#Castle Structure Rulings — Structure Conversion Cards

Contents

Data Catalog. This document is a lookup dictionary — a catalog that fixes structures such as castle gates, moats, watchtowers, and honmaru as existing gimmicks in co. Every card follows the 4 steps of the 02-01 conversion procedure — this is only the reference dictionary for that procedure, not a new rule set. No new numbers: every value on the cards is taken directly from co.

#Scent — Same Stone, Split Uses

Castle gates were raised to block, watchtowers to see, and wells dug to live.

Yet the same stone is an obstacle to the besieger, a lifeline to the defender, a shadow to the infiltrator, and a tomb to the one walking through ruins. This dictionary places those four faces on one card — one structure, one or two co gimmicks, and four lines of mode hooks.

#How to Read — The Card's 5 Fields and Conversion Rules

Each card fills five slots (as in 02-01 §Format):

Structure Name (Kanji)
├ Scene Function : 1~2 of the seven questions in 02-01 §Law 1
├ Zone Property : co gimmick from the 02-01 §Law 2 dictionary (quoted as written — link)
├ Scene Pressure : the mode-specific items turned on among the pressures in 02-01 §Law 3
└ GM Hook    : siege / defense / Infiltration / ruins — one line each

No new stat system. Fortress Defense uses palisade 12 / stone castle 15 / great castle 18 from co-03-10 as written, and gimmicks quote only the gimmick names from co-05-05. A card only decides "which co gimmick is this structure," and does not redefine that gimmick's numbers. Ranged shooting is Archery (covering bows and teppo; no separate gun skill), time is rounds, and durability is Wounds.

#A. Blocking and Breakthrough Structures — Gates, Walls, Moats

The castle's outer line exists to block. Three structures support the pressure of siege and defense.

#Otemon and Castle Gate (大手門)

Otemon and Castle Gate (大手門 / 搦手門)
├ Scene Function : blocks · gathers troops · connects to the Core Zone
├ Zone Property : narrow path(cap 3~4, Blockade Breakthrough 2d10+Courage ≥ 15) + wall/barricade(door leaves, palisade)
├ Scene Pressure : time · morale · (siege)fire
└ GM Hook    : 4 modes ↓

Zone Property Detail. The gate passage is a narrow path — the side that reaches it Blockades, and the opposing side can force through only with Blockade Breakthrough (2d10+Courage ≥ 15). Door leaves and palisades are wall/barricade (movement +2 Energy, durability 3). The gate's own hardness is the fortress Defense grade (co-03-10: palisade 12 / stone castle 15 / great castle 18) — the Target Number for squad volley fire and forced charge is this value.
The masugata (枡形) trap yard is expressed by layering another narrow path one passage behind the first, making a 2-stage Blockade where enemies trapped inside the gate are flanked from above (watchtower). This is not a new rule — it is narrow path + high ground stacked.
Example Maps. co-05-06 03 castle gate pressure battle (narrow path cap 4 + barricade + high ground on the castle wall) and 21 fortress counterattack (reverse direction, pushing from inside to outside).

Mode	GM Hook
siege	Hammer the main gate — to break a Blockaded narrow path, cut down defenders or risk a bloody Blockade Breakthrough. Clearing the wall top first is standard.
defense	Close every gate — place Blockaders and draw enemies into the masugata for a pincer attack.
Infiltration	Target the karametemon (rear gate) — bypass the narrow path through a side gate or collusion instead of the main gate.
ruins	Broken door leaves are a collapsed barricade (durability 0) — what once blocked now opens the road.

#Wall, Earthwork, Stonework (土塁·石垣)

Wall, Earthwork, Stonework (塀·土塁·石垣)
├ Scene Function : blocks · gives height
├ Zone Property : wall/barricade + high ground(shooter on stonework) + (on collapse)rockfall/collapse
├ Scene Pressure : time · (siege)fire
└ GM Hook    : 4 modes ↓

Zone Property Detail. Banks and walls are wall/barricade separating two zones (movement +2 Energy, Defense +1 when taking cover), and the top is high ground (ranged +2, enemy melee -1). A collapsing wall converts to rockfall/collapse or a collapsed wall gap (co-05-06 13 gap in the collapsed wall = standard melee-chaos Core Zone).
Detailed handling of fire attack and collapse (triggers and Wounds damage) is delegated to 02-03 siege hazards — this card only decides "which gimmick is it" (no duplication).

