  Our knowledge of planets' orbital dynamics, which was based on Solar System
studies, has been challenged by the diversity of exoplanetary systems.
  Around cool and ultra cool dwarfs, the influence of tides on the orbital and
spin evolution of planets can strongly affect their climate and their capacity
to host surface liquid water.
  We illustrate the role of tides and dynamics with the extreme case of planets
orbiting around brown dwarfs. In multiple planet systems, the eccentricity is
excited by planet-planet interactions. Planets are therefore heated up from the
inside by the tidally-induced friction. This process can heat a habitable zone
planet to such a level that surface liquid water cannot exist.
  We also talk about the newly discovered potentially habitable Earth-sized
planet Kepler-186f. Given the poorly estimated age of the system, the planet
could still be evolving towards synchronization and have a high obliquity or be
pseudo-synchronized with a zero obliquity. These two configurations would have
a different effect on the climate of this planet.
