This report describes activities and results from the project "Technical System Duels" dating from 1998 to 2002. Objectives of the project have been to develop models for studies of EW duels and to conduct assessments using these models. The activities in the project have been in the areas: optronics (models and assessment of image generating systems), radar (models and assessment of countermeasure equipment and chaff) and communication (models and assessment of communication warfare and tools for training and education). The Swedish Defense Forces have through the project received access to a well-developed methodology and model knowledge, directly or indirectly from other FOI-projects and the Swedish Defense Forces electronic warfare educational programs. FREKE, TAVAST, ChfDuel, Mfactor and others models have been delivered to officers within the Armed Forces to function as tools for different purposes. The AntView model has been delivered to Swedish Air Force units as an educational tool prior to international operations. Models within EwSim and the Center of Gravity tracker described in the report have a large potential in training facilities.