Dark urban city skyline at night, neon lights reflecting on wet streets, deep shadows, atmospheric low-key lighting

GrandTheftAuto Style.

A complete blueprint for building an open world crime sandbox. Car chases, police AI, gang missions, weapons, and a living city — all starting from zero.

6+Game Systems
4Map Zones
3Game Engines
100+Starter Assets
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Core
Mechanics.

Every system you need to build a believable open world crime sandbox.

City skyline at night, dark urban environment, neon reflections on wet pavement, deep shadows between tall buildings

Living City Grid

A fully navigable urban environment with 4 distinct zones — downtown skyscrapers, desert highways, rural villages, and a restricted military area.

Sports car speeding through dark tunnel, motion blur, dramatic low-key lighting, black environment

Arcade Car Physics

Drift, brake, and boost through traffic. Rigidbody-based vehicle controller with realistic wheel friction and crash deformation.

Police Pursuit AI

Wanted level system (1–5 stars). Police units spawn, radio for backup, and use roadblocks. Escape by losing line-of-sight.

3-star wanted

Objective System

Quest markers, NPC dialogue triggers, timed objectives, and fail states. Supports car chases, bank heists, and gang territory battles.

Car ChaseHeistGang WarDelivery

Day/Night System

Real-time directional lighting that rotates over 24 in-game minutes. NPCs change behavior, police visibility drops at night.

14:24

Pick Your
Stack.

PlayerMovement.cs — Unity C# Starter
1// GTAPrototype — Unity C# PlayerMovement.cs2// Attach to Player GameObject with Rigidbody component34using UnityEngine;56[RequireComponent(typeof(Rigidbody))]7public class PlayerMovement : MonoBehaviour8{9    [Header("Movement Settings")]10    public float walkSpeed = 5f;11    public float runSpeed = 10f;12    public float jumpForce = 6f;13    public float gravity = -20f;1415    [Header("Ground Check")]16    public Transform groundCheck;17    public float groundDistance = 0.4f;18    public LayerMask groundMask;1920    private Rigidbody rb;21    private bool isGrounded;22    private bool isRunning;2324    void Start()25    {26        rb = GetComponent<Rigidbody>();27        rb.freezeRotation = true;28        Cursor.lockState = CursorLockMode.Locked;29    }3031    void Update()32    {33        // Ground detection34        isGrounded = Physics.CheckSphere(35            groundCheck.position,36            groundDistance,37            groundMask38        );3940        isRunning = Input.GetKey(KeyCode.LeftShift);4142        // Jump43        if (Input.GetButtonDown("Jump") && isGrounded)44        {45            rb.AddForce(Vector3.up * jumpForce, ForceMode.Impulse);46        }47    }4849    void FixedUpdate()50    {51        float h = Input.GetAxis("Horizontal");52        float v = Input.GetAxis("Vertical");5354        float speed = isRunning ? runSpeed : walkSpeed;55        Vector3 move = transform.right * h + transform.forward * v;5657        rb.MovePosition(rb.position + move * speed * Time.fixedDeltaTime);5859        // Apply custom gravity60        if (!isGrounded)61            rb.AddForce(Vector3.up * gravity, ForceMode.Acceleration);62    }63}

Ride Everything.

4 vehicle classes with distinct physics profiles and spawn locations.

Red sports car at night, dark background, dramatic low-key studio lighting, deep shadows

180 mph

Sports Cars

High-speed pursuit vehicles. Fastest acceleration in the game.

Motorcycle on dark road at night, motion blur, atmospheric moody lighting, black environment

160 mph

Motorcycles

Weave through traffic. Narrow profile for alley escapes.

Heavy truck on dark highway at night, dim atmospheric lighting, deep shadows, industrial environment

80 mph

Heavy Trucks

Demolish roadblocks. Ram police cruisers. Slow but unstoppable.

Police car at night with blue and red lights, dark urban environment, dramatic low-key lighting, deep shadows

140 mph

Police Cruisers

AI-controlled pursuit vehicles. Spawn at 2+ wanted stars.

