Missouri Airsoft and Simulation Site (M.A.S.S.) is an airsoft field and pro shop serving the Kansas City area from its location in Lawson, Missouri. The site occupies a 30-acre property that combines wooded terrain with indoor close-quarters combat areas. Originally a Nike missile site and later a school, the field was developed as Mako Advanced Combat Center before new ownership took over in 2018, renovated the grounds, and established M.A.S.S.

M.A.S.S. hosts public play on Saturdays and Sundays from 9 a.m. to 4 p.m., along with private events and special weekday events. Its pro shop offers airsoft guns for beginners and experienced players, BBs, batteries, accessories, drinks, water, and snacks. The venue also provides a marked field layout and organized gameplay governed by safety and equipment rules, including required eye protection and weapon chronograph checks. Players can contact the site by email or phone for information about visits and events.