Game Godot Genre Simulation

Genre: Simulation / Tycoon

Optimization, systems mastery, and satisfying feedback loops define management games. This skill provides expert patterns, anti-patterns, and production-grade Godot implementations for simulation and tycoon genres (SimCity, RollerCoaster Tycoon, Factorio, Two Point Hospital).

When to Use

Use this skill when building management simulations, tycoon games, city builders, or resource optimization games in Godot 4.2+. Trigger keywords: tycoon, economy system, resource management, time scale, feedback loop, progression unlock, simulation tick, city builder, production chain, logistics grid.

Prerequisites

• Godot 4.2 or above (stable). Never use deprecated APIs from earlier versions.
• Windows host is primary (PowerShell). All path examples use Windows conventions (res://, ~).
• Familiarity with Godot Resource, RefCounted, Node, Signal, and @export systems.
• Scripts referenced below live in scripts/ relative to this skill folder.

Procedure

1. Load Expert Components

Before writing any simulation code, load the reference scripts from scripts/:

2. Design the Economy (Multi-Resource System)

The heart of any tycoon game is its economy. Key principle: multiple interconnected resources that force trade-offs.

class_name TycoonEconomy
extends Node

signal resource_changed(resource_type: String, amount: float)
signal went_bankrupt

var resources: Dictionary = {
    "money": 10000.0,
    "reputation": 50.0,
    "workers": 0,
    "materials": 100.0,
    "energy": 100.0
}

var resource_caps: Dictionary = {
    "reputation": 100.0,
    "workers": 50,
    "energy": 1000.0
}

func modify_resource(type: String, amount: float) -> bool:
    if amount < 0 and resources[type] + amount < 0:
        if type == "money":
            went_bankrupt.emit()
        return false

    resources[type] = clamp(
        resources[type] + amount,
        0,
        resource_caps.get(type, INF)
    )
    resource_changed.emit(type, resources[type])
    return true

Income/Expense Tracking — always provide detailed breakdowns so players can make optimization decisions:

class_name FinancialTracker
extends Node

var income_sources: Dictionary = {}
var expense_sources: Dictionary = {}

signal financial_update(profit: float, income: float, expenses: float)

func calculate_tick() -> float:
    var total_income := 0.0
    var total_expenses := 0.0

    for source in income_sources.values():
        total_income += source

    for source in expense_sources.values():
        total_expenses += source

    var profit := total_income - total_expenses
    financial_update.emit(profit, total_income, total_expenses)
    return profit

3. Implement the Time System

Simulation games need controllable time with variable speed:

class_name SimulationTime
extends Node

signal time_tick(delta_game_hours: float)
signal day_changed(day: int)
signal speed_changed(new_speed: int)

enum Speed { PAUSED, NORMAL, FAST, ULTRA }

@export var seconds_per_game_hour := 30.0

var current_speed := Speed.NORMAL
var speed_multipliers := {
    Speed.PAUSED: 0.0,
    Speed.NORMAL: 1.0,
    Speed.FAST: 3.0,
    Speed.ULTRA: 10.0
}

var current_hour := 8.0
var current_day := 1

func _process(delta: float) -> void:
    if current_speed == Speed.PAUSED:
        return

    var game_delta := (delta / seconds_per_game_hour) * speed_multipliers[current_speed]
    current_hour += game_delta

    if current_hour >= 24.0:
        current_hour -= 24.0
        current_day += 1
        day_changed.emit(current_day)

    time_tick.emit(game_delta)

func set_speed(speed: Speed) -> void:
    current_speed = speed
    speed_changed.emit(speed)

4. Manage Entities (Workers, NPCs, Facilities)

Workers/NPCs:

# workstation.gd
class_name Workstation extends Node

func work(amount: float) -> void:
    print("Work done: ", amount)

