Chapter 57 — Composition Guide

Chapter 57 — Composition Guide

AI RPG Engine ships 10 starter worlds. They are examples, not templates. Each one demonstrates how to combine engine modules into a game with its own combat identity, resource economy, and narrative pressure.

This chapter shows you how to build your own game by composing the same pieces the starters use.

---

The Shape of a Game

Every game built on the engine has the same structure:

stat mapping → combat stack → modules → content → Engine constructor

You define stats, configure combat, pick the modules you need, create your content (entities, zones, dialogue), and wire it all into new Engine(). That’s the whole pattern.

The starters add demo glue on top — scripted event listeners for item gifts, audio cues, and fallout hooks. Those are polish, not architecture.

---

Step 1: Name Your Stats

Every game needs a stat mapping — three stat roles that drive every combat formula:

Role	What It Drives	Example Names
Attack	Damage, guard breakthrough	vigor, might, brawn, chrome, grit, fitness
Precision	Hit chance, disengage, guard counter	instinct, agility, cunning, reflex, perception, wits
Resolve	Guard absorption, brace resistance, morale	will, composure, sea-legs, command, presence, nerve

The golden rule: three distinct stats, never collapse attack = resolve. If your attack and resolve map to the same stat, guard breakthrough becomes trivial and combat loses its tension.

const statMapping = { attack: 'might', precision: 'agility', resolve: 'will' };

You can define stats beyond these three — exploration stats, social stats, crafting stats. The mapping only governs combat formulas.

---

Step 2: Choose Your Combat Stack

buildCombatStack is the recommended entry point. It generates formulas, wraps them with engagement and resource modifiers, sets up review tracing, and returns a module array.

Minimal combat (no resources, no engagement roles)

import { buildCombatStack } from '@ai-rpg-engine/modules';

const combat = buildCombatStack({
  statMapping: { attack: 'might', precision: 'agility', resolve: 'will' },
  playerId: 'hero',
});

Combat with a resource profile

const combat = buildCombatStack({
  statMapping: { attack: 'might', precision: 'agility', resolve: 'will' },
  playerId: 'hero',
  resourceProfile: {
    packId: 'my-game',
    gains: [
      { trigger: 'attack-hit', resourceId: 'momentum', amount: 2 },
    ],
    spends: [
      { action: 'attack', resourceId: 'momentum', amount: 5, effects: { damageBonus: 2 } },
    ],
    drains: [],
    aiModifiers: [],
  },
});

Combat with engagement roles

const combat = buildCombatStack({
  statMapping: { attack: 'might', precision: 'agility', resolve: 'will' },
  playerId: 'hero',
  engagement: {
    backlineTags: ['ranged', 'caster'],
    protectorTags: ['bodyguard'],
  },
  biasTags: ['undead', 'beast'],
});

See Build a Combat Pack for deep combat authoring.

---

Step 3: Wire Your Modules

Pick the modules your game needs:

import { Engine } from '@ai-rpg-engine/core';
import { traversalCore, statusCore, buildCombatStack, createDialogueCore, createCognitionCore, /* ... */ } from '@ai-rpg-engine/modules';

const combat = buildCombatStack({ /* ... */ });

const engine = new Engine({
  manifest: { id: 'my-game', title: 'My Game', version: '1.0.0' },
  seed: 42,
  modules: [
    traversalCore,
    statusCore,
    ...combat.modules,
    createDialogueCore(myDialogues),
    createCognitionCore({ decay: { baseRate: 0.02 } }),
    // ... add what you need
  ],
});

If your game has…	You need
Rooms to move between	traversalCore
Combat	buildCombatStack
NPC dialogue	createDialogueCore
NPC beliefs and memory	createCognitionCore
Items and equipment	createInventoryCore
Factions	createFactionCognition
Character abilities	createAbilityCore + createAbilityEffects
Boss encounters	createBossPhaseListener

---

Step 4: Create Your Content

engine.store.addZone({ id: 'cave', name: 'Goblin Cave', tags: ['dark'], exits: [{ to: 'clearing' }] });
engine.store.addEntity({ id: 'hero', type: 'player', name: 'Fighter', tags: ['human'], stats: { might: 6, agility: 5, will: 4 }, resources: { hp: 25, maxHp: 25 }, inventory: [], equipment: {}, statuses: [] });
engine.store.state.playerId = 'hero';
engine.store.state.locationId = 'cave';

---

Remixing Starters

Starter	Best Pattern to Borrow
Fantasy	Simplest combat wiring — no resources, no engagement roles
Weird West	buildCombatStack usage, dual resource profile
Cyberpunk	Squad engagement with backline/protector tags
Detective	Defensive resource spending
Pirate	Crew morale as shared group resource
Zombie	Consequence-only resource (infection)
Vampire	Opposing dual resources (bloodlust vs humanity)
Gladiator	Performance economy, 3-phase boss
Ronin	Multiple protector roles, dual-layer resources

---

See Also

• Build a Combat Pack — deep combat authoring
• Combat Overview — the six pillars
• Tuning Philosophy — what to tune vs leave alone
• Modules — module system architecture