The exponentially expanding design potential enabled by additive manufacturing (AM) is, arguably, barely beginning to be explored effectively. We are creating “high-adventure” generative designs by researching, developing and deploying practical metamaterial design tools. An n-material (n>>3) optimized design capability, combined with a suite of possible lattice family combinatorics, can effectively create otherwise infeasible design options: a multi- or graded-material part from a single material AM printer. Techniques to rapidly produce metamaterial homogenizations and insert geometry-matching conformal metamaterial unit cells provide ways to realize the unprecedented designs. Inclusion of affordable uncertainty quantification techniques adds robustness (i.e. protection against the real world) since variations in loads, boundary conditions, and material properties are expected hazards. This culminates in extreme sports for designers: make your own materials, minimize weight, maximize strength, minimize stress, maximize heat transfer, and quickly and effectively explore a myriad of design tradeoffs.