#Hatashiai — The One-Ma Duel

Contents

Hatashiai — The One-Ma Duel cover

Scope declaration / opt-in. This issue does not replace the canon combat. It is a co-99-01 Variant that, for a single 1:1 duel scene only, swaps zone combat out for a distance-based mini-engine. Energy, the single breath, the round, Defense, Wounds, tags, and stance all stay exactly as in canon; only position (zone) is changed into the ma (aiming distance) between the two combatants.
This issue is the duel engine for fc03 Chronicle of Japanese Sword Masters. fc03 stands 12 sword masters up as weekly-grade sheets and asks "if you fought him, how would you win" — this issue actually rolls out that one bout.

#Brief — What This Issue Is

In a pitched battle where many tangle together, zones are everything. Who takes the Front Zone, who drives into the Core Zone. But the moment two combatants stand facing each other with one sword apiece, all of that vanishes. What remains is just one thing — does the blade reach, or not. The difference of a half-step (半步).

So a duel has no Core Zone and no Rear Zone. Instead there is the distance, one ma at a time. Too far and the blade swings through empty air; step in once and it reaches; press in too close and a long sword becomes useless instead, and guards lock together. This minute dance of distance is the whole of a duel.

This issue handles that one bout.

What a duel is — why you draw a blade, the rite and the witnessing, and the aftermath once the blade has stopped. The split between sparring and shinken shobu. (01)
Ma and the blade — the distance ladder, the half-step, each weapon's ideal range, guard-to-guard, close fighting, and guard and hit location and wounds. (02)
Sparring and shinken shobu — the rules of the match and the rules of death, the regard of the formal onlookers (how to lose even when you win), fc03 sword-master conversion + Ganryujima sample. (03)

#Commentary — Zooming In on One Ma: From Pitched Battle to Ikkiuchi

This engine's distance ladder is not outside the canon zones but inside them. The single "range: adjacent" rung where two Front Zones lock together in canon — this issue's ma is that one rung zoomed in to five steps.

So when two warriors break off into an ikkiuchi in the middle of a pitched battle, the GM can just pull the pair out of that adjacent rung and move them into this engine. When the duel ends, they return to zone combat again. A duel within the pitched battle, a pitched battle within the duel — the two are connected by one ma.

Thesis. If zone combat is "where do you stand," a duel is "do you take that half-step in." Even with the same sword, that half-step divides life and death.

#Meta Card

Item	Value
Series	`zn` (one-shot series) issue 10
Title	Hatashiai — The One-Ma Duel
Nature	1:1 duel-focused distance-based mini-engine + rite/onlooker rules (swordplay/sword-master gadget)
Volume	4 documents (front + rite/reason + ma and the blade + sparring/shinken shobu) · reading time about 18 minutes
Blocks (whole issue)	Brief · Commentary · Scent · Rule · Table · Example · Note (this front document itself is Brief · Commentary · Scent)
Authority	opt-in (Variant) — limited to 1:1 scenes. Does not replace canon combat
Dependencies	`co-03` combat (round/wounds/zones) · `fc03` Chronicle of Japanese Sword Masters (sword-master weekly-grade)
Core version required	`co >= 1.2`
Current version	v1.3.1 (`zn10-VERSION`)

#Block Manifest

Below are the blocks of each sub-document (this front document itself is Brief · Commentary · Scent).

Document	Blocks	Contents
`01 Rite and Reason`	Note · Scent	Reasons for the duel, hatashijo, second, aftermath, the sparring/shinken shobu distinction
`02 Ma and the Blade`	Rule · Table · Scent	Ma distance ladder · half-step · weapon ideal range · guard-to-guard/close fighting · guard · hit location/wounds · terrain import
`03 Sparring and Shinken Shobu`	Rule · Commentary · Note · Example · Scent	Sparring rules · shinken shobu rules · formal regard (shigurui style) · fc03 sword-master conversion + Ganryujima sample
`99 Closing Fiction`	Scent	"Half-Step" — a swordsman standing in a match before the lord, the one cut that turns to ash even in victory

Reading order: front → 01 → 02 → 03. To roll out a bout right now, open the distance ladder in 02 first.

Closing fiction. At the end of this issue is "Half-Step" (pure Scent fiction) — 99.

#Production Notice

This issue is the 10th of the Konsei Reiyotan zn (one-shot) series. The rite, reason, and aftermath of the duel are based on real Japanese swordsmanship culture (hatashiai, katakiuchi, the dojo, matches before the lord), and the distance engine, guard, and hit-location rules are an opt-in Variant designed on top of canon co-03's Energy, tag, and wound system. No new attributes and no new skills were created. It links actively with fc03 Chronicle of Japanese Sword Masters, reproducing real cases such as the Ganryujima duel as engine demonstrations.

#AI Use Notice

A substantial part of this material was produced with the help of generative AI (LLM) in planning, drafting, prose tidying, and proofreading. The GPT Image 2 model was used in the image generation process. Claude Code and Codex were used for the Japanese and English translations. Final editing and the responsibility for publication rest with the creator.

Should there be changes to domestic or foreign law regarding AI-assisted works, those laws will be followed.

#Scent — One Sentence

"On the battlefield of a thousand, position kills a person; in the duel of two, the half-step kills a person."