Mode	GM Hook
siege	Trapped below the bank, looking up — neutralize high ground with ladders or fire, or break the wall open and create a gap (Core Zone).
defense	Ranged advantage from shooters on the stonework — the bank itself is the defense line.
Infiltration	Cross the wall through an earthwork gap or drainage hole (Infiltration check, no combat).
ruins	Collapsed stonework is a rockfall zone — every step risks giving way.

#Moat (堀)

Moat (堀 / 水堀·空堀)
├ Scene Function : blocks · forces Approach
├ Zone Property : underwater/waterside(water moat) or narrow path variant(dry moat)
├ Scene Pressure : time(detour search)
└ GM Hook    : 4 modes ↓

Zone Property Detail. A water-filled water moat (水堀) is underwater/waterside (movement +1 Energy, mounted movement impossible, fire attack impossible). A dry empty moat (空堀) is treated as a narrow path variant whose width narrows the Approach route into one line.
The moat traps attackers below — pair it with wall-top high ground to complete the bank-moat pressure as one body.

Mode	GM Hook
siege	Fill it, cross it, or detour — ford through while accepting underwater +1 Energy, under time pressure.
defense	The moat forces Approach into one line — the route for concentrated shooting is fixed.
Infiltration	The moat becomes an Outside Zone entry axis candidate (swimming/diving) — a shadow road to the rear gate.
ruins	Debris and bones piled on the dry moat floor — the empty moat becomes a narrow passage.

#B. Sightline and Command Structures — Watchtower, Honmaru, Kuruwa

Seeing and governing. Height and hierarchy decide the texture of the fight.

#Watchtower (櫓)

Watchtower (櫓, yagura)
├ Scene Function : gives height · sightline · signal
├ Zone Property : high ground(ranged +2, enemy melee -1, entry +1 Energy)
├ Scene Pressure : morale(signal/Command)
└ GM Hook    : 4 modes ↓

Zone Property Detail. Watchtowers and wall tops are high ground — ranged +2 in this zone, enemy melee -1, entry +1 Energy (free for Lightness Skill Licensed or higher). Ranged checks use Archery (one skill covers bow and teppo; write "Archery (teppo)" only when the weapon distinction matters — no separate gun skill exists).
Example Map. The wall top in co-05-06 03 castle gate pressure battle — the side holding the watchtower gives shooting support to the whole Front Zone.

Mode	GM Hook
siege	If the watchtower is not cleared, castle gate Breakthrough efficiency drops sharply — neutralize high ground first.
defense	Put teppo and archers in the watchtower to support the Front Zone with fire.
Infiltration	Sleeping watchtower — a lax guard hour, foothold for Infiltration.
ruins	Collapsed watchtower — once sightline, now falling danger ("collapsing tower" variant).

#Honmaru (本丸)

Honmaru (本丸)
├ Scene Function : connects to the Core Zone · Command
├ Zone Property : Core Zone type 3 — boss residence(automatic Wounds recovery every round while the castle lord remains)
├ Scene Pressure : morale(Command core) · time
└ GM Hook    : 4 modes ↓

Zone Property Detail. The innermost kuruwa is Core Zone type 3 boss residence — while the castle lord or commander is here, they automatically recover 1~2 Wounds every round (power of the throne). Frontal attack alone does not end it, so the PCs must draw them out (wildlander shove, feng shui master forced movement, samurai duel provocation) or cut off the recovery source first (drawing into the Core Zone). The tenshu is a tower of residence and authority, not the final battlefield, so use the honmaru itself as the Core Zone and leave the tenshu as description inside it.

Mode	GM Hook
siege	Final Breakthrough objective — break each layer of kuruwa and draw the boss from the throne.
defense	Final line of resistance — if this is breached, it is over. The place after every retreat line is spent.
Infiltration	Bypass the layers and go straight to the Core Zone — shinobi Shadow Crossing or a secret passage bursts into the honmaru.
ruins	Earthbound spirit's throne — the place where the dead castle lord could not leave; boss residence becomes a ghost battle as written.

#Kuruwa — Ninomaru and Sannomaru (二の丸·三の丸)

Kuruwa (二の丸·三の丸, kuruwa)
├ Scene Function : blocks(multiple defense lines) · retreat line
├ Zone Property : multiple-zone chain + candidate conditional Core Zone(type 6)
├ Scene Pressure : time(layered retreat)
└ GM Hook    : 4 modes ↓

Zone Property Detail. The second and third kuruwa are the logic of layers as written — when one layer is breached, defenders fall back one layer inward and stand again (chain of multiple zones). The inner yard after the gate is breached can convert into Core Zone type 6 conditional Core Zone (if both sides' Domination rises at once, deadlock → melee chaos).

