🗺️ Understanding Levels

What is a Level?

Imagine you're building a museum. Each room contains different exhibits—ancient artifacts in one room, modern art in another, dinosaur fossils in a third. The building itself is your project, but each room is a distinct space with its own contents, lighting, and purpose. In Unreal Engine, a Level serves a similar role: it's a self-contained space that holds all the objects, lighting, and environmental elements for a particular scene or area.

When you create a new Unreal project, you always start with at least one level. This is your blank canvas where you'll place 3D objects, set up lighting, add interactive elements, and build your experience. Everything visible in your game at any given moment exists within a level.

What's Inside a Level?

A level contains several types of content, all working together to create your interactive environment:

• Actors: Any object placed in the world—3D models, lights, cameras, sound sources, triggers, and more
• Environment Settings: Lighting configuration, sky atmosphere, fog, and post-process effects that define the scene's mood
• Gameplay Elements: Player start locations, spawn points, navigation meshes, and collision volumes
• World Settings: Level-specific configuration like physics settings, gravity, and game mode rules

File Structure

Levels are saved as files with the .umap extension (short for "Unreal Map"). You'll find them in your project's Content folder, typically organized in a Maps or Levels subfolder. When you open a project, Unreal loads one of these .umap files into the editor, displaying all the actors and settings it contains.

Why Multiple Levels Matter

While you could build an entire game in a single level, there are compelling reasons to split your project into multiple levels:

1. Performance: Loading and rendering everything at once is inefficient. Splitting your world into separate levels means the engine only loads what's currently needed, improving performance and reducing memory usage.
2. Organization: Smaller, focused levels are easier to manage, especially when working with a team. One person can work on the forest level while another builds the cave system.
3. Testing: You can quickly jump to specific areas to test gameplay without navigating through the entire world each time.
4. Variety: Different levels can have completely different aesthetics, lighting, and gameplay styles—think of transitioning from a sunny village to a dark dungeon.

Figure: A typical game project organized into multiple distinct levels

Persistent Levels vs. Streaming Levels

Unreal Engine offers two fundamental approaches to managing levels: persistent levels and streaming levels. Understanding the difference is crucial for building efficient, well-organized projects.

Persistent Levels

A persistent level is the "main" level that remains loaded throughout your game session. Think of it as the foundation or the base layer that's always present. When you create a new Unreal project and open a level, that's a persistent level—it's loaded when the game starts and stays in memory.

Persistent levels typically contain:

• Global Elements: Lighting sources that affect the entire world, like a directional light representing the sun
• Game Logic: Blueprints that manage game state, player progression, or UI elements
• Shared Assets: Objects or settings that need to exist regardless of which area the player is in

In a simple project with just one level, that level is persistent by default. But when you start working with multiple levels, you'll designate one as persistent and load others dynamically around it.

Streaming Levels

A streaming level (also called a "sub-level") is a level that can be loaded or unloaded dynamically during gameplay. This is where Unreal's level system becomes powerful for creating large, complex worlds.

Imagine you're building an open-world game with a city, forest, mountain, and underground dungeon. Loading all four areas simultaneously would consume enormous amounts of memory and slow performance. Instead, you'd use streaming levels:

• The persistent level contains the sky, sun, and overall world settings
• Streaming level 1: The city—loads when the player is nearby
• Streaming level 2: The forest—loads as the player approaches, unloads when they leave
• Streaming level 3: The mountain—loads and unloads based on proximity
• Streaming level 4: The dungeon—loads only when the player enters

Figure: Streaming levels load and unload dynamically based on player location while the persistent level remains constant

When to Use Each Approach

How Streaming Levels Work

When you set up streaming levels, you can control when they load based on several factors:

• Distance-based: Levels load when the player gets within a certain radius and unload when they move away
• Blueprint-triggered: Your game logic explicitly loads or unloads levels in response to events (opening a door, completing a quest, etc.)
• Always loaded: Some streaming levels can be set to load immediately with the persistent level and stay loaded—useful for shared geometry or lighting

Unreal handles the technical complexity of seamlessly blending actors from multiple levels into a single cohesive world. From the player's perspective, it all looks like one continuous environment.

Level Organization Strategies

As your projects grow in complexity, having a clear organizational strategy for your levels becomes essential. Let's explore common patterns used in professional game development.

Strategy 1: Linear Level Progression

This is the simplest approach and works well for games with distinct, sequential stages—think of classic platformers or action games where you progress from Level 1 to Level 2 to Level 3.

