  In recent years, it has been widely argued that the duality transformations
of string and M-theory naturally imply the existence of so-called `exotic
branes'---low codimension objects with highly non-perturbative tensions,
scaling as $g_s^{\alpha}$ for $\alpha \leq -3$. We argue that their intimate
link with these duality transformations make them an ideal object of study
using the general framework of Double Field Theory (DFT) and Exceptional Field
Theory (EFT)---collectively referred to as ExFT. Parallel to the theme of
dualities, we also stress that these theories unify known solutions in string-
and M-theory into a single solution under ExFT. We argue that not only is there
a natural unifying description of the lowest codimension objects, many of these
exotic states require this formalism as a consistent supergravity description
does not exist.