Mode	GM Hook
siege	Each breached layer leads to the next — a time-draining battle stretched by layers.
defense	Retreat-line resource — when pressed, fall back to the inner kuruwa and rebuild the front.
Infiltration	Side doors between kuruwa become a zone-skipping route.
ruins	Empty kuruwa — collapsed walls and vacant residences become a maze.

#C. Resource and Faith Structures — Well, Storehouse, Shrine

A castle falls first to thirst and hunger, before blades. Three structures support the resource game of holdout and Infiltration.

#Well (井戸)

Well (井戸 / 水の手)
├ Scene Function : protects supply
├ Zone Property : Core Zone type 2 — objective point(maintain Domination for 3 rounds) + holdout resource
├ Scene Pressure : supply · Popular Support(on poisoning/contamination)
└ GM Hook    : 4 modes ↓

Zone Property Detail. The lifeline of a holdout is Core Zone type 2 objective point — the side that maintains Domination for 3 consecutive rounds takes it. If it dries or is fouled, the castle collapses from within, so it is the core of supply pressure (linked to the 04-02 holdout clock).
Example Map. co-05-06 16 twin-well Core Zone — an example with a dry well (standard melee chaos) and blood-water well (Spiritual Taint) as multiple Core Zones.

Mode	GM Hook
siege	Cut the water source — block or foul the well and collapse the holdout from within.
defense	Drying/contaminating resource clock — defending the well is buying time.
Infiltration	Poison insertion objective — one silent move that breaks the castle from inside.
ruins	Blood-water well — the contaminated source becomes a Spiritual Taint Core Zone.

#Storehouse (蔵)

Storehouse (蔵 / 兵糧庫·火薬庫)
├ Scene Function : protects supply · gathers
├ Zone Property : supply depot(reload/replenish on lull) + gunpowder storehouse as fire zone/explosion variant
├ Scene Pressure : supply · (on fire attack)time
└ GM Hook    : 4 modes ↓

Zone Property Detail. The grain storehouse is a supply depot — the occupying side reloads all teppo + replenishes 1 consumable during a lull (destroyed by 2 enemy attacks). The gunpowder storehouse is a "gunpowder supply depot" variant that spreads into a fire zone (1 Wounds every lull) when destroyed.

Mode	GM Hook
siege	Arson objective — burning the storehouse breaks the holdout's supply line.
defense	The heart of a long battle endured around a supply depot.
Infiltration	Steal or destroy gunpowder — one spark shakes the castle from within.
ruins	Empty storehouse or burst gunpowder storehouse site — remains of a scorched fire zone.

#Shrine and Small Shrine (神社·祠)

Shrine and Small Shrine (神社·祠, tutelary shrine)
├ Scene Function : connects to the Core Zone · taboo
├ Zone Property : Barrier(block yoma · Fear immunity) + spirit-vein + Spiritual Taint when seal breaks
├ Scene Pressure : yoma · Spirit Realm
└ GM Hook    : 4 modes ↓

Zone Property Detail. A tutelary shrine guarding the castle is Barrier (2 Wounds or Wisdom ≥ 11 when yoma enters, allied Fear immunity and Spiritual Taint nullification inside the Barrier, upkeep 1 Energy/lull) + spirit-vein (recover 1 additional Wounds during lull). If the seal breaks, it flips into Spiritual Taint (Mental Save Courage ≥ 11 every lull). Spirit Realm elements are self-contained with only co gimmicks — no separate module (ex/fc08) is assumed.
Example Maps. co-05-06 04 stair battle (Barrier before the temple gate) and 19 mountain temple defense (inside the dharma hall = objective point + Barrier, bell tower = high ground).

Mode	GM Hook
siege	Yoma troops cannot enter unless the Barrier is broken — target the ritualist or ritual implement first.
defense	The Barrier is the final line blocking yoma — someone must bear the upkeep (1 Energy/lull).
Infiltration	Sacred-ground taboo — step carelessly and take impurity (narrative constraint).
ruins	Sealed shadow gate — the broken Barrier site becomes the source of Spiritual Taint.

