Collaborative decision-making remains a significant research challenge that is made even more complicated in real-time or tactical problem-contexts. Advances in technology have dramatically assisted the ability for computers and networks to improve the decision-making process (i.e. intelligence, design, and choice). In the intelligence phase of decision making, mixed reality (MxR) has shown a great deal of promise through implementations of simulation and training. However little research has focused on an implementation of MxR to support the entire scope of the decision cycle, let alone collaboratively and in a tactical context. This paper presents a description of the design and initial implementation for the Defense Integrated Collaborative Environment (DICE), an experimental framework for supporting theoretical and empirical research on MxR for tactical decision-making support.