* Accelerate downwards at a constant rate due to gravity. This means its speed increases as it falls.

* Have no other forces acting on it besides gravity. This is the key factor - air resistance, for example, would make it not truly "free fall."

* Be weightless if you were observing it from within the falling frame of reference. This is because gravity is affecting both the observer and the object equally.

Important Note: In everyday situations, air resistance often has a significant effect on falling objects, so true free fall is rare. But in a vacuum, like on the moon, objects would experience true free fall.