Unreal Engine 1: the engine that made 3D games truly "unreal"

We continue our series of articles about legendary game engines. If Quake Engine laid the foundations for 3D shooters, Unreal Engine 1 was a real breakthrough that launched a new wave of games with stunning graphics, advanced networking technologies, and powerful tools for developers in the 90s and early 2000s. It was a full-fledged platform that opened the door for thousands of creators, allowing them to create large-scale, vibrant worlds and take the industry to a whole new level.

Prerequisites for the appearance of Unreal Engine 1

The world of computer gaming in the mid-90s was on the verge of a major transformation. Pixelated graphics and two-dimensional sprites were increasingly seeming outdated, and the popularity of 3D games was just beginning to gain momentum. It was during this period that Epic MegaGames entered the arena with the ambitious goal of laying the foundation for a new generation of game engines.

An engine is a complex system that provides physics, lighting, AI, animation, audio, network interaction, and much more. And before Unreal Engine 1, most studios were assembling such components individually, which significantly slowed down development and made it difficult to scale projects.

Tim Sweeney, the founder of Epic Games, and his team started developing the engine in 1995 with a clear vision — to create a platform that would be not just a technological solution, but a real ecosystem. The main driver for this was the project of the upcoming Unreal game, which became the first user “demo” of the new engine’s capabilities.

Interestingly, at that time Epic was not yet an industry giant. Most studios focused on specific genres or technologies, while Epic entered the market with the idea of “everything at once”. It was a radical approach that could either lead to a breakthrough or bury the project under the weight of its own ambitions.

All of this was happening against the backdrop of rapidly evolving computer hardware and the emergence of new graphics APIs such as Direct3D and Glide. Unreal Engine 1 made optimal use of hardware acceleration to create detailed, atmospheric worlds accessible to a wide audience.

Unreal Engine 1 and Quake Engine: two 3D revolutions

It’s hard to talk about the world of game engines of the 90s without mentioning two giants — Quake Engine by id Software and Unreal Engine 1 by Epic Games. Both of them became magnets that attracted the attention of developers and players, but they did it in completely different ways.

Quake Engine, created by John Carmack, was a pioneer in full 3D, the first engine to implement a three-dimensional world with polygons instead of pseudo-3D. Its priority was speed, optimization, and minimalism. Quake became famous for its support for multiplayer and smooth gameplay even on rather modest machines of that time. Visually, the engine used basic lighting effects and simple shadows, but compensated for this with a smooth gameplay.

Unreal Engine 1 used BSP to organize space, and the engine offered an improved lighting system, including lightmapping, which allowed for more realistic textures and lighting effects. The support for hardware acceleration was wider, which made it possible to display more complex scenes with higher detail.

Quake Engine, while boasting some extensibility through modifications and plugin support, remained more focused on first-person shooters.

Technical innovations

Unreal Engine 1 was one of the first engines to really raise the bar for 3D graphics in games. Its rendering solutions set the trend that all subsequent generations followed.

Propulsion component	Description	Features and explanations
Rendering Engine	Responsible for visualizing a three-dimensional scene	The engine fully works with 3D polygons, creating a realistic display of objects and landscapes. Supports dynamic lighting with lightmaps and shadows. It is characterized by hardware optimization for Glide and Direct3D.
Audio Engine	Playback of spatial (positional) sound and music	Uses 16-bit stereo sound with 3D positioning support, which changes the soundstage depending on the player’s position, enhancing the immersive effect. It uses DirectSound or OpenAL.
Collision & Physics	Handle collisions, movement, and interaction of objects	Collisions are based on BSP geometry and simple colliders (primitive shapes), which guarantees reliable collision and motion detection without complex physical calculations. Gravity and basic physical interactions are supported.
UnrealScript	Built-in object-oriented scripting language	It allows flexible customization of the game logic without the need to change the engine. Scripts are interpreted in real time, which simplifies the development and modification of the gameplay.
Actor System	System for managing game objects (actors)	Each game object is an actor with a set of properties and behavior. Actors interact with each other through events and messages, which makes the game world highly modular and scalable.
Networking	Networking module	A client-server model with synchronization of actors’ states and events has been implemented. The network code is optimized to minimize latency and traffic, providing a stable multiplayer experience.
Resource Management	Downloading, caching, and managing resources	It supports dynamic loading of textures, models, and sounds from files, with efficient caching, and the output has minimal latency and optimal RAM usage.
Map Format (BSP)	Card format using Binary Space Partitioning	Maps are presented in the form of a BSP tree, which allows you to quickly define visible areas, optimizing rendering and increasing performance, and supports complex three-dimensional structures.
Developer Console	Built-in command and debugging interface	The console allows you to enter commands, configure engine parameters, run tests and cheats without having to restart the game. The tool is actively used by developers and modders.
File System (PAK)	Archive format for packaging resources	The PAK format combines all resources into a single archive, making it easier to deliver, protect, and support modifications. Files can be easily unpacked and replaced by users.

