The concept of the steric effect in molecular collisions is central to chemistry. In this Perspective article we review some of the progress made in studying the steric effect in inelastic and reactive collisions involving relatively small isolated atomic and molecular species. We overview the theoretical framework used to quantify the steric effect, and outline some of the key experimental approaches that can be employed to study the dynamics and mechanism of collisions involving oriented and aligned molecules. We illustrate the discussion by highlighting a few recent studies of inelastic and reactive scattering. Finally, we conclude with some reflections on possible future directions of interest.