  We argue that some scenarios for the enigmatic supernova (SN) iPTF14hls and
its progenitor require a strong binary interaction. We examine scenarios that
attribute the extra power of iPTF14hls to a magnetar, to a late fallback on to
the neutron star (NS) that launches jets, to an interaction of the ejecta with
a circumstellar matter (CSM), or to a common envelope jets SN (CEJSN). For each
of these four scenarios, we study the crucial process that supplies the extra
energy and conclude that a binary companion to the progenitor must be present.
For the magnetar scenario and late jets we claim that a companion should
spin-up the pre-collapse core, in the ejecta-CSM scenario we find that the
formation of the equatorial CSM requires a companion, and in the CEJSN where a
NS spirals-in inside the giant envelope of the progenitor and launches jets the
strong binary interaction is built-in. We argue that these types of strong
binary interactions make the scenarios rare and explain the enigmatic nature of
iPTF14hls. We further study processes that might accompany the binary
interaction, in particular, the launching of jets before, during and after the
explosion and their observational consequences. We do not consider the
difficulties of the different scenarios and neither do we determine the best
scenario for iPTF14hls. We rather focus on the binary nature of these scenarios
that might as well explain other rare types of SNe.
