  Effective WIMP models are minimal extensions of the standard model that
explain the relic density of dark matter by the ``WIMP miracle.'' In this paper
we consider the phenomenology of effective WIMPs with trilinear couplings to
leptons and a new ``lepton partner'' particle. The observed relic abundance
fixes the strength of the cubic coupling, so the parameters of the models are
defined by the masses of the WIMP and lepton partner particles. This gives a
simple parameter space where collider and direct detection experiments can be
compared under well-defined physical minimality assumptions. The most sensitive
collider probe is the search for leptons + MET, while the most sensitive direct
detection channel is scattering from nuclei arising from loop diagrams.
Collider and direct detection searches are highly complementary: colliders give
the only meaningful constraint when dark matter is its own antiparticle, while
direct detection is generally more sensitive if the dark matter is not its own
antiparticle.
