Contact Interaction Searches at e+e- and e-e- Colliders:. Role of Polarization

We explore the potential of e⁺e^- Linear Collider (LC), operating in the e⁺e^- and e^-e^- modes, to study four-fermion contact interactions in muon pair production, Bhabha scattering and Møller scattering. We stress the role played by the initial state polarization in increasing the reach of this machine in the discovery of new phenomena. Discovery limits are discussed in a model-independent way.