 (D022 to D024); Tasks 9569fc; Expansion Brief d97965; Design Index 0ee6d3; Combat Rules r2 1126c3 and Enemies r3 0822dd with the role pages; Inventory and Charge r1 73eb77, Equipment a44990, Build Paths a9a288; Colony r1 a1046d; Districts r2 acb797, the Collector 40f2b5, the Head-works 6bf2a7; World and Mystery r20 7699de; Design Review REV104 r1 80a882; Reference REF108 (drainage engineering, index 454f11).

PM report. Task: the Lead's integration of PMR004 1 and 2 into the shared rule contract; artifact: this page r3 (r2 69024c and earlier in history). Changed decisions: none canonical; D023 and D024 embodied as provisional rules; the lead's dispositions of R1 to R10, E1 to E8, C1 to C8 and COL-I1 to I6 recorded in section 10. Evidence: written design against the cited revisions; no player data; nothing built. Risks: the state table's Stop cadence and the fixed-power fiction are the lead's proposals for World to correct; the two-second window and bounded arc are reversible rulings with their alternatives recorded; the Design Document's ledgers were derived under the old rules and are not re-certified. Next handoff: World to correct section 9's fiction and adopt the dispatch sentence on its page; Combat and Equipment to publish the joint effect table with these numbers and fix Encounters A and B as PMR004 asks; the critic on this revision and the Campaign page's r2; the editor's transfer when the role resumes.