Book excerpt: This report describes the work on a Science and Technology Objective (STO) entitled Virtual Environments for Dismounted Soldier Simulation, Training and Mission Rehearsal. The four-year (Fiscal Year FY 99-FY 02) STO effort was proposed to address a range of U.S. Army future operational capabilities described in U.S. Army Training and Doctrine Command (TRADOC) Pamphlet 525-66 (U.S. Army Training and Doctrine Command, 1997). The STO activities and goals were focused on overcoming critical technological challenges that prevented effective Infantry Soldier simulation. The U.S. Army Research Institute for the Behavioral and Social Sciences (ARI) led a team of both government and industry developers in examining simulation capabilities for industry. The other government partners vent the U.S. Army Simulation, Training, and Instrumentation Command (STRICOM) and the U.S. Army Research Laboratory Human Research and Engineering Directorate (ARL-HRED) and Computational and information Sciences Directorate (ARL-ClSD). Each of the major players had a particular area of interest but all worked together to explore concepts and systems and to recommend directions for further work on training, concept development, and mission rehearsal.