# worker.gd
class_name Worker
extends Node

enum State { IDLE, WORKING, RESTING, COMMUTING }

@export var wage_per_hour: float = 10.0
@export var skill_level: float = 1.0
@export var morale: float = 80.0

var current_state := State.IDLE
var assigned_workstation: Workstation

func update(game_hours: float) -> void:
    match current_state:
        State.WORKING:
            if assigned_workstation:
                var productivity := skill_level * (morale / 100.0)
                assigned_workstation.work(game_hours * productivity)
                morale -= game_hours * 0.5
        State.RESTING:
            morale = min(100.0, morale + game_hours * 2.0)

func calculate_hourly_cost() -> float:
    return wage_per_hour

Buildings/Facilities:

class_name Facility
extends Node3D

@export var build_cost: Dictionary
@export var operating_cost_per_hour: float = 5.0
@export var capacity: int = 5
@export var output_per_hour: Dictionary

var assigned_workers: Array[Worker] = []
var is_operational := true
var efficiency := 1.0

func calculate_output(game_hours: float) -> Dictionary:
    if not is_operational or assigned_workers.is_empty():
        return {}

    var worker_efficiency := 0.0
    for worker in assigned_workers:
        worker_efficiency += worker.skill_level * (worker.morale / 100.0)
    worker_efficiency /= capacity

    var result := {}
    for resource in output_per_hour:
        result[resource] = output_per_hour[resource] * game_hours * worker_efficiency * efficiency
    return result

5. Implement Customer/Demand System

class_name Customer extends RefCounted:
    var patience: float = 60.0
    var spending_budget: float = 50.0

class_name CustomerSimulation
extends Node

@export var base_customers_per_hour := 10.0
@export var demand_curve: Curve

var customer_queue: Array[Customer] = []

func generate_customers(game_hour: float, delta_hours: float) -> void:
    var demand_mult = 1.0
    if demand_curve:
        demand_mult = demand_curve.sample(game_hour / 24.0)

    var reputation_mult = 1.0
    var economy_node = get_node_or_null("/root/Economy")
    if economy_node and "resources" in economy_node:
        reputation_mult = economy_node.resources["reputation"] / 50.0

    var customers_to_spawn := base_customers_per_hour * delta_hours * demand_mult * reputation_mult

    for i in int(customers_to_spawn):
        spawn_customer()

func spawn_customer() -> void:
    var customer := Customer.new()
    customer.patience = randf_range(30.0, 120.0)
    customer.spending_budget = randf_range(10.0, 100.0)
    customer_queue.append(customer)

6. Add Feedback Systems

Visual Feedback (floating income/expense indicators):

class_name ResourceFlowVisualizer
extends Node

@export var coin_scene: PackedScene

func show_income(amount: float, from: Vector2, to: Vector2) -> void:
    if not coin_scene:
        return
    var coin = coin_scene.instantiate() as Control
    coin.position = from
    add_child(coin)

    var tween := create_tween()
    tween.tween_property(coin, "position", to, 0.5)
    tween.tween_callback(coin.queue_free)

    var label := Label.new()
    label.text = "+$" + str(int(amount))
    label.position = from
    add_child(label)

    var label_tween := create_tween()
    label_tween.tween_property(label, "position:y", label.position.y - 30, 0.5)
    label_tween.parallel().tween_property(label, "modulate:a", 0.0, 0.5)
    label_tween.tween_callback(label.queue_free)

Statistics Dashboard (rolling income/expense graph):

class_name StatsDashboard
extends Control

@export var graph_history_hours := 24
var income_history: Array[float] = []
var expense_history: Array[float] = []

func record_financial_tick(income: float, expenses: float) -> void:
    income_history.append(income)
    expense_history.append(expenses)

    while income_history.size() > graph_history_hours:
        income_history.pop_front()
        expense_history.pop_front()

    queue_redraw()

func _draw() -> void:
    draw_line_graph(income_history, Color.GREEN)
    draw_line_graph(expense_history, Color.RED)

func draw_line_graph(history: Array[float], color: Color) -> void:
    if history.size() < 2:
        return
    for i in range(history.size() - 1):
        var p1 = Vector2(i * 10.0, history[i])
        var p2 = Vector2((i + 1) * 10.0, history[i + 1])
        draw_line(p1, p2, color, 2.0)

