Unit Statistics & Traits
Relevant source files
The following files were used as context for generating this wiki page:
Unit Statistics and Traits form the foundational data layer for combat, progression, and character differentiation within the Chapter Master project. This system defines the base capabilities of various unit types—ranging from Adeptus Astartes to Xenos threats—and modifies those capabilities through a complex hierarchy of permanent traits, psychic buffs, and chapter-wide advantages or disadvantages.
The architecture relies on JSON-based data structures to define base attributes (such as Ballistic Skill, Weapon Skill, and Constitution) and specific trait objects that apply mathematical modifiers (additions, subtractions, or multipliers) to these base values.
Base Unit Statistics
Every unit in the game is defined by a set of core attributes. In the primary data structure, most statistics are represented as an array containing a base value and a potential variance or secondary modifier.
Core Attributes
The system tracks several key performance indicators for each unit:
| Attribute | Description | Typical Range (Astartes) |
|---|---|---|
| ballistic_skill | Accuracy with ranged weaponry. | 30 - 55 |
| weapon_skill | Proficiency in melee combat. | 30 - 55 |
| strength | Physical power affecting melee damage. | 36 - 70 |
| constitution | Physical resilience and health pool. | 36 - 75 |
| dexterity | Agility and reaction speed. | 30 - 44 |
| intelligence | Tactical and technical aptitude. | 38 - 45 |
| piety | Spiritual resolve and resistance to corruption. | 28 - 32 |
| luck | Modifier for random favorable outcomes. | 10 (Base) |
Sources: datafiles/data/unit_stats.json:2-10, datafiles/data/unit_stats.json:157-170
Unit Data Structure Representation
Units are categorized by a base_group (e.g., astartes, human, ork, skitarii) and linked to a specific religion. Some units also define start_gear, including armor and weapons.
"marine": {
"ballistic_skill": [40, 5],
"base_group": "astartes",
"constitution": [40, 3],
"religion": "imperial_cult",
"strength": [40, 4],
"weapon_skill": [40, 5]
}
Sources: datafiles/data/unit_stats.json:155-185
Traits and Modifiers
Traits are specific characteristics that provide bonuses or penalties to a unit's base statistics. These can be innate (based on origin) or earned through experience.
Trait Architecture
The trait system uses a flexible mapping where each trait key contains the statistics it modifies. Modifiers can be simple integers or complex arrays defining minimum/maximum caps.
The diagram shows how individual traits are aggregated and applied to base unit stats to determine final combat effectiveness.
Sources: datafiles/data/traits.json:2-15, datafiles/data/traits.json:115-130, datafiles/data/traits.json:340-365
Significant Traits Table
| Trait ID | Display Name | Major Effects |
|---|---|---|
ancient | Ancient | +4 Ballistic Skill, +5 Wisdom, -1 Strength. |
champion | Champion | +10 Weapon Skill, +10 Ballistic Skill. |
lone_survivor | Lone Survivor | +8 WS/BS, +8 Constitution, +5 Luck. |
paragon | Paragon | +10 WS/BS/STR/DEX, +12 Constitution. |
tech_heretic | Tech Heretic | +1 Intelligence, +3 Technology. |
Sources: datafiles/data/traits.json
Chapter Advantages and Disadvantages
Beyond individual unit traits, the Chapter as a whole possesses "Advantages" and "Disadvantages" that act as global modifiers. These can affect unit spawning rates, specific equipment lethality, or starting specialist counts.
Global Modifier Types
- Weapon Specialties: Advantages like
Bolter Drillingprovide a 1.15x multiplier to the attack of "bolt" tagged weapons. - Doctrine Modifiers:
Assault Doctrineincreases melee skills, whileDevastator Doctrineincreases defense and heavy weapon attack. - Gene-seed Mutations: Disadvantages like
Black Ragegive units a chance to transform into "Death Company" units, which are locked to Assault roles.
This graph illustrates how chapter-level settings override or transform base unit definitions.
Sources: datafiles/main/chapter_advantages.json:17-29, datafiles/main/chapter_disadvantages.json:2-7, datafiles/main/chapter_advantages.json:235-241
Dynamic Buffs: Psychic Powers
Psychic powers provide temporary or situational modifications to unit statistics during combat. These are categorized into attack, buff, and debuff types.
Psychic Stat Modification
Some powers directly alter the internal state of a unit's attributes:
- Iron Arm: Transmutes flesh to living metal (Effectively a defensive buff).
- Might of the Ancients: Increases physical power to "unimaginable levels."
- Quickening: Grants precognitive powers to avoid enemy blows (DEX/WS related).
Sources: datafiles/data/psychic_powers.json:347-355, datafiles/data/psychic_powers.json:434-442, datafiles/data/psychic_powers.json:521-529
Specialist Units and Custom Roles
Chapters can define custom_roles which override default unit statistics and naming conventions. For instance, the Deathwatch replaces standard Captains with "Watch Captains" and assigns specific loadouts like the "Xenophase Blade".
Role Specialization Flow
- Base Template: Load
marinestats. - Chapter Override: Apply
custom_roles(e.g., "Grand Master" for Consecrators). - Squad Formation: Units are placed in
custom_squads(e.g., "Kill Team") which may enforce specific weapon requirements or attribute caps.
Sources: datafiles/main/chapters/33.json:330-345, datafiles/main/chapters/33.json:380-410
The integration of unit-level statistics with trait-based modifiers and chapter-level doctrines creates a highly granular system where two units of the same type can have significantly different performance profiles based on their history and chapter affiliation.