one dataset · paper, tables, graph, wiki
simgrammar the grammar of simulation

parts

21 mechanics, as Crusader Kings III does them

core · 4

population & lineage

Dynasty succession

On death, play passes to the player heir and titles pass under the realm's succession law, so partition can split a realm among children; the game ends if no viable heir remains, and dynasty heads spend Renown on bonuses for every dynasty member.

social relations

Opinion modifiers

Each character's opinion of another is an itemized list of modifiers from traits, relations, actions, and events, many expiring over time; discontented vassals join factions pressing for independence, a rival claimant, or less crown authority.

agents & behavior

Personality traits

Personality, education, and genetic traits modify the six skills (Diplomacy, Martial, Stewardship, Intrigue, Learning, Prowess), opinions, and which event options a character can take.

agents & behavior

Stress accumulation

Acting against personality traits and suffering events add stress; crossing stress levels fires mental-break events whose coping options can add traits (from level 2 up), and extreme stress can kill the character.

supporting · 17

agents & behavior

Agent skills

Skills grow from education and from perks in six lifestyles, each with three skill trees.

information & legibility

Causal breakdown tooltips

Nested tooltips let players open explanations of terms inside other tooltips.

population & lineage

Culture and religion conversion

Counties carry a faith and a culture; the court chaplain can convert a county's faith and the steward can promote the ruler's culture, while faith hostility sets opinion penalties from 0 to -30.

social relations

Faction diplomacy

Wars are fought over claims, and marriages and alliances link realms.

population & lineage

Lifecycle and aging

multiplayer & persistence

Modding API

Event, trigger, and effect scripts and game data files are moddable; total conversions replace the setting.

governance & policy

Political capital

Prestige and piety accrue from rank, traits, and deeds and are spent on actions such as creating titles (prestige) and faith decisions (piety).

social relations

Relationship values

Friends, rivals, and lovers form between characters and shift opinions and event outcomes.

social relations

Romance and family

Marriages create alliances and heirs, making match choice a political decision.

governance & policy

Stability and unrest

Vassal factions accumulate strength and can revolt when their demands are refused.

conflict & defense

Statistical combat resolution

Battles resolve from army size, men-at-arms, knights, commander skill, and terrain, in phases that run until one side is routed.

progression & goals

Tech tree

Lifestyle perk trees and cultural innovations unlock abilities and buildings.

conflict & defense

Territorial control

Counties belong to titles with de jure hierarchies, and wars are fought to press claims on them; conquered counties start with low county control.

population & lineage

Trait inheritance

Genetic traits such as strong or poor health pass to children.

narrative & generation

Triggered event chains

Events are called from on_actions, decisions, and interactions, with weighted options and scheduled follow-ups.

conflict & defense

War score and peace terms

War score from battles and occupation lets the attacker enforce the war goal at full score, while either side can offer white peace.

core loop

play the current ruler -> manage vassal opinion, council, and stress -> arrange marriages, schemes, and wars over claims -> ruler dies -> heir inherits titles under succession law -> realm fragments or consolidates

design notes

CK3 makes the player a character rather than a state: realm strength depends on vassals whose itemized opinions, traits, and family ties decide whether they serve or rebel. Succession laws make death the main source of disruption, and stress penalizes playing a character against type, which pushes players to roleplay their traits. Event content is authored but fired from on_actions and character state, so the same templates produce different stories in different courts; culture and religion conversion is not yet a mechanic in the taxonomy (proposal culture-religion-conversion).

appears in

the paper, 3 sections · 5 chapters · 3 episodes
paper

3. The catalog

linked in this section of the paper

paper
paper

5. The structure of the design space

linked in this section of the paper

paper
paper

Appendix A. Game catalog

linked in this section of the paper

paper
catalog

The catalog

listed with its year, developer, subgenre, and number of mechanics

book
ch 5
book
ch 6

Chapter 6. Five ceilings

linked from the text

book
ch 8

Chapter 8. Where AI lands

named in the text

book
ch 9

Chapter 9. Vacant lots

linked from the text

book
ch 10

Chapter 10. Bets

linked from the text

book
ep 5

The five ceilings

on screen at 1:29 content made by hand

episode
ep 7

Where AI lands

on screen at 2:33 explanation by hand, 4:15 what they'd change

episode
ep 8

Vacant lots

on screen at 0:26 the missing story, 4:44 research by people

episode

sources

3
Wikipedia contributors (2026). Crusader Kings III. Wikipedia
CK3 Wiki contributors (2026). Event modding (Crusader Kings III). Crusader Kings III Wiki (paradoxwikis.com)

provenance

runs in log/runs
2026-10-24
created2026-10-24-catalog-gicatalog
2026-10-24
reviewed2026-10-24-review-fixesmaintenance
2026-10-25
reviewed2026-10-25-contributor-readinessmaintenance