Rules of [Empty]?

[JSL555]

Nearly most thing was test out they have initial direction. But how about [Empty]?
Simplely, make "X is Y". [Y] which transformed from [X] has same direction as [X].
So i test [empty] in 6-8 "Bottleneck" while we cant see direction of [Empty]s.
Just make "empty is rocket" and undo and repeat this. I found the [rocket]s have random directions every times.
So is that [Empty]s don't have initial direction?

Another guess.
Is "empty is swap" a hiden rule? Or is [Empty] on another layer just as "X is float" makes X in float layer?

[18111398]

I think Empty is a special object that has different properties, like Text does. Afaik it seems that it can’t be described in simple rules

[fluffy buny]

EMPTY doesn't seem to exist as an object but rather a means of referring to spaces with no object. therefore there is no data for "X IS Y" to copy over from X to Y, so the game is likely just picking a random direction for objects to face as they're spawned in by "EMPTY IS X"

this is also consistent with how "EMPTY IS PUSH" and "EMPTY IS PULL" do not behave as if "EMPTY IS SWAP", because with either of the former rules in effect, you cannot move onto empty spaces at all if there is no functionally empty object (e.g. the belts in the aforementioned level, which can be walked on but are not EMPTY) in a straight line from where you're facing

[Hempuli]

Yup, Empty refers to empty tiles and since they by definition do not have anything in them, they also don't have a direction, which is why "Empty Is X" has them look in random directions. I might want to change that for consistency reasons, though.

When an object moves to an Empty space, the Empty there disappears. I understand the notion of thinking Empty as having the "Empty Is Swap" rule, but the Empty does not actually move in that situation, it just gets replaced with non-emptiness. Similarly, if Baba is on a patch off Grass and moves onto Empty, the swapping wouldn't make sense because both the Baba and Grass represent non-empty tiles.

[Flap]

Pfiou, it took me while to figure out how empty works, and more precisely "empty is push".
But it was such a pleasure to use it adequately afterward !