#Scene-Based Siege Procedure — Opening a Castle in Ten Scenes

Contents

Scene Tool. This is the procedure tool paired with the 03-01 siege guide. If the guide is the flow of "what the attacking side prepares and how it applies pressure," this document is the GM tool for cutting that flow into session-play scene units. Every structure ruling follows 02-01 and 02-02, and does not redefine them.

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#Scent — A Castle Does Not Fall in One Day

A siege is long.

Only after many days, many attempts, and many small fights pile up does the castle gate open. A castle does not collapse through one giant battle table — today scouts are sent out, the next day a supply road is cut, and after that the shooters on the wall are worn down. Siege is not one large fight, but the accumulation of small scenes.

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#Law 1 — Why Cut It into Scenes?

co combat is zone combat that draws only 3~7 zones at a time (co-05-01). A wargame that places the entire castle on one map conflicts with the identity of co and fc — the story of a hero's blade striking one point becomes blurred across the board of tens of thousands of troops.

So siege is cut into scenes. A scene has three things:

1. One small map — 3~7 zones taken from co-05-06 30 battle maps.
2. A clear victory condition — what ends this scene.
3. Pressure passed to the next scene — time, supply, and morale move by ±.

A session usually handles 1~3 scenes. This document is not a new numerical system, but a scene progression device — every check and number is cited from co.

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#Law 2 — 10 Scene Cards

The 10 scenes are collected in one place as cards. 03-01 and 07 Kageyama Castle weave and cite these cards in flow order. Each card = scene question / recommended battle map / core check / victory-failure / next scene.

#① Reconnaissance (偵察)

Scene question : Where is the castle weak?
Recommended battle map : co-05-06 #02 mountain-road ambush · #07 bamboo grove detour (using the outer perimeter)
Core check : Perception · Infiltration · Archery(scouting) — odd Target Number
Victory/failure : success=weak point and guard-shift time secured / failure=penalty carried into night attack or gate pressure
Next scene : success → weak point choice(blockade/gate/collusion) / failure → blind gamble

#② Blockade (遮斷)

Scene question : Can the castle be starved?
Recommended battle map : co-05-06 #01 blockade on the bridge(narrow path cap 3) · #23 supply convoy battle(attacking side raid)
Core check : narrow path Blockade / Blockade Breakthrough 2d10+Courage ≥ 15 (co-05-03)
Victory/failure : success=defender holdout clock accelerates / failure=reinforcements·supplies arrive
Next scene : success → negotiation possible through morale and time pressure / failure → frontal gate pressure

#③ Gate Pressure (城門 壓迫)

Scene question : Can the main gate be forced?
Recommended battle map : co-05-06 #03 castle gate pressure battle · #21 fortress counterattack(reverse direction)
Core check : narrow path · wall/barricade · high ground (co-05-05) / Breakthrough 11·13·15 (co-05-03)
Victory/failure : success=entry inside the gate / failure=vulnerable·knocked back, morale -
Next scene : neutralizing shooters on the wall comes first — if insufficient, return to pressure(③)

#④ Fire Attack (火攻)

Scene question : What will be burned?
Recommended battle map : co-05-06 #15 burning cart train · #20 harbor warehouse battle (fire zone spreads)
Core check : strategy·Infiltration(ignition) or Archery(fire arrows) — effect follows the 02-03 fire attack card
Victory/failure : success=supply and morale hit together / failure=headwind·allied burning
Next scene : success → blockade and negotiation pressure increase / failure → retry after firefighting

#⑤ Night Attack (夜襲)

Scene question : Can darkness be ridden?
Recommended battle map : co-05-06 #26 enemy headquarters night raid(Outside Zone) · #08 night-market alley(darkness)
Core check : outer perimeter entry ambush +2 / Outside Zone entry enhanced ambush(+2·no reaction) (co-03-06)
Victory/failure : success=guard blind spot pierced / failure=discovered, immediately shifts to frontal siege
Next scene : success → collusion·direct honmaru route / failure → gate pressure(③)

#⑥ Negotiation (協商)

Scene question : Can the gate be opened without a sword?
Recommended battle map : none — social scene (negotiation·strategy checks centered)
Core check : negotiation · strategy — public sentiment and cohesion linkage (co-03-10)
Victory/failure : success=open castle·surrender·internal response / failure=breakdown, time spent
Next scene : success → skip gate pressure(bloodless entry) / failure → blockade·pressure continues

#⑦ Supply (補給)

