Engineers have long sought to improve mechanical performance and damage tolerance by combining different materials. In this talk, we extend these efforts to the realm of mechanical metamaterials and examine the challenges inherent in designing advanced damage mechanisms. We will focus on structures on the verge of mechanical instability (also known as isostatic or Maxwell lattices), where stress concentrations are dominated by robust topology and geometry-dependent parameters. The damage mechanisms in Maxwell lattices arise from the localization of surface floppy modes and states of self-stress, which can be controlled through topological mechanical polarization related to the unit-cell geometry. By combining different topologically distinct lattices, we will demonstrate how to manipulate the damage path and fracture toughness.