Whether you’re an aspiring game developer taking their first steps into the world of development, or just an avid gamer who likes to keep up with the news, you’ll probably have heard the term “game engine” before. You might even have wondered, “what is a game engine?”, before promptly forgetting about it as some dirty camper shoots you in the digital face.
A game engine is the software skeleton on which a game is built. An engine’s purpose can range from providing basic functions that will save a game developer time, to offering up a full suite of systems and tools that can be used to speed up the game development progress.
Game engines make the development process easier and faster, but there is a trade-off. The more user-friendly a game engine is—that is: the less experience you need to be able to use it—the less control you have over your resources. For example, Game Maker Studio 2 makes it very easy to make 2D games, but it is much more complicated once you move into the realm of 3D. And it is basically impossible to make something of the same quality you could achieve in, say, Unreal Engine.
If, however, you wanted to build your game entirely in Assembly language, you would have almost absolute control over how your game worked… but it would take you a lot longer and require considerably more expertise.
Think of a game engine as an interface between you and the computer. An engine can offer features like cross-platform capabilities, for instance. You, the game developer, would be able to create one instance of your game, and then the game engine would take care of the differences between the various platforms it supports.
How do Game Engines Work?
The exact features of any game engine will vary, but the main components that they consist of are as follows;
- Main Game Logic
- Rendering Engine
- Audio Engine
- Physics Engine
Of course, game engines can (and often do) have more to them than those four aspects. And, no rule says a game engine has to have at least those components. If you are looking at any of the leading players, however, you can expect to find those components and more.
Most engines have their strengths and weaknesses. For example, Godot is very popular among 2D game developers. Unity game engine is an excellent all-round engine with a wealth of resources to help you get started. Unreal can produce AAA quality visuals with ease. You get the idea.
We’re going to take a look at some of the big boys in the game engine… uh… game. Now, I’m only focusing on free engines. There are plenty of options for developers or studios who have money to throw at a commercial license. Still, this post—this website—is aimed squarely at smaller independent game developers. So if you’re wondering why there hasn’t been a mention of CryEngine so far, it’s because there is a monthly fee to use it.
What is Unreal Engine?
Unreal is widely considered to be the top dog when it comes to game engines in the independent and small studio scene if you want those sweet AAA graphics. Made by Epic, this engine has been responsible for some extremely high quality, popular games. Things like Mass Effect 3, Borderlands 2, and Dishonored are all built inside of Unreal Engine.
The licensing situation for Unreal is that you can download and use the engine for free without restriction. If you sell a game made in Unreal, however, they take a 5% royalty.
What is Unity 3D?
Easily the most popular game engine in the indie game dev scene, Unity has some of the most comprehensive resources around for learning how to use the engine. In terms of features, it offers the full gamut. Unfortunately, such a rich feature set leads to some shortcomings.
For example, while it is possible to make a great 2D game in Unity 3D, many developers prefer Godot engine for that style. It is also possible to get some stunning graphics out of Unity, but for AAA visuals, most devs will opt for Unreal. Similarly, as easy as the Unity engine is to learn compared to other comparable engines, it is not as simple to use as Game Maker Studio.
Pricing-wise, Unity operates on a subscription model, with the base tier being free. To be eligible for this tier, you (or your studio) must not have made more than $100k in revenue or funding in the previous twelve months.
What is Godot Engine?
Godot is a much younger engine than Unity or Unreal, and for the most part, it shows. It can’t match those other engines for features, but what it does have going for it is a dedicated 2D engine. In Unity, when you make a 2D game, you are essentially making it in 3D space. That is not the case with Godot, and all the performance benefits that come with that difference are yours for the taking.
In terms of pricing, Godot is an open-source engine. Being open-source, there are no costs involved in using it to make a game or distributing that game when it is done. The only requirement is that a copyright notice is included with your distribution.
What is a Game Engine FAQ
Whenever possible, I like to include a frequently asked questions for those in a hurry who don’t have time for my waffling on. And this post is no different. So here are some of the most commonly asked questions about game engines.
The best game engine for any situation varies depending on what the situation is, but as a general rule, Godot is the best choice for 2D games, Unreal is the best choice for AAA quality games, and Unity is the best all-rounder.
Unreal, Unity, and Godot are all free to use. In the case of Unity and Unreal, there are licensing terms based on your revenue as a game developer. Godot is completely free, however. That being said, always read the current licensing agreement before selling a game.
Game Maker Studio 2 is by far the easiest game engine for beginners to pick up. For those looking to get more involved, however, Unity 3D has the widest selection of resources available for learning.
Open source engines—such Godot, OGRE, and Panada3D—are engines where the source code of the engine itself is publicly available. The licenses on various open source engines can vary, but redistribution and modification is often permitted.