Structure:

• MainMenu.umap - The starting point
• Level_01_Tutorial.umap - First playable level
• Level_02_Forest.umap - Second level
• Level_03_Cave.umap - Third level
• Level_04_Boss.umap - Climactic encounter

Pros: Simple to manage, easy to test individual levels, clear progression flow

Cons: Each transition requires loading a new level, less suitable for open-world designs

Figure: Linear level progression with distinct stages

Strategy 2: Hub-and-Spoke

This pattern uses a central "hub" area that connects to multiple separate zones. Think of games like Dark Souls (Firelink Shrine) or Splatoon (Inkopolis Square), where you return to a central location between missions or areas.

Structure:

• Hub_CentralTown.umap - The main persistent level
• Mission_Forest.umap - Accessed from the hub
• Mission_Desert.umap - Accessed from the hub
• Mission_Ruins.umap - Accessed from the hub
• Mission_FinalBoss.umap - Unlocked after completing other missions

Pros: Provides a sense of centralization, easy to add new content, players have a "home base"

Cons: Requires transitions between hub and missions, can feel repetitive if overused

Figure: Hub-and-spoke pattern with a central location connecting to multiple zones

Strategy 3: Open World with Streaming

Modern open-world games use this approach to create vast, seamless environments. A single persistent level contains the overall world settings, and numerous streaming levels represent different regions that load based on player proximity.

Structure:

• World_Persistent.umap - Sky, lighting, global systems
• Region_City_North.umap - Streaming level
• Region_City_South.umap - Streaming level
• Region_Forest_East.umap - Streaming level
• Region_Mountains_West.umap - Streaming level
• Region_Ocean.umap - Streaming level

Pros: Seamless exploration, no loading screens, feels like one continuous world

Cons: More complex to set up, requires careful optimization, harder to test individual areas

Strategy 4: Layered Levels

This advanced technique uses streaming levels not for different locations, but for different layers of the same space. For example:

• Main_Persistent.umap - Base level
• Layer_Geometry.umap - Buildings and landscape (always loaded)
• Layer_Lighting.umap - All light actors (can be swapped for day/night)
• Layer_Props.umap - Decorative objects and details
• Layer_Audio.umap - Ambient sound sources
• Layer_Gameplay.umap - Enemies, pickups, triggers

Pros: Excellent for team collaboration (artists work on geometry, designers on gameplay), easy to swap variations (day/night lighting)

Cons: Requires discipline to maintain separation, can be confusing for beginners

Choosing Your Approach

Which strategy should you use? Consider these factors:

• Project scope: Small games can get away with simple linear progressions; large games need streaming
• Team size: Solo developers might prefer simplicity; teams benefit from layered approaches
• Performance targets: Mobile or VR projects need aggressive streaming to maintain frame rates
• Genre conventions: Platformers often use linear levels; RPGs frequently use hub-and-spoke

Don't be afraid to start simple and evolve your structure as needed. Many projects begin with a single level and add streaming or multiple levels only when performance or organization demands it.

The World Settings Panel

Every level in Unreal Engine has a World Settings panel that controls level-specific configuration. Think of it as the "properties" for the entire level—settings that affect everything within that particular world.

Accessing World Settings

To open the World Settings panel:

1. Open any level in the Unreal Editor
2. In the main toolbar, click Settings (gear icon)
3. Select World Settings from the dropdown

Alternatively, you can access it from the menu bar: Window → World Settings

The World Settings panel typically docks on the right side of the editor, where the Details panel usually appears. You'll see it has multiple collapsible categories with numerous options.

Important World Settings

Let's explore the most commonly used settings you'll encounter:

Game Mode

The GameMode Override setting determines which set of rules and logic applies to this level. Different levels can use different game modes—for example, your main menu might use one game mode, while gameplay levels use another.

• What it does: Defines player classes, HUD, victory conditions, and gameplay rules
• Common use: Setting a custom game mode for this specific level
• Example: Using a "MainMenuGameMode" for your start screen, then a "FPSGameMode" for shooting levels

World Composition

For large open-world projects, the World Composition settings help manage streaming levels and world origin rebasing (a technique to prevent floating-point precision errors in massive worlds).