7. Implement Progression & Unlocks

class_name UnlockSystem
extends Node

var unlocks: Dictionary = {
    "basic_facility": true,
    "advanced_facility": false,
    "marketing": false,
    "automation": false
}

var unlock_conditions: Dictionary = {
    "advanced_facility": {"money_earned": 50000},
    "marketing": {"reputation": 70},
    "automation": {"workers_hired": 20}
}

var progress: Dictionary = {
    "money_earned": 0.0,
    "workers_hired": 0
}

func check_unlocks() -> Array[String]:
    var newly_unlocked: Array[String] = []

    for unlock in unlock_conditions:
        if unlocks[unlock]:
            continue

        var conditions := unlock_conditions[unlock]
        var all_met := true

        for condition in conditions:
            if progress.get(condition, 0) < conditions[condition]:
                all_met = false
                break

        if all_met:
            unlocks[unlock] = true
            newly_unlocked.append(unlock)

    return newly_unlocked

8. Advanced Patterns

Dependency-Graph Pattern (Production Chains)

Represent complex production chains (e.g., Raw Materials → Intermediate → Finished Goods) using nested Resource structures. This allows deep, recursive data definitions fully editable in the Inspector.

# item_resource.gd
class_name ItemResource extends Resource:
    @export var item_name: String = ""
    @export var base_value: int = 0

# production_recipe.gd
class_name ProductionRecipe extends Resource

@export var required_inputs: Dictionary[ItemResource, int] = {}
@export var output_item: ItemResource
@export var output_yield: int = 1
@export var production_time: float = 5.0

func can_produce(available_inventory: Dictionary[ItemResource, int]) -> bool:
    for input_item in required_inputs:
        var required_amount: int = required_inputs[input_item]
        var available_amount: int = available_inventory.get(input_item, 0)
        if available_amount < required_amount:
            return false
    return true

AStarGrid2D for Logistics & NPC Jobs

AStarGrid2D is specialized for 2D grids, eliminating the need to manually connect points. Ideal for factory floors, warehouse logistics, and NPC pathfinding in management sims. See scripts/simulation_patterns.gd for the full implementation.

class_name LogisticsGrid extends Node

var _astar_grid: AStarGrid2D

func _ready() -> void:
    _astar_grid = AStarGrid2D.new()
    _astar_grid.region = Rect2i(0, 0, 100, 100)
    _astar_grid.cell_size = Vector2(32, 32)
    _astar_grid.diagonal_mode = AStarGrid2D.DIAGONAL_MODE_ONLY_IF_NO_OBSTACLES
    _astar_grid.update()

func place_obstacle(cell_coords: Vector2i) -> void:
    if _astar_grid.is_in_bounds(cell_coords.x, cell_coords.y):
        _astar_grid.set_point_solid(cell_coords, true)

func get_npc_path(start_cell: Vector2i, target_cell: Vector2i) -> Array[Vector2i]:
    return _astar_grid.get_id_path(start_cell, target_cell)

CSV-to-Resource Workflow (Rapid Balancing)

Automate conversion of spreadsheet data (CSV) into native .tres files. Designers can balance thousands of entities in Excel/Google Sheets and "bake" them into performant Godot resources.

@tool
class_name CSVResourceBaker extends EditorScript

func _run() -> void:
    var csv_path := "res://data/balancing_sheet.csv"
    var output_dir := "res://data/generated_items/"

    var file := FileAccess.open(csv_path, FileAccess.READ)
    if not file: return

    var rows := file.get_as_text().split("\n", false)
    for i in range(1, rows.size()):
        var columns := rows[i].split(",", false)
        if columns.size() < 2: continue

        var item_name: String = columns[0].strip_edges()
        var base_value: int = columns[1].to_int()

        var new_item := ItemResource.new()
        new_item.item_name = item_name
        new_item.base_value = base_value

        ResourceSaver.save(new_item, output_dir + item_name.to_lower() + ".tres")

9. Godot-Specific Tips

1. UI: Use Control nodes extensively, Tree for lists, GraphEdit for connections.
2. Performance: Process entities in batches, not every frame. Use a Tick Manager.
3. Save/Load: Convert all game state to Dictionary for JSON serialization. For large saves, use threaded serialization or optimized binary .res formats—never parse large JSON on the main thread.
4. Isometric view: Use Camera2D with orthographic projection.
5. Low-power mode: Enable OS.low_processor_usage_mode for stationary management screens to save CPU/battery.