Scene question : Do we starve first? (reverse siege clock)
Recommended battle map : co-05-06 #23 supply convoy battle (attacking side escorts)
Core check : supply depot gimmick (co-05-05) / escort squad operation (co-06-06)
Victory/failure : success=siege continues / failure=attacking-side morale pressure increases → withdrawal pressure
Next scene : accumulated failures → morale(⑧) or withdrawal(Law 3)

#⑧ Morale (士氣)

Scene question : Can the besieging force hold?
Recommended battle map : none — lull maintenance scene
Core check : squad cohesion (co-06-06 lull) · Presence aura
Victory/failure : success=cohesion maintained / failure=collapse(cohesion 0)·desertion
Next scene : moral dilemma hook(plunder vs discipline, co-08-01) — the choice divides cohesion

#⑨ Collusion (內通)

Scene question : Can we make allies inside the castle?
Recommended battle map : secret passage entry (02-02 structure card — Outside Zone)
Core check : negotiation · Infiltration · strategy
Victory/failure : success=large bonus to gate pressure and night attack / failure=collaborator removed + search scene(04-01)
Next scene : success → night attack(⑤)·direct honmaru route / failure → defender alert strengthened

#⑩ Barrier Destruction (結界 破壞)

Scene question : Can the castle's spiritual wall be broken?
Recommended battle map : co-05-06 #04 stair battle(Barrier) · #17 red moon ritual site(Barrier·spiritual vein)
Core check : Exorcism · Prayer(spiritual-response class) — Wisdom+Exorcism ≥ 15 (co-08-04)
Victory/failure : success=yoma forces can enter / failure=Barrier maintained(yoma entry 2 Wounds)
Next scene : success → honmaru(source of Spiritual Taint) / failure → directly target caster·ritual implement

Barrier destruction is self-contained with this volume's co Barrier gimmick alone — refer to fc08 (ruins and battlefield yoma) if present, but the alternative when it is absent is co Barrier + GM discretion.

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#Law 3 — Pressure Between Scenes (Clock)

Scene connects to scene through four axes of pressure. Each card's "next scene" moves these axes by ±:

• Time — the longer the siege, the worse for the attacking side (reinforcements and season).
• Supply — the attacking side's food and powder (⑦ supply scene).
• Morale — the attacking side's cohesion (⑧ morale scene).
• Defender clock — meshes with the 04-02 holdout clock.

Pressure is represented as a GM tick clock (not a numerical system), not a d100 probability table. If random events for a long siege are needed, limit them to one d100 (minimal probability-table principle). Clock tick units are fixed by 04-02, and this document follows that unit — the siege clock and holdout clock are two sides of the same clock (siege=attacker pressure, holdout=defender pressure).

Withdrawal is not defeat, but a new scene. If the attacking side cannot endure the clock, bring the co-03-06 battlefield exit procedure (exit cost 3 Energy, pursuit opposed by 2d10+Finesse) up to scenario scale and connect it to a regroup and re-siege scene.

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#Law 4 — Scene Assembly Procedure (GM Workflow)

Four steps to build one session's siege:

1. Choose 1~3 scenes to play today from the 10 types.
2. Pull each scene's recommended map from the 30 maps and fine-tune it with the 02-02 structure cards.
3. Write down each scene's victory/failure conditions and pressure changes in advance.
4. Based on the branch, foreshadow the next session's scene.

When scaling up to a campaign battle. Tie PC missions to co-08-01 encounter design §5 core types of battle situation, and quote the principle from co-06-06 as written: "do not track 5 ten-thousand people — compress it to one zone where the protagonists act." The GM gives the narrative that victory or defeat in one zone divides the whole battle situation.

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#Table Hooks — For the GM

Theme. Siege is both "the story of opening a castle" and "the story of the besieging army not collapsing" — clocks turn both inside and outside.

Scenario Hooks (example scene arrays):

• Fast battle — reconnaissance → night attack → honmaru. Before reinforcements arrive, use the darkness and strike at once.
• Encirclement — blockade → supply → negotiation. A road opened by hunger rather than steel.
• Forced assault — reconnaissance → fire attack → gate pressure. Face the front with fire and ladders.
• Internal response — collusion → Barrier destruction → night attack. With the collaborator inside.

Mode Shift on Failure:

The siege mode in 07 Kageyama Castle presents how these ten scenes are arranged as one sequence.

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"A castle does not fall in one day — it falls after one day's scene has piled up ten times."