#Dice System (骰子體系)

Contents

Two 10-sided dice resolve every check in this game. The bell curve of 2d10, the dramatic effect of doubles, and the tactical depth of Fate Intervention.

Related Entries: Basic Axioms §1,2 · Attributes · Checks and Saves · Glossary

Supporting Axioms: Axiom 1 (10-sided world), Axiom 2 (doubles and fate)

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#Basic 2d10 Check

#Scent — Ten Roads of Possibility

Two 10-sided dice roll across the table. One is the fate of the left hand; the other, the will of the right. When their numbers join, the result reflects the warrior's skill directly: not flat luck, but a bell curve where honed ability decides the outcome.

#Law — Rule

Roll two 10-sided dice at the same time and add them.

• Range: 2 ~ 20
• Average: 11
• Distribution: bell curve (results near 11 are most frequent; extremes are rare)
• Formula: 2d10 + modifier >= Target Number

#Probability Table

Impact of Modifiers: On a bell curve, a +1 modifier has more impact than +1 on a single flat die. In the middle band, where success and failure meet, +1 creates about an 8~10% difference in success rate. Attribute investment matters more than it would in a flat-die system.

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#Doubles (雙目)

#Scent — The Crossing of Fate

Both dice show the same number: 3 and 3, 7 and 7, 10 and 10. It is like the moment when two strands of fate meet at one point. Whether that becomes blessing or curse depends on whether the blade points at the enemy or cuts empty air.

#Law — Rule

On a 2d10 roll, a double triggers when both dice show the same face.

• Chance: 10% (1-1, 2-2, ... 10-10 = 10 outcomes/100 combinations)
• Combined with check success/failure, it creates 4 results:

Sense of Frequency: On average, 1 double appears every 10 rolls. Several doubles can explode in a single combat, adding tension to the rhythm of the fight. Heavenly Mandate (1%) and Karmic Retribution (1%) are rare enough to appear only once or twice across a whole session, so they carry strong narrative weight when they happen.

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#Critical Expansion (会心擴張)

Some techniques, divine items, and expansion rules explicitly state Critical Expansion. When this effect is present, a successful check is also treated as a Critical Hit if the difference between the two dice is exactly 1. For example, [8,7] and [4,5] become Critical Hits if the check succeeds.

Critical Expansion is not part of the basic check rules; it is a separate effect. A basic ambush only grants +2 to the first attack check. The Critical rule changes only when text explicitly states automatic Critical Hits, such as the shinobi 3rd-dan technique [Ambush].

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#Fate Intervention (運命介入)

#Scent — One Who Twists Heavenly Luck

For ordinary people, the dice result is fate. But those blessed by heavenly luck, or those who know how to squeeze it dry, can twist that fate with their fingertips, as if nudging a die face from 4 up to 5 just after the dice stop on the table. Heavenly luck is not infinite. Each use leaves a debt to the world.

#Law — Rule

Immediately after rolling 2d10, a character with the Fate (運) attribute may adjust the value of one d10 by ±1.

Use Conditions:

• Uses per battle: equal to the Fate modifier, but even if the Fate modifier is less than 1, at least 1 use
• Fate +3 → 3 uses, Fate +1 → 1 use, Fate +0 → 1 use, Fate -1 → 1 use (minimum guarantee)
• The d10 value must remain in the range 1~10 (cannot lower 1 to 0 or raise 10 to 11)
• Can be used only on your own roll (not on someone else's roll)

Even with low Fate, the last 1 intervention is guaranteed. In exchange, Fate is still used for luck checks, chance discoveries, danger intuition, and post-battle survival checks, so low Fate exacts its price outside combat and after falling.

Tactical Uses:

Design Intent: Fate Intervention is not "luck" but "decision." The choice to spend or save Fate exists at every moment. A Fate +3 character can make three decisive interventions during combat, and that alone can change the course of battle.

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#d100 Percentage Check

#Scent — Hundred Roads of Fate

Sometimes ten roads are not enough. What the wind brings onto the battlefield, what spell is written in a fallen secret manual, which part of the armor is struck by an oni's kanabo: such things are decided by a hundred roads of possibility.

#Law — Rule

Use 2d10, but read one die as the tens digit and one as the ones digit.

• Declare the reading order before rolling (by color, or first roll/later roll)
• Range: 01 ~ 00 (=100)
• Distribution: flat (all values 1%)

Main Uses:

• Decisive moment table (when Heavenly Mandate triggers)
• Critical mistake table (when Karmic Retribution triggers)
• Yoma encounter table (lull phase)
• Loot table (after battle)
• Spell runaway table (on spell failure)

Use Frequency: d100 is not an everyday check. It is used only in special situations: when a double erupts, when the GM rolls an environmental event, or when post-battle rewards are decided. Because it is not frequent, each roll feels like a special moment.

#Summary: Every Roll in This Game

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Every check is completed with two 10-sided dice.