Almost all video games operate on the principle of redrawing the screen in quick succession in order for the viewer to have a sense of motion, the same way movies or cartoons are displayed. The amount of frames that are shown per second is called the "frame rate". Alternatively, the term "frames per second" is used, or "FPS" for short.
The reason specifically 60 is currently used is because high definition televisions and computer monitors, particularly LCDs, are designed around 60 hertz signals as a common base capability. Standard definition or analogue televisions from the past would be 60 or 50 hertz depending on the region of the world, and so console games of the past had the same target frame rates.
Developers would target 60 fps in their game for a few main reasons.
- If their game contains relatively simple graphics, it would not put much stress on the hardware and therefore be easily capable of running faster than the common 30 fps. Naturally, many 2-dimensional games do not put much stress on console hardware, so most of those games are 60 fps, compared to fully polygonal 3-D games.
- Some game engines have been optimized very well on a given console platform and can handle the graphical needs of a particular game.
- Fluid and precise motion may be preferred or even required for more competitive games, for example those in the fighting genre.
- Compared to 30 fps, 60 is quite fluid to the eye and gives a much more realistic sense of motion for what's happening on the screen.
- It is more accurate with user input such as aiming the player's camera in a game or controlling a cursor of a user interface.
- It takes 16.6 milliseconds to display the next frame at 60 fps, while each frame takes 33.3ms at 30fps, so players can decide and input their next move in extremely competitive situations.
As more graphical objects or effects are added to a game, the demand on the hardware goes up. Developing on fixed hardware with fixed computational power means sacrifices and optimizations have to be made when having frame rate targets:
- In the tight target window of 16 milliseconds, most games will end up toning down or cutting out things that artists have designed.
- Instead of completely removing objects or textures, lots of small detail could be shown only up close to the player or camera to reduce the load on the hardware, but this will introduce obvious texture and object pop-in.
- Many games target 60, but in reality do not manage to stay there while the game is being played. So the result is a loss of fluid motion when the game cannot keep up at 60 during lots of action or when a large environment is being viewed. Such a game could simply be re-designed to be limited at 30 for a consistent sense of motion, or in very rare cases give an option for the user to decide as seen in Skate 2.