Mechanics Design

Mechanics Design — Systems & Interactions

Define, document, and validate the systems that make up how your game actually plays — from individual mechanics to emergent system interactions.

Inputs

• Game concept or GDD (use /game-concept or /game-design-document first)
• Core design pillars
• Target feel (fast/slow, simple/complex, deterministic/random)

Step 1: Mechanic Inventory

List every mechanic the game will have. Categorize by type:

Mechanic Definition Template

For each core mechanic, define:

## Mechanic: [Name]

**Input:** [What the player does — button, gesture, decision]
**Process:** [What the system calculates]
**Output:** [What changes in the game state]
**Feedback:** [What the player sees/hears/feels]
**Depth:** [How mastery changes the experience]

Example — Dodge Roll:
  Input: Press B + direction
  Process: i-frames(0.3s), velocity(8m/s, 0.4s), stamina(-15)
  Output: Player repositioned, temporarily invulnerable
  Feedback: Whoosh SFX, blur trail VFX, camera slight shake
  Depth: Frame-perfect dodge → counter window opens

Step 2: System Architecture

Map how systems connect:

┌─────────────┐     ┌──────────────┐     ┌─────────────┐
│   COMBAT    │────→│  HEALTH/DMG  │────→│   DEATH/    │
│   SYSTEM    │     │   SYSTEM     │     │   RESPAWN   │
└──────┬──────┘     └──────┬───────┘     └─────────────┘
       │                   │
       │            ┌──────┴───────┐
       │            │  EQUIPMENT   │
       │            │   SYSTEM     │
       │            └──────┬───────┘
       │                   │
┌──────┴──────┐     ┌──────┴───────┐
│  ABILITY    │────→│  RESOURCE    │
│  SYSTEM     │     │  SYSTEM      │
└─────────────┘     └──────────────┘

System Interaction Matrix

Step 3: Core Loop Engineering

Loop Layers

MICRO LOOP (seconds):
  See threat → Choose action → Execute → Read feedback → Adapt
  Frequency: Every 1-5 seconds
  Emotion: Tension, flow, reflex

MESO LOOP (minutes):
  Enter area → Explore/fight → Find resources → Upgrade → Move on
  Frequency: Every 5-15 minutes
  Emotion: Curiosity, accomplishment, decision-making

MACRO LOOP (session):
  Set goal → Attempt run/quest → Succeed or fail → Unlock progress → New goal
  Frequency: Every 30-90 minutes
  Emotion: Satisfaction, anticipation, mastery

META LOOP (long-term):
  Complete chapter → Unlock new region/mode → Master systems → Endgame
  Frequency: Over hours/days/weeks
  Emotion: Investment, identity, completionism

Feedback Loop Types

Step 4: Numeric Foundation

Core Formulas

Damage = (BaseDamage × WeaponMultiplier × SkillBonus) - (TargetArmor × ArmorEfficiency)

Time-to-Kill = TargetHP / (DPS - EffectiveArmor)

Resource Generation Rate:
  Early game: 10 units/min
  Mid game:   25 units/min (with upgrades)
  Late game:  60 units/min (with automation)

Difficulty Scaling:
  EnemyHP = BaseHP × (1 + (0.15 × ZoneLevel))
  EnemyDmg = BaseDmg × (1 + (0.10 × ZoneLevel))

Economy Sink/Source Balance

SOURCES (currency in)        SINKS (currency out)
─────────────────────        ────────────────────
Quest rewards: 40%           Equipment: 35%
Enemy drops: 30%             Consumables: 25%
Selling items: 20%           Upgrades: 20%
Exploration: 10%             Services/fast-travel: 15%
                             Cosmetics: 5%

Step 5: State Machines

Define key entity states:

PLAYER STATES:
  Idle ──[input]──→ Moving
  Moving ──[attack]──→ Attacking
  Attacking ──[hit]──→ Stagger (0.2s) ──→ Idle
  Any ──[damage while HP>0]──→ Hurt (0.5s) ──→ Previous
  Any ──[HP≤0]──→ Dead ──[respawn]──→ Idle

ENEMY AI STATES:
  Patrol ──[detect player]──→ Alert
  Alert ──[in range]──→ Engage
  Engage ──[HP < 30%]──→ Flee | Berserk
  Engage ──[player out of range]──→ Search (10s) ──→ Patrol

Step 6: Mechanic Validation Checklist

• Readable: Player can predict outcome before acting
• Responsive: Input-to-feedback under 100ms
• Meaningful: Every mechanic supports a design pillar
• Layered: Simple to learn, complex to master
• Interconnected: Mechanics combine for emergent play
• Bounded: Clear limits prevent exploits and confusion
• Tunable: Key values are exposed as data, not hardcoded
• Testable: Can be validated in isolation and in combination

Output

Save to artifacts/game-design/[project-name]-mechanics.md

Guidelines

• Mechanics are verbs — if you can't describe it as a player action, it's a system, not a mechanic
• Elegance over complexity — Chess has 6 piece types; Go has 1
• Design for the 80% case first, then handle edge cases
• Every number should be a variable in a config file, not a magic constant
• If two systems don't interact, question whether you need both
• Prototype the riskiest mechanic first — use /game-prototyping
• See /game-balancing for tuning numeric values after implementation