• What it does: Automatically manages level streaming based on distance and handles coordinate system adjustments
• Common use: Large-scale open worlds that exceed several kilometers
• Example: An MMO-sized world where players can travel vast distances

Physics Settings

You can override global physics settings for this specific level:

• Default Gravity Z: Controls how strong gravity is (default: -980 cm/s², which matches Earth's gravity)
• Global Gravity Z: Applies gravity uniformly across the entire level
• Example use: Creating a moon level with lower gravity (-162 cm/s²) or a zero-gravity space station

Kill Z (Death Plane)

The Kill Z setting defines a height below which actors are automatically destroyed. This prevents players who fall off the world from falling forever.

• What it does: Any actor that falls below this Z-coordinate is destroyed
• Default value: Usually set very low (like -10,000 cm below the world)
• Example use: In a platformer, ensuring players respawn after falling into a pit

Default Reverberation Send

Audio settings that define how sound echoes in this particular level:

• What it does: Controls the acoustic properties of the space (is it echoey like a cathedral, or dampened like a carpeted room?)
• Common use: Different levels have different acoustic characteristics
• Example: A cave level might have high reverb, while an outdoor forest has minimal reverb

Why World Settings Matter

World Settings allow each level to have its own "personality" and behavior. Your tutorial level might have lower gravity to help players learn jumping mechanics. Your boss arena might use a specific game mode with unique rules. Your underwater level might have different physics altogether.

As a beginner, you won't need to adjust most of these settings right away—the defaults work well for typical projects. But knowing they exist helps you understand how Unreal gives you fine-grained control over every aspect of your levels.

Creating and Saving New Levels

Now that you understand what levels are and how they're organized, let's walk through the practical steps of creating and managing levels in Unreal Engine.

Creating a New Level

Unreal Engine provides several ways to create a new level. Here are the most common methods:

Method 1: File Menu (Most Common)

1. In the Unreal Editor, go to File → New Level in the menu bar
2. A dialog box appears with template options:
   • Default: Empty level with basic lighting (directional light, sky atmosphere, fog)
   • Empty Level: Completely blank—no lighting, no sky, nothing
   • VR-Basic: Optimized starting point for VR projects
3. Choose a template and click Create

Method 2: Content Browser

1. Open the Content Browser
2. Navigate to the folder where you want to create the level (typically Content/Maps/)
3. Right-click in an empty space
4. Select Level → Empty Level or Level → Default
5. The new level file appears—give it a meaningful name

This method is useful because it creates the level file directly in your chosen folder, keeping your project organized from the start.

Saving Your Level

After creating or modifying a level, you need to save it. Unreal uses two types of saves:

Save Current Level

• Shortcut: Ctrl + S
• Menu: File → Save Current Level
• What it does: Saves only the currently open level

If this is the first time saving a new level, a dialog appears asking where to save it and what to name it. Choose a descriptive name like Tutorial_Level or Forest_Area_01.

Save All Levels

• Shortcut: Ctrl + Shift + S
• Menu: File → Save All Levels
• What it does: Saves all levels currently loaded (useful when working with streaming levels)

Opening Existing Levels

To open a level you've previously created or one that came with your project:

1. Method 1 (File Menu): Go to File → Open Level, then browse to the .umap file
2. Method 2 (Content Browser): Navigate to your Maps folder, double-click the level's thumbnail
3. Method 3 (Recent Levels): Go to File → Recent Levels to see a list of recently opened levels

When you open a different level, Unreal closes the current one (unless you're working with streaming levels). Any unsaved changes prompt a save dialog.

Level Naming Best Practices

Professional projects use consistent naming conventions. Here are some common patterns:

Avoid generic names like Level1, NewMap, or Untitled. Future-you (and your teammates) will thank you for using clear, descriptive names.

Summary

In this lesson, you've learned the foundational concepts of how Unreal Engine organizes 3D worlds using levels. Let's recap the key points:

Key Takeaways

• 📦 Levels are containers that hold all the objects, lighting, and gameplay elements for a scene or area
• 🏗️ Persistent levels stay loaded at all times, while streaming levels load and unload dynamically
• 🗺️ Organization strategies like linear progression, hub-and-spoke, open-world streaming, and layered levels help structure complex projects
• ⚙️ World Settings control level-specific configuration like game mode, physics, and audio properties
• 💾 Creating and saving levels is straightforward—use descriptive names and save frequently
• 🎯 Different templates (Default vs. Empty) serve different purposes—Default gives you basic lighting, Empty gives you a blank slate

What's Next?

Now that you understand how levels work, the next step is populating them with content. In Lesson 2.2: Actors and Components, you'll learn about the building blocks that go inside levels—the objects, lights, sounds, and gameplay elements that bring your worlds to life.