  In this paper, we argue that simulation platforms enable a novel type of
embodied spatial reasoning, one facilitated by a formal model of object and
event semantics that renders the continuous quantitative search space of an
open-world, real-time environment tractable. We provide examples for how a
semantically-informed AI system can exploit the precise, numerical information
provided by a game engine to perform qualitative reasoning about objects and
events, facilitate learning novel concepts from data, and communicate with a
human to improve its models and demonstrate its understanding. We argue that
simulation environments, and game engines in particular, bring together many
different notions of "simulation" and many different technologies to provide a
highly-effective platform for developing both AI systems and tools to
experiment in both machine and human intelligence.
