Video games are made by an individual or team of individuals that combine art, sound and story elements using computer code and a game engine. A game engine is the core libraries of code that provide graphics, physics and gameplay control elements for a video game.
The video game development process differs with each individual project. Blockbuster games such as "Call of Duty," "Battlefield," "The Elder Scrolls," "Final Fantasy" and "Halo" require teams of dozens to hundreds of people in size due to the scale of the game environments and development time frames for these franchises. Hobby game developers, students and independent studios that do not have the resources of large studios develop games using commercial game engines such as the Unreal Engine or Unity. Advantages of commercial game engines include reduced development time, included pre-compiled scripts and plug-ins, advanced graphics rendering technology and large communities of developers that offer support.
The Unreal Engine and Unity are free to use with differing limitations on their commercial usage, as of April 2015. Alternatives to more complex 3D engines include drag-and-drop style game making software, such as Scirra Construct 2 or GameMaker: Studio. Drag-and-drop editors allow users with little or no programming knowledge to create complete games with the included game logic and simple programming tools using custom languages or logic bricks.