4 Zones.

Each zone has distinct aesthetics, NPC density, and threat level.

Dense city downtown at night, neon lights, skyscrapers, wet streets reflecting city glow, deep shadows between buildings

Downtown Core

Skyscrapers, traffic gridlock, gang territories, and the city bank. Highest wanted level activity.

Empty desert highway at night, dark sky, minimal lighting, vast dark landscape, atmospheric dim environment

Desert Highway

Open road, sparse police presence. Ideal for high-speed chases and illegal drag races.

Rural countryside at night, dark fields, dim village lights in distance, atmospheric moody environment, deep shadows

Rural Villages

Low-traffic zone. Hidden safehouses, weapons caches, and off-road terrain.

Military base at night, dark industrial environment, dim floodlights, deep shadows, restricted area atmosphere
5★ Instant

Military Restricted Area

Instant 5-star wanted level on entry. Military vehicles, helicopter pursuit, and tank spawns. End-game challenge zone.

Story
Missions.

4 mission templates ready to implement with objectives, steps, and reward structures.

01
Car Chase// MEDIUM

Highway Pursuit

$4,200

Objective

Intercept and destroy the armored van before it reaches the airport. 3-minute timer. Police spawn at 90 seconds.

Mission Steps

  1. 1.Steal a fast vehicle from the impound lot
  2. 2.Tail the van through downtown traffic
  3. 3.Force the van off the highway bridge
  4. 4.Escape with 3-star wanted level
02
Bank Robbery// HARD

First National Heist

$18,500

Objective

Breach the vault, neutralize security, and escape via the underground tunnel before SWAT arrives in 6 minutes.

Mission Steps

  1. 1.Acquire disguises from the dry cleaner
  2. 2.Disable the alarm system remotely
  3. 3.Blow the vault door with C4
  4. 4.Drive the cash to the safehouse
03
Combat Mission// HARD

Gang Territory War

$8,000

Objective

Capture 3 territory control points in the Southside district. Hold each for 60 seconds against rival gang reinforcements.

Mission Steps

  1. 1.Eliminate the gang lookouts on the rooftop
  2. 2.Move to capture Point Alpha
  3. 3.Defend against 2 waves of reinforcements
  4. 4.Hold all 3 points simultaneously
04
Delivery Run// EASY

Midnight Delivery

$1,800

Objective

Deliver the unmarked package from the docks to the warehouse in the industrial zone. No weapons — stay off police radar.

Mission Steps

  1. 1.Pick up the package at Pier 7
  2. 2.Avoid police checkpoints on Route 9
  3. 3.Deliver to the warehouse before dawn
  4. 4.Collect payment from the contact

Next
Steps.

8 systems to build after the core prototype is running. Prioritized by gameplay impact.

Get Starter Code
01

3D Characters

Rigged humanoid models with blend shape facial animations. Import Mixamo characters directly into Unity or Unreal.

High Priority
02

Weapons System

Pistols, rifles, shotguns, and melee. Ammo management, reload animations, and bullet physics with Raycast hit detection.

High Priority
03

Multiplayer Mode

Photon or Mirror networking for 2–8 players. Sync player positions, vehicle states, and mission objectives in real-time.

Medium Priority
04

Story Mode

Branching narrative with 3 acts. Dialogue trees using Yarn Spinner. Player choices affect gang relationships and city state.

Medium Priority
05

Traffic AI

NavMesh-based civilian vehicles that obey traffic lights, react to player chaos, and scatter during police chases.

Medium Priority
06

Character Animation

Animator Controller with locomotion blend tree. Smooth transitions between walk, run, crouch, and combat stances.

High Priority
07

Mobile Controls

Virtual joystick and HUD buttons for iOS/Android. Unity Input System with touch profile. 60fps mobile optimization.

Low Priority
08

Save System

JSON-based save files for player position, money, wanted level, and mission progress. Cloud sync via Unity Gaming Services.

Medium Priority

Ready to build your open world?