This paper will present a version of failure theory suitable for designing optimal compliant mechanisms. The resulting theory will be incorporated as design objective functions within a multi-objective optimizing engine with the purpose of producing optimal and robust compliant mechanisms suitable for manufacture. Combining these failure-based objective functions with the classical ones measuring efficiency in performing a task, in the context of diversity promoting multiobjective optimization (see [1]) will demonstrate the tool’s ability to produce optimal compliant mechanisms that are failure-proof as well as provide insights into the complexity of particular design problems.Copyright © 2007 by ASME