  The Hamiltonian dynamics and the canonical covariant formalism for an exotic
action in three dimensions are performed. By working with the complete phase
space, we report a complete Hamiltonian description of the theory such as the
extended action, the extended Hamiltonian, the algebra among the constraints,
the Dirac's brackets and the correct gauge transformations. In addition, we
show that in spite of exotic action and tetrad gravity with a cosmological
constant give rise to the same equations of motion, they are not equivalent, in
fact, we show that their corresponding Dirac's brackets are quite different.
Finally, we construct a gauge invariant symplectic form which in turn
represents a complete Hamiltonian description of the covariant phase space.
