Massively multiplayer online games provide rich contexts for fostering scientific and mathematical thinking and reasoning. We are leveraging these affordances by developing an MMOG, The Radix Endeavor, which integrates STEM practices as core game mechanics. In this poster, we will describe how we are designing the game-play experiences around activities in biology and math content linked to the common core and next generation standards. We hope to generate discussion around (1) designing collaborative problem solving activities (2) using log data to assess players at the individual and group level.