Prediction of ground failure involving earthquake-induced liquefaction of sloped sandy deposits is a major challenge in geomechanics due to the great number of factors that need to be considered such as initial static shear stress, cyclic shear stress, density state, confining pressure, loading conditions etc. This paper briefly describes the triggers (stress conditions) and the consequences (deformation behaviour) for three distinct failure modes that can be produced by an earthquake on sloped ground consisting of loose saturated sand. Such failure mechanisms were observed in the laboratory by performing undrained monotonic and cyclic torsional simple shear tests on Toyoura sand specimens. Most importantly, a practical method for assessing the failure behaviour of sandy-sloped ground undergoing undrained cyclic shearing based on sand failure characteristics observed in the laboratory is also presented. As an example, this method was used to satisfactorily predict slope failure that occurred in Ebigase area (Niigata City, Japan) during the 1964 Niigata earthquake.