  We compare tame actions in the category of schemes with torsors in the
category of log schemes endowed with the log flat topology. We prove that
actions underlying log flat torsors are tame. Conversely, starting from a tame
cover of a regular scheme that is an fppf torsor on the complement of a divisor
with normal crossings, it is possible to build a unique log flat torsor that
dominates this cover. In brief, the theory of log flat torsors gives a
canonical approach to the problem of extending torsors into tame covers.
