The behavior of strain-softening structures in relation to their overall load-displacement response is examined as a stability problem of the global system. The prototype structure studied is the simple beam under three, four and five-point bend. It is demonstrated that fracture problems do not require geometric or material nonlinearity to produce instability-the size and shape of a structure that fails by fracture are the important factors that control the system. In addition, some geometries, for example the four and five-point-bend beams, may develop different crack configurations such that a bifurcation in the global equilibrium of the structure is possible. Experiments and analyses indicate that size, slenderness, constraint and symmetry of the deformed beam must be considered in predicting the post-failure response.