The main feature is lightmapping technology. Instead of the hard shadows that were the norm in the 90s, Unreal was able to create soft, realistic light that didn’t overload the system. This greatly enhanced the atmosphere of game worlds without sacrificing performance.

The architecture of the engine was based on a BSP tree — a simple but effective way to divide the map into rooms and corridors so as not to draw unnecessary things. This made it possible to run complex levels even on far from top-of-the-line hardware at the time. Unreal 1 loved hardware acceleration and supported both Direct3D and the legendary Glide.

Multitexturing, when several layers (dirt, moisture, terrain) are applied to one surface, allowed you to create more lively and detailed worlds — even if real bump mapping was still in the future.

The physics of the engine will not impress a modern player, but for the 90s it was a serious step: falling, gravity, collisions — and all this could be flexibly customized through scripts. Thanks to this, games got unique mechanics without rewriting the engine.

The effects of smoke, fire, and explosions were realized through a particle system optimized for hardware acceleration. This made it possible to create dynamic visual effects without a significant load on the processor.

For mirrored surfaces, Unreal Engine 1 used simplified techniques — mostly special textures and rendering tricks that simulated reflections. Full-fledged rendering of mirror reflections was technically challenging. However, for the time, such effects looked like real magic.

We did not forget about the Skybox. The picture of the sky on the inner walls of the cube made the sky look three-dimensional and alive. And the warp effect — portals through which you can both shoot and pass through, was simply head and shoulders above the competition.

Levels in Unreal 1 consisted of several layers: geometry, textures, light, and scripts that brought the world to life. And all this was done in the built-in UnrealEd editor. Characters moved smoothly thanks to the support of skeletal animation, which added a bit of realism.

Scripting and content development system — UnrealScript

One of the key advantages of Unreal Engine 1 was the integration of its own scripting language — UnrealScript. This was a radical step that brought game development to a new level of flexibility and efficiency.

Before the advent of UnrealScript, most game logic was written directly into the engine in low-level programming languages such as C or C++. This meant long development cycles, a high probability of errors, and difficulty in making changes. UnrealScript made it possible to create game behavior, mechanics, interactions, and events in a separate, more developer-friendly environment.

This opened up great opportunities for modularity and code reuse. For example, a developer could create a basic character class with common properties and then inherit it for different enemies with unique behavior. This approach significantly saved time and simplified code maintenance.

UnrealScript supported events and timers, which made it possible to customize triggers, activation of animations, interaction with the player, and complex NPC behavior. All this made games based on Unreal Engine much more lively and interactive.

Thanks to UnrealScript, it became possible to involve not only programmers but also designers and scriptwriters in development, who could write the logic of game events without resorting to complex code. This made game development a more collaborative and creative process.

Cliff Bleszinski is a name that is firmly etched in the history of the gaming industry. He knew how to combine elements of action and tactics, creating a balance between open areas for large-scale shootouts and narrow passages that forced the player to use tricks and ingenuity.

It is also worth noting that UnrealScript laid the foundation for further developments — in subsequent versions of the engine, this language has evolved, retaining key principles that are still used in many game projects today.

Network capabilities and multiplayer Unreal Engine 1

In the era of the late 90s, when the Internet was beginning to actively enter everyday life, online games became one of the most powerful drivers of the industry. Unreal Engine 1 immediately focused on supporting multiplayer modes, which has become one of its distinctive features.

Technically, the engine had a developed network synchronization system that allowed efficient transmission of game events between clients and the server. This was critical for shooters, where delays of even milliseconds could affect the gameplay.

Unreal Engine 1 supported both classic peer-to-peer models and more reliable server architectures, which made it possible to create a variety of multiplayer modes: from cooperative campaigns to deathmatch.

Of particular importance was the object state replication system — it was responsible for ensuring that all game participants saw the synchronized state of the world, even at different connection speeds. Unreal Engine 1 did this very efficiently, minimizing traffic consumption.

Developers received a ready-made set of tools for creating servers, managing sessions, and handling events, which reduced the time and effort required to implement network functions in their games. And Unreal Tournament became the benchmark for online shooters.

