#GM Masterwork Weapon Creation Guide

Contents

Scene Tool — custom masterwork creation procedure. This document defines the 7-stage procedure a GM follows when making a custom masterwork weapon within a campaign. It follows the data structure of the body co-07-02 § Masterwork Rule Summary — technique slots, grade, and acquisition principles are all body-standard.

This guide is not a document for inflating powerful rewards. It is a document for matching the reasons of story and data. A single new masterwork should be able to change one scenario's motive and one PC's identity.

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#Opening Fragment — The Masterwork That Does Not Yet Exist

The GM gazed at the empty data fields. The attack name, the curse, the ownership condition — none yet existed. But the first scene already did. On a bridge in the rain, a blade that had lost its master would be set at someone's feet.

"What effect does that blade have?" the player asked.

The GM did not answer at once. "First I have to decide who the owner was. And why it was set on the bridge."

"Then the data comes later?"

"Not later — it follows." The GM wrote a single line above the blank. The scabbard opens only on a rainy day. "Once this line exists, the effect, the curse, and the ownership condition all gain direction."

The masterwork made that day was not the strongest weapon. But the moment it appeared, everyone fell to questioning. Who set this blade down on the rainy bridge and walked away. And why has it not yet dried.

#§ Scent — A New Name Meets the Blade

A blade is forged. From a swordsmith's hand. An ordinary blade goes out to the market as it is, is worn at some samurai's hip, cuts down a hundred, and breaks at some point. But some blade — the very process of its making becomes an anecdote. The last blade a swordsmith forged in his life, or a blade refined upon the spirit vein of a shrine, or a blade forged last before a house's crisis.

That anecdote becomes the blade's name. Once it bears a name — the blade looks for an owner who will carry its anecdote on to the next line. The beginning of a masterwork.

This document's 7 stages are a procedure for writing that name's first line together.

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#§ Law — The 7-Stage Procedure

A GM's 7 stages for making 1 new masterwork.

#Stage 1 — Era Selection

Deciding the era automatically narrows the candidate schools, swordsmiths, and owners. A single masterwork takes its place within a single era. If the era is not decided, the anecdote may contradict itself.

Spirit Realm Wandering Treasure exception: if you want to make a blade that defies its era, follow the co-07-02 § Spirit Realm Wandering Treasures rule. A Spirit Realm Wandering Treasure is a weapon that cannot exist in its native era, and bears the [Spirit Realm Wandering Treasure] tag.

#Stage 2 — Owner Selection

In whose hand this blade was. The owner makes the famed blade's anecdote more than the swordsmith does.

Deciding the owner fixes the blade's active scenario. "In what seat this blade shines most" becomes clear.

#Stage 3 — Weapon Category Selection

Choose a base weapon from the weapon categories of co-07-01-weapon-catalog.md. The base weapon's Attack A / Attack B / Defense techniques become the foundation of the new masterwork.

Era-fit note: the uchigatana is late Muromachi onward. Firearms are Sengoku onward. If the category conflicts with what was decided at era Stage 1 — reclassify it as a Spirit Realm Wandering Treasure, or decide the era again.

#Stage 4 — Anecdote Selection

The one-line anecdote a blade holds. This volume recommends the following seven templates.

A single line of anecdote determines the masterwork technique's effect.

#Stage 5 — Ownership-Condition Selection

Choose one type from fc05-04-01 § The Seven Relationship Types. Or choose a concrete condition from §04-01 § Ownership-Condition Catalog.

Set a condition the PC can fulfill within a scenario. Do not use a condition that is impossible to fulfill in a lifetime.

The intensity of a bloodline condition: a house direct-descendant condition is powerful, but set the reward equally strong for it. For PCs who are not direct descendants, set at least one detour that can be fulfilled by "the house's recognition" (an outside guardian, friendship, indebtedness).

#Stage 6 — Curse / Blessing Selection

Choose from the 7 curse types and 5 blessing types of fc05-04-02-curses-devotions.md. Or author a new curse / blessing.

Curse-authoring check:

• Is it a choice mechanic rather than an automatic punishment?
• Is there a scenario path to recover from the curse?
• Is there no Energy / Wounds confusion?
• Does it not lock down the PC's class signature?

Blessing-authoring check:

• Does it not exceed the average of body masterworks? (+1–2)
• Does it align with the PC's identity?
• Does it not imitate Divine Treasure devotion?

The ratio of curse and blessing: a curse-only masterwork (Kanabo), a blessing-only masterwork (Genji no Yoroi), a masterwork with both (Muramasa, Tengu no Hauchiwa) are all possible. This volume's new masterworks recommend a total of 1–2 curses and blessings per masterwork.

