Mechanics Overview

Yomi no Sho is a complex game with many interlocking systems. This page is a high-level map of those systems and how they relate to each other, intended as a starting point for players who want to understand the game holistically. Each system has a dedicated page with full details; links are provided throughout.

The four systems

The game can be understood as four interlocking systems:

1. The combat system resolves individual fights. It is deterministic, tick-based, and governed by the damage formula described in Combat Basics.
2. The progression system advances Shades over time. It includes levelling, Ascension, and skill trees, and is the primary long-term goal of the game.
3. The economy system governs the flow of currencies and materials. It includes Munin, Binding Slips, Spirit Ember, Sanzu Coins, and the various zone-specific crafting materials.
4. The idle system generates resources passively. It is the game’s core loop and the reason Yomi no Sho is classified as an idle RPG rather than a traditional RPG.

Each system is described briefly below. The dedicated pages for each system are linked from the Mechanics sidebar group.

The combat system

Combat in Yomi no Sho is a deterministic, tick-based simulation. Each fight is divided into 0.5-second ticks, and within each tick, every combatant gains Action Points based on their Speed stat. When a combatant’s AP reaches 100, they take a turn. Actions resolve in a strict order: status effects tick, buffs and debuffs update, actions queue, actions resolve, deaths are checked, and end-of-tick effects fire.

The damage formula is multiplicative across several modifiers, which means small bonuses compound. A 10% damage buff, a 10% Defence break, and a 10% Crit Damage increase combine to produce a 33% damage increase, not a 30% increase. This is why debuff-focused supports like Yomotsu-Shikome are so powerful — their debuffs multiply with the rest of the party’s bonuses.

The affinity wheel governs elemental matchups. There are six affinities (Fire, Water, Wood, Metal, Earth, Void) arranged in a wheel, with strong matchups dealing +50% damage and weak matchups dealing −25% damage. The wheel matters most in tier-2 zones, where bosses have enough HP that affinity modifiers are the difference between a 30-second clear and a 5-minute grind.

For full details, see Combat Basics and Stats & Affinities.

The progression system

Shades progress through three primary axes: levels, Ascensions, and skill trees.

Levels are the most granular progression axis. Each level grants a small stat increase (roughly +2% to Attack and HP) and costs Munin. The cost curve is gentle until the soft cap at level 30, after which it becomes punishing. The intended path past a soft cap is an Ascension.

Ascensions are major progression milestones. Each Ascension resets the Shade’s level to 1, but permanently increases their base stats by 12% and expands their skill tree with a new tier. The Ascension ritual requires a Shade at the current soft cap, a set of zone-specific materials, and a Sanzu Coin. There are five Ascension tiers, with the level cap increasing from 30 to 60 to 90 to 120 to 150.

Skill trees are the third progression axis. Each Shade has a tier-0 skill tree available from level 1, and each Ascension unlocks a new tier. Skills are upgraded with Spirit Ember, the rarest of the three primary progression resources. Skill choices are not permanent — they can be reset for a small Munin cost — but the community has converged on optimal builds for each Shade, documented on their character pages.

For full details, see Progression & Ascension and Skill Trees.

The economy system

Yomi no Sho has five primary currencies and a long tail of zone-specific crafting materials. The primary currencies are:

• Munin — the universal progression currency. Used to level Shades, unlock skills, and ascend gear. Earned from every combat encounter and from the idle system.
• Binding Slips — the summoning currency. Each summon costs 10 Slips and yields a random Shade. Earned from one-time quest completions, zone drops, and the monthly login bonus.
• Spirit Ember — the skill upgrade currency. The rarest of the three primary resources. Earned from world boss fights and from the dismantling of unwanted gear.
• Sanzu Coins — the Ascension currency. Each Ascension requires one coin. There is no farmable source; coins are awarded only from one-time quest completions, world boss first-clears, and the monthly login bonus.
• Matsuri — the event currency. Earned during festivals and used to purchase festival-specific items. Does not persist between festivals.

The zone-specific crafting materials are too numerous to list here; each zone has 2–4 materials that drop only from encounters in that zone. The materials are used to craft gear and to perform Ascensions, and the drop rates are calibrated to gate progression at each tier.

For full details, see Crafting and the Items Index.

The idle system

The idle system is the game’s core loop. When the player is not actively playing, their Shades continue to fight in the zone they were last deployed to, accumulating Munin and items at a reduced rate. The idle accumulation is capped at 12 hours; excess is lost.

The idle rate is determined by the zone’s base yield, the party’s clear speed, and the Shade’s idle affinity stat (a hidden stat that varies by Shade). A party that can clear the zone’s encounters quickly will accumulate idle resources faster than a party that struggles, which creates an incentive to deploy your strongest party to the highest-yield zone you can clear reliably.

The idle system is also the source of the game’s “AFK boss” mechanic: certain world bosses can be challenged passively, with the player’s party fighting the boss automatically at regular intervals. The AFK boss is a significant source of high-tier materials and is the primary progression path for accounts that cannot actively play every day.

How the systems interact

The four systems are designed to interlock in a specific way:

• The combat system determines what zones the player can clear.
• The progression system advances the player’s Shades, allowing them to clear harder zones.
• The economy system gates the progression system, requiring the player to engage with the combat system to earn the resources needed for progression.
• The idle system allows the progression system to advance even when the player is not actively engaged with the combat system, which keeps the game accessible to players with limited playtime.

The interlock creates a tight loop: clear zones to earn resources, spend resources to progress Shades, progress Shades to clear harder zones. The loop is paced by the soft caps in the progression system and by the rare-currency gates in the economy system, which prevent the loop from being completed too quickly.

Where to go next

• Stats & Affinities — full details on the combat system’s underlying numbers.
• Skill Trees — full details on the progression system’s skill mechanics.
• Crafting — full details on the economy system’s crafting subsystem.
• Combat Basics — the player-facing guide to the combat system.
• Progression & Ascension — the player-facing guide to the progression system.