Pitfalls

HARD RULES (Never Violate)

• NEVER use floating-point for primary currency; strictly use Integer Cents (or fixed-point math) to prevent accumulated precision errors in financial models.
• NEVER process 1000+ entities individually in _process(); strictly use a Tick Manager to batch updates or process entities in rotating pools.
• NEVER rely on linear cost scaling; strictly use Exponential Growth (Base * pow(1.15, Level)) to maintain challenge and strategic tension.
• NEVER hide critical metrics from the player; strictly provide Detailed Breakdowns (Income vs. Expense) so players can make optimization-based decisions.
• NEVER allow infinite resource stacking; strictly enforce Logistical Caps (warehouses/silos) to create meaningful space-management gameplay loops.
• NEVER let the early game become a "Waiting Simulator"; strictly Front-Load Decisions and quick early wins to build player momentum.
• NEVER modify a shared Resource directly; strictly use duplicate() to avoid unintentionally updating every building of that type.
• NEVER tie simulation logic to the visual framerate; strictly use _physics_process() or delta accumulators for deterministic simulation results.
• NEVER update UI labels every frame; strictly use Event-Driven Signals to refresh UI ONLY when the underlying data changes.
• NEVER run heavy economic loops synchronously; strictly use WorkerThreadPool to offload complex calculations and prevent UI stutters.
• NEVER store massive resource data as Nodes; strictly use RefCounted or Data Resources to avoid the memory/CPU overhead of the SceneTree.
• NEVER ignore OS.low_processor_usage_mode; strictly enable it for stationary management screens to save massive CPU/Battery life.
• NEVER manipulate the SceneTree from background threads; strictly use call_deferred() for thread-safe UI updates.
• NEVER parse large JSON save files on the main thread; strictly use Threaded Serialization or optimized binary .res formats.
• NEVER use standard equality (==) for float comparisons; strictly use is_equal_approx() to prevent floating-point jitter failures in logic gates.
• NEVER use deprecated APIs; strictly use the latest stable versions of Godot 4.2 and above.
• NEVER ignore security best practices; strictly use secure coding practices to prevent vulnerabilities such as buffer overflows, SQL injection, and XSS.
• NEVER hardcode sensitive information; strictly use environment variables or secure storage solutions for sensitive data.

Common Design Pitfalls

Verification

Run through this checklist to verify your implementation:

• Implement a basic economy with integer currency (no floating-point for primary currency).
• Create a time system with adjustable speed (PAUSED, NORMAL, FAST, ULTRA).
• Implement a worker and facility system with morale, skill, and efficiency.
• Verify that AStarGrid2D pathfinding works correctly for NPCs by placing obstacles and checking returned paths.
• Test the CSV-to-Resource workflow with a sample CSV file in res://data/.
• Ensure UI updates are event-driven (signals) and not tied to _process().
• Check for any floating-point errors in financial calculations—use integer cents or is_equal_approx().
• Run performance tests with a large number of simulated entities (1000+) to confirm tick batching works.
• Ensure all dependencies are up-to-date and compatible with Godot 4.2+.
• Verify that all security best practices are followed, including secure storage of user save files and validation of transaction records.
• Confirm OS.low_processor_usage_mode is enabled on stationary management screens.
• Verify call_deferred() is used for all SceneTree modifications from background threads.
• Confirm shared Resource instances are duplicate()d before modification.

Related Skills

• Master Skill: godot-master