How do I prevent this?

Hello how can i stop these windows from going off screen? I mean Item stara window, they have diffrent size dependent from Item rarity.

You can use clamp for that. Assuming the origin of that window is top left.

X = clamp(self.x, 0, viewportWidth-self.width)

Y = clamp(self.y, 0, viewportHeight-self.height)

I dont know if i good understand u, but i create this object on my item:

You can change those formals slightly to use there or just do it in a set position action after the crest action. All the clamp is doing is move the box so that it fits on screen.