A mercenary is a person who takes part in an armed conflict who
is not a national of a Party to the conflict and "is motivated to
take part in the hostilities essentially by the desire for private
gain and, in fact, is promised, by or on behalf of a Party to the
conflict, material compensation substantially in excess of that
promised or paid to combatants of similar ranks and functions in
the armed forces of that Party".[1][2] When the term "mercenary" is
used to refer to a soldier of a national, regular army, it is
usually considered to have pejorative connotations
wikipedia
acording to law the foreign legion are not mercenary. but among
soldier of fortune community they are merc, flesh and bones.
