# fps var (world)

Source: https://ref.dm-lang.org/world/var/fps
Added in BYOND 490.

### Default value
> 10

The value of `world.fps` defines the speed of the world in frames (server ticks) per second. By default this is 10 fps, which is a good speed if all objects move in full tiles. Higher values yield smoother results, but at a cost to performance. Timing of many events may be limited by the system clock, so `fps` values beyond 40 or 50 may cause unwanted effects like jitter even for projects that are not very demanding in terms of performance.

For projects making use of pixel movement, higher `fps` is usually desired. 40 seems to be a good value for general use, but in worlds that have a large number of players, you may wish to lower the value and give players a higher `step_size` per tick instead.

This var exists for convenience; it is calculated by `10 / world.tick_lag`. The value of `world.tick_lag` is actually more accurate, but it is easier to think of world speed in terms of frames per second. The actual tick rate has a resolution of 1 ms.

When reading `world.fps`, the result is always given as a whole number to gloss over rounding error.

If you set `client.tick_lag` or `client.fps` to a value other than 0, you can make the client tick at a different (usually faster) rate.

### See also
- [tick_lag var (world)](https://ref.dm-lang.org/world/var/tick_lag.md)
- [fps var (client)](https://ref.dm-lang.org/client/var/fps.md)
- [Pixel movement](https://ref.dm-lang.org/notes/pixel-movement.md)