I presume recation is linked to awareness.
I would have prefered a simple range andaction table so if you move within #" I can react, if you fire within #" I can react etc. vehicles are recated to over greter distances that infantry, sneaking infantry are reacted to over shorter distances.
Similar to Operation Overlord I guess...mmm maybe I will work this up.
maybe a reation cold require a simple test as a prerequisite...