#Design Notes — Why It Was Designed This Way

Contents

GM-only deep dive. This document organizes the supplement's design intent and boundaries. If players read it, the surprises lose force. If the GM does not read it, the campaign will drift in the wrong direction.

Core References

- Required: 9 Basic Axiom Principles · 10th-dan Renown Titles

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#Design Philosophy

#1. Keep The Dual Scent/Law Structure In The Supplement

Among the core's 9 axioms, the dual Scent/Law structure remains unchanged in this supplement. Every new rule(Barrier HP, core economy, morale, Spirit Realm Exposure) must be reflected in both numbers and narrative.

• Barrier HP 75 → not just a number, but "the Barrier sways as if about to collapse, and the onmyoji's back bends a little"
• 5 cores → "dark red beads vibrate low inside brass jars in the storehouse"
• resident morale 3 → "children do not play. Even when the bell rings, no one comes out."

Numbers are tools; narrative is the purpose.

#2. Adventure Path Style — Each Chapter's Independence

The lesson from Paizo's Adventure Path: even if one chapter is missed, the next chapter must remain playable. Linear causality creates story, but the ability to leave creates freedom.

• Each chapter's clues and rewards only "work in favor of" the next chapter; they are not required premises
• Even if the party misses the seal records in Chapter 3, they can rediscover them through another route in Chapter 5
• If Chapter 4 is skipped, Chapter 5 difficulty increases by only +1 grade; failure is not forced

#3. Starting At 1st Dan — Let The Weight Of Growth Be Felt Fully

Starting with high-dan PCs makes this "a hero's mission." Starting at 1st dan makes it "the miracle of survivors." While 1st-dan PCs grow into 9th-dan masters, the domain's residents, retainers, and lord also grow, wear down, and face death.

This is not a repeat of the core introduction. If the introduction is "learning how to use these rules," this supplement's 1st dan is "learning how to survive in this world."

#4. A Small Domain — Density Of Meaning

In a great domain, one lost resident is a statistic. In a small domain, one name, one family, one empty seat. 800 is an intentional number. It is a scale where every resident the PCs meet throughout the session can have a name.

#5. Buddhist Hell Motifs — Karma, Not Evil

The Spirit Realm of this supplement is not a good-versus-evil dualism. Hell is not punishment; it is a mirror. Yoma are enemies, but they may once have been human, or be condensations of particular attachments, or be the lingering scent of those who vanished.

Devices that prevent players from reading "hell = evil" too easily:

• At least one negotiable yoma exists in every chapter
• "Good uses" of the 5 hell schools are specified
• 4 yoma partners are available for romance
• The previous drifters of Chapter 4 — they were once you

#6. Redefine Victory

The core can operate at a scale where "saving the world" is possible. In this supplement, "saving the domain" can be a victory even if only 600 of 800 people survive. Not annihilation, but choice, is the narrative climax.

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#Grounds For Design Decisions

#D1. Why PCs Start At 1st Dan

"A small rural domain fell into the Spirit Realm; there is no way it has 5 10th-dan Tatsujin." — simple plausibility.

Only 1 high-dan onmyoji is exceptional, and the background that he was in this domain because he was retired also fits. All other PCs are 1st~3rd-dan local samurai, residents, or drifters.

Side effect: 1st-dan growth pace must be managed. 2 dan per chapter = 1→9 dan over 20 sessions. This matches the core pace.

#D2. Choosing A Kokunin Lord

• Hatamoto: the "cut off from the main house" theme is good, but the very existence of a main house invites "reinforcements may come," weakening tension
• Tozama daimyo: the status-qualification test is good, but clashes with the "small countryside" tone
• Kokunin: local landed clan. No main house. Generational ties to residents. No reinforcements possible. Maximum tension.

#D3. The Onmyoji's Burden On Two Axes At Once

• Core economy only: resource-management game. Weak drama.
• Life depletion only: strong drama, but no resource management.
• Both axes at once: the basic loop is core economy; at extremes, life depletion. Resource + drama.

