how to create an object that cannot overlap?

I think that adding the following conditions as sub events to on touched batao will fix that (if you delete the action as well/ move it to the sub events)

1)touch.y is greater than or = arvore.y-(arvore.height/2)

1)touch.y is less than or= arvore.y+(arvore.height/2)

A)touch.x greater than arvore.x+(arvore.width/2)----->set acao to 13

B)touch.x less than arvore.x-(arvore.width/2)----->set acao to 13

2)touch.x greater than arvore.x+(arvore.width/2)

2)touch.x less than arvore.x-(arvore.width/2)

A)touch.y is greater than or= arvore.y-(arvore.height/2)-->set acao to 13

B)touch.y is less than or= arvore.y+(arvore.height/2)-->set acao to 13

What I posted checks involves checking the size of the object in relation to the touch positioning (assuming you are primarily concerned with the same objects not overlapping). height/2 makes sure that it is outside of any y that would overlap and width/2 for the x that may overlap. you may actually not want to divide it by 2.... either way, that's how I would go about it.

it may also need to be on the event below. Using the objects height and width within the condition is the simplest way to do it.

another way to do it is to destroy the object that is overlapping at a great z elevation and then set acao to 13 again (or whatever other value needs to be reset)