# bound_y var (movable atom)

Source: https://ref.dm-lang.org/atom/movable/var/bound_y
Added in BYOND 490.

### Default value
> 0

> [!deprecated]
> 
> The bound_x/y vars aren't exactly deprecated, but it's preferable to use icon_w/z or pixel_w/z instead. Best practice is to avoid bound_x/y altogether, and use bound_width/height alone to define a bounding box. New behavior simply subtracts bound_x/y from pixel_w/z to mimic the old usage.

This var defines the bottom side of the physical atom's bounding box, in pixels. By default all atoms are assumed to be one tile in physical size.

The bottom edge of the bounding box starts bound_y pixels inward from the bottom edge of the atom's icon (as affected by step_y). A bound_y value of 4 means the atom has 4 pixels of empty space below it.

Example: A 16×16 smiley face centered in a 32×32 icon should have a bound_y value of 8, since there are 8 pixels of empty space below.

### See also
- [icon_z var (atom)](https://ref.dm-lang.org/atom/var/icon_z.md)
- [bound_x var (movable atom)](https://ref.dm-lang.org/atom/movable/var/bound_x.md)
- [bound_width var (movable atom)](https://ref.dm-lang.org/atom/movable/var/bound_width.md)
- [bound_height var (movable atom)](https://ref.dm-lang.org/atom/movable/var/bound_height.md)
- [step_x var (movable atom)](https://ref.dm-lang.org/atom/movable/var/step_x.md)
- [step_y var (movable atom)](https://ref.dm-lang.org/atom/movable/var/step_y.md)
- [locs list var (movable atom)](https://ref.dm-lang.org/atom/movable/var/locs.md)
- [Pixel movement](https://ref.dm-lang.org/notes/pixel-movement.md)