#D. Stealth Structures — Secret Passage and Castle Town

Two structures for Infiltration mode, which reads the castle's promise backward.

#Secret Passage (抜け穴)

Secret Passage, Sewer, Cliff (抜け穴)
├ Scene Function : hides · connects to the Core Zone(bypass)
├ Zone Property : Outside Zone(normal movement impossible; only shinobi, Infiltration Master, Lightness Skill Saint can enter) + narrow interior variant
├ Scene Pressure : collusion · time
└ GM Hook    : 4 modes ↓

Zone Property Detail. A secret passage is an Outside Zone — normal movement impossible; only shinobi (Shadow Crossing 0 Energy), Infiltration Master (4 points, 2 Energy), and Lightness Skill Saint (5 points) can enter. The Outside Zone has no Domination concept, and no new Infiltration check is needed ([36-skill Infiltration and Perception] are enough). The inside of a narrow passage is narrow interior (short weapons -1 Energy, Infiltration +2, mounted entry impossible).
Example Map. co-05-06 26 raid on enemy headquarters (Outside Zone type 3 enemy headquarters — bypass axis for decapitation battle).

Mode	GM Hook
siege	Rear gate opened by a collaborator — if the bar is lifted from inside, the narrow path Blockade collapses.
defense	Escape and relief-force passage — the final breathing route under siege.
Infiltration	Main entry route — skip kuruwa through the Outside Zone and burst straight into the honmaru (Core Zone).
ruins	Discovery of a forgotten passage — the ruined castle's secret opens a new road.

#Castle-Town Contact Point (城下町)

Castle-Town Contact Point (城下町)
├ Scene Function : gathers troops/information
├ Zone Property : social/information zone(not a combat gimmick) — narrow interior(alley)·forest/thicket during Infiltration
├ Scene Pressure : Popular Support
└ GM Hook    : 4 modes ↓

Zone Property Detail. The town below the castle is not a combat zone, but a social zone — the stage for rumors, Negotiation, and information. Do not force it into a battlemap. Only during Infiltration prep scenes, treat alleys as narrow interior and outskirts as forest/thicket. Checks are Negotiation, Infiltration, and Perception (36 skills). Popular Support follows co-03-10: ≥7 gives militia squad +1, ≤2 gives allied squad Cohesion -1.

Mode	GM Hook
siege	Pressing the castle town shakes supply and Popular Support — preparatory work for a siege.
defense	Popular Support becomes militia — ≥7 gives squad +1, ≤2 gives Cohesion -1.
Infiltration	Infiltration prep scene — hear rumors, recruit a collaborator, learn the alleys.
ruins	Abandoned castle town — an urban area with only empty alleys and drifting rumors.

#Mapping Overview (Quick Reference Seed)

Lookup table used directly by 99-01 quick reference. No number column — only gimmick names, map numbers, and co references.

Structure	Scene Function	1st Zone Property	Support Gimmick	Example Map
otemon and castle gate	blocks · gathers · connects	`narrow path`	wall/barricade · (Defense `co-03-10`)	03 · 21
wall, earthwork, stonework	blocks · height	`wall/barricade`	high ground · rockfall/collapse	13
moat	blocks · forces Approach	`underwater/waterside`	narrow path (empty moat)	—
watchtower	height · sightline · signal	`high ground`	—	03
honmaru	connects to Core Zone · Command	`Core Zone type 3`	—	—
kuruwa	blocks · retreat line	multiple-zone chain	`conditional Core Zone (type 6)`	—
well	protects supply	`Core Zone type 2`	holdout resource	16
storehouse	supply · gathers	`supply depot`	fire zone (gunpowder storehouse)	—
shrine and small shrine	connects to Core Zone · taboo	`Barrier`	spirit-vein · Spiritual Taint	04 · 19
secret passage	hides · bypasses	`Outside Zone`	narrow interior	26
castle town	gathers troops/information	social/information zone	narrow interior (alley) · forest	—

#Compression Rule Recheck (02-01 §Law 4)

Do not draw one castle as one map. Keep only the 3~7 zones important to today's scene, and mix structures with different purposes (castle gate, watchtower, inner yard, well, storehouse, secret passage). Do not draw new example maps; vary 03·19·21 from co-05-06. The fact that cards break structures apart individually does not mean all of them should be placed on one map — cards are a dictionary, and one battlefield meal is a spread chosen from that dictionary.

"Giving four names to the same stone — that is all this dictionary does."