#D4. Authenticity Of The Buddhist Hell Motifs

To avoid using hell only as "dungeon backdrop":

• Include the doctrinal essence of each hell in the GM guide (03-06)
• Maintain the premise that the suffering of hell is "a reflection of karma"
• Place Avici Hell as the final chapter — endless suffering becomes the moment of choice

#D5. Independent Version Management

Protect the stability of core Canon. Prevent this supplement's experimental rules from leaking into the core.

→ Separate wiki/ex1/VERSION. Not linked from the core index.

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#Boundaries Of Play Burden

#Recommended Maximum Burden

If pushed to extremes, this supplement can exhaust both GM and players. The following boundaries are recommended.

#Scenes Requiring Care

The following scenes require prior table agreement:

• Death of resident children (exists in open-world and side scenarios)
• Bereavement or separation from romance NPCs (tragic branches during endings)
• Death of the onmyoji Gensho (possible in extreme endings)
• Heart corruption of Lord Akihisa (possible in the worst ending)
• Mass resident deaths (Barrier collapse ending)

Introducing safety tools such as an "X card" in Session 0 is recommended.

#Things To Avoid

• "Heroic victory" tone: that is not what this supplement is about.
• Unconditional happy ending: none of the 3 branch endings is a complete happy ending.
• PCs showing off high dan: the core reward of the supplement is the sense of achievement when PCs who began at 1st dan reach 9th dan.
• Using the onmyoji as an "infinite support NPC": he is a ticking time bomb. It succeeds when players start seeing him as a resource that gets spent down.

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#Ending Design Principles

#Balance Of The 3 Branches

All three endings have a structure of gaining something and losing something. There is no perfect victory.

#Collision With 10th-Dan Renown Titles

Core Renown Titles are campaign-ending devices. When a Renown Title is gained, Domination, Breakthrough, Core Zone, and the Energy economy can be invalidated. This supplement's Chapter 5 ending mechanisms(Barrier, cores, onmyoji) may become useless before Renown Titles.

Design boundaries:

• Reaching a 10th-dan Renown Title is allowed only immediately before Chapter 5 Act 4(climax)
• Reach the ending within 1~2 sessions after gaining a Renown Title
• 2 or more 10th-dan PCs in the party: the GM accelerates the ending (to prevent Renown Titles from feeling flat)
• The "Transformation" ending is open only to characters who have not gained a 10th-dan Renown Title — those who have gained one can only return or settle

#Required Conditions For Each Branch

Return Ending:

• seal records(Chapter 3 clue) or 3 or more alternate clues
• onmyoji survives or a successor is designated
• face the sealing stone in Chapter 5 Act 4 climax

Settlement Ending:

• secure a foundation for domain self-sufficiency inside the Spirit Realm (core economy automation or hell school transmission)
• resident morale 5 or higher
• Akihisa accepts transformation of his kokunin identity (renaming himself as "lord of the Spirit Realm")

Transformation Ending:

• at least 1 PC voluntarily chooses transformation
• contract relationship established with an intelligent Spirit Realm being (possible in Chapters 2 and 4)
• the transforming PC has not reached 10th dan

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#Compatibility Boundaries With The Core

#What Can Contribute To The Core

Possible candidates from this supplement that could flow back into the core:

• Romance system → can move to a core expansion option
• More detailed domain management → expansion of core domain management
• Interesting hell schools → consider promotion into core schools

However, do not modify the core during this supplement's development period. Use a separate proposal process after stabilization.

#What Must Not Affect The Core

• Barrier HP / core economy: unique to this supplement
• Detailed causality of the Enmadoji Seal: the core should only contain hints
• Mugen Path(10th-dan school): risk of collision with the core Renown Title system

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#GM Operation Checklist

• Are Scent and Law both alive?
• Can each new rule be found immediately in its corresponding body document?
• Do tables, links, and terms avoid conflict with core Canon?
• Is the 10th-dan Renown Title being used only as a closing device immediately before the Chapter 5 climax?
• Are there no immediately visible contradictions within the same file or between adjacent files?

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"Design is not a wall, but a skeleton. Play puts flesh on it."