What is a fiduciary duty on a trustee?

A fiduciary duty may arise in a variety of circumstances and is not restricted to any particular relationship. A fiduciary duty has always been imposed on trustees and has been recognized in countless other contexts including that of professional advisor, teacher, corporate director, and partner in business. In Frame v. Smith, 1987 CanLII 74 (SCC), [1987] 2 S.C.R. 99 at p. 136, Wilson J. offered what that court subsequently described as a “rough and ready guide” for the identification of a fiduciary duty by reference to three characteristics: the scope for the exercise of some discretion or power, the capacity to exercise that power or discretion unilaterally so as to affect the beneficiary’s legal or practical interest, and the beneficiary's peculiar vulnerability to the exercise of that discretion or power.