#Stage 7 — Authoring the Masterwork Technique

The masterwork's 5th technique slot. It follows the format of the body co-07-02 § Masterwork Rule Summary.

| Technique | Type | Energy | Check | Effect | Limit |
|------|------|------|------|------|------|
| **[masterwork] technique name (kanji)** | Kata or Attack | 2–5 | 2d10+(attribute)+(skill)+(bonus) >= Defense | (damage / status effect) | 1 per round / 1 per combat / 1 per session |

Authoring one line of a masterwork technique:

• Type: most are [Kata] (special techniques). Some are [Attack] (attack bonuses).
• Energy: 2–5. For a 1-per-round limit, 2–3; for 1 per combat, 3–4; for 1 per session, 4–5.
• Check: attribute + skill + (an optional +1–3 bonus).
• Effect: define the effect in one sentence. Damage (Wounds) + status (status ailment) / environmental effect / ally effect.
• Limit: 1 per round (most common), 1 per combat, 1 per session. The usage-frequency limit of this masterwork technique.

The masterwork technique is the 5th slot, not the 6th. Attack A · Attack B · Defense · Licensed technique · masterwork technique = 5. Do not add slots.

The +3 cap: a masterwork technique's +attack bonus is generally within +3. It follows the limited-condition balance of ex2-00-05 §10.

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#§ Law — Data Template

The completed form of a masterwork that has passed through the 7 stages:

### [masterwork name] (kanji)

#### Scent — [compressed to one line]

[a 2–3 paragraph anecdote — era / swordsmith / owner / event]

#### Law — [base weapon] foundation + masterwork technique

**Base techniques**: same as [base weapon].

| Technique | Type | Energy | Check | Effect | Limit |
|------|------|------|------|------|------|
| **[masterwork] [technique name] ([kanji])** | [Kata/Attack] | [2–5] | [2d10+attribute+skill+bonus >= Defense] | [effect] | [round/combat/session N times] |

**Blessing [Aptitude]**: [blessing effect] (if any)

**Curse [Aptitude]**: [curse effect] (if any)

**Ownership condition**: [relationship type + concrete condition]

**Acquisition scenario**: [scenario category, links to this volume or another fc]

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#§ Law — Wrong Examples / Corrected Examples

#Wrong Example 1 — Adding Slots

Wrong: "This masterwork has two masterwork-technique slots — one for a strong strike and one for infiltration."

The masterwork slot is 1. To put two effects into one masterwork technique — combine them into one slot with a conditional effect.

Corrected: "[masterwork] X — effect A. When used in a stealth state, replaced by effect B."

#Wrong Example 2 — Imitating a Divine Treasure

Wrong: "This masterwork triggers the protection of deity X with a devotion technique."

A masterwork has no devotion slot. To elevate to a Divine Treasure is the domain of co-07-03.

Corrected: Convert the devotion effect into a weak blessing. "Blessing [Aptitude]: protection of deity X — (a small effect)."

#Wrong Example 3 — Energy / Wounds Confusion

Wrong: "Curse: 1 damage to action points each breath."

Energy is action points, Wounds is fatal-injury durability. Mixed expressions are forbidden.

Corrected: "Curse: each breath Energy -1" (loss of action points) or "Curse: at the end of each combat Wounds -1" (damage).

#Wrong Example 4 — Locking Out the PC

Wrong: "Ownership condition: only direct descendants of the Miyamoto house. If another carries it, the weapon has no effect."

Even if the Miyamoto house is fictional — a PC with no Miyamoto direct descendant within the campaign can never use this masterwork in a lifetime. A PC lockout.

Corrected: "Ownership condition: a direct descendant of the Miyamoto house or the house's recognition (acquirable via scenario)." Set a detour.

#Wrong Example 5 — Era Contradiction

Wrong: An uchigatana masterwork appears in a Heian-era scenario.

There is no uchigatana in the Heian. There is only the tachi.

Corrected: Convert to a tachi masterwork of the same effect. Or reclassify as a Spirit Realm Wandering Treasure.

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#§ Law — Masterwork vs Divine Treasure Determination

When making a new weapon, reconfirm at the end of the 7 stages whether it is a masterwork or a Divine Treasure.

Apply the §01-02 Masterwork and Divine Treasure Checklist.

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#§ Law — Introducing It as a Scenario Reward

1 new masterwork is one scenario's reward — or one scenario's motive. Recommended:

About 1–2 new masterworks within one campaign is appropriate. Too many, and a masterwork's weight grows light.

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#§ Law — 7-Stage Checklist

A final check after authoring a new masterwork:

• [ ] Is the era clear? (or is there a Spirit Realm Wandering Treasure tag?)
• [ ] Is the owner clear? In whose hand was it?
• [ ] Does the weapon category fit the era?
• [ ] Is the anecdote compressed to one line?
• [ ] Can the ownership condition be fulfilled by the PC via scenario?
• [ ] Is the curse / blessing not an automatic punishment? Is there a path to recover?
• [ ] Does the masterwork technique fit exactly within the 5th slot? Is it within the +3 cap?
• [ ] Is there no Energy / Wounds confusion?
• [ ] Have you reconfirmed the boundary between masterwork and Divine Treasure?
• [ ] Does its role not overlap with a body-listed masterwork?

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#Reference Links

• Weapon Catalog
• Masterwork Compendium
• Divine Treasures
• GM Tools Index
• The Relationship Between Weapon and Owner
• Curses, Blessings, Devotion
• Sample New Masterwork Weapons
• Swordsmith Additional Traits

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A new masterwork is not completed by data — it is completed when it gains a scene to appear in.