Importantly, the engine could integrate voice chat and internal communication systems, which was a fairly advanced solution at the time. Advanced documentation and examples of network code made Unreal Engine 1 an attractive choice for developers who wanted to focus on online gaming.

Engine licensing and the impact on the industry

Epic Games was the first to offer other studios the opportunity to legally use its engine for a fee, an approach that is now an industry standard but was revolutionary at the time.

Before the Unreal Engine, most studios had to build engines from scratch or adapt limited solutions, which significantly increased the time and resources required. Epic offered a ready-made, proven toolkit that could be used in different genres and for different platforms.

Licensing contributed to the standardization of gaming technologies. Many studios, working on Unreal Engine 1, shared their best practices, experience, and even content, which accelerated innovation. It was Epic’s licensing policy that became the prototype for future versions of Unreal Engine, which eventually became one of the largest platforms in the world of gaming and interactive media.

It’s also worth noting that this policy encouraged other companies to develop their own engines with similar distribution models, creating healthy competition in the gaming technology market.

For example, id Software, known for its Quake Engine, developed its engines and also began to offer them as a licensed product for other developers. Valve Corporation with its Source engine, which was an evolution of GoldSrc, emphasized multiplayer and openness, becoming popular among indie studios. Crytek with CryEngine, starting in the 2000s, offered an engine with powerful graphics and physics, which also expanded the choice for developers.

The legacy of Unreal Engine 1

First of all, it was Unreal Engine 1 that pioneered the idea of a comprehensive game development platform, combining graphics, physics, AI, networking, and a powerful set of tools for content creators. This concept has become a model for future engines, including modern ones Unreal Engine 4 and 5that dominate the market today.

Architectural solutions such as modularity, support for scripting languages, and customization flexibility made it possible to adapt the engine to a wide variety of genres and platforms, which is one of the reasons for its popularity and long life cycle.

Development tools such as UnrealEd and UnrealScript established a tradition of openness and creative freedom that is actively supported and developed in modern versions of the engine. Equally important is the cultural heritage — the community of developers and players that formed around Unreal Engine 1 remain active today, continuing the creative traditions and inspiration.

And, of course, Unreal Engine 1 has become a kind of scientific and technological “lighthouse” that has shown how to combine innovations in graphics, programming, and business to create a successful platform.

The most famous games on Unreal Engine 1

The undisputed leader was Unreal (1998) — a fantastic shooter from Epic Games that demonstrated the engine’s capabilities in creating large-scale, detailed worlds with stunning lighting and atmosphere.

In terms of system requirements, at the time of release the game required Windows 95 or 98, the processor could be a Pentium 90 MHz, but a Pentium II with a frequency of 200 MHz or more was recommended for a comfortable game. A minimum of 16 MB of RAM was required, and optimally — 32 MB. The video card had to support Direct3D or Glide (specifically 3dfx Voodoo), which allowed the engine to implement its advanced lighting and detail. The game required about 220 MB of free hard disk space to install.

The next step was to Unreal Tournament (1999)which practically invented the multiplayer arcade shooter genre. Its fast gameplay, wide variety of modes, and excellent online support have made it a favorite of the eSports community.

An important project was Deus Ex (2000) by Ion Storm, which, using a modified Unreal Engine 1, combined elements of shooter, RPG, and stealth games. A well-developed plot and an open-world prototype made it a cult game and a classic of the genre.

In addition, the engine was licensed for such games as Rune (2000) — an action-adventure game inspired by Norse mythology. The game used a modified Unreal Engine 1 and combined melee combat with magical abilities.

Another example was the Clive Barker’s Undying (2001) — an atmospheric horror shooter that was also based on Unreal Engine 1. This game featured an intriguing narrative, intense gameplay, and spectacular visuals that enhanced the overall effect of fear and tension.

Special mention should be made of Harry Potter and the Sorcerer’s Stone (2001) for PC — an adventure game created on a modified version of Unreal Engine 1, which caught the magic hype along with the 2001 movie of the same name. Do you remember this game?

Conclusion

Unreal Engine 1 was a real revolution in the gaming industry of the 90s. The engine not only demonstrated new technical capabilities of 3D graphics, but also changed the approach to game development in general. It opened the door to numerous genres and projects, and its proprietary UnrealScript scripting language was a breakthrough in creating game logic.

The competition with Quake Engine only emphasizes the uniqueness of Epic Games’ idea — to create a full-fledged platform for developers that became the basis for future generations of gaming technologies.

Unreal Engine 1 is the foundation on which the modern gaming industry was built. Its role cannot be overemphasized for anyone who wants to understand how we got to the modern gaming era.