https://www.ufopaedia.org/index.php?title=Ruleset_Reference_%28OpenXcom%29maxRange Maximum range at which this weapon can operate. default : 200
aimRange Maximum effective range with this weapon before which range-based dropoff occurs. default : 200
snapRange Maximum effective range with snap shot before which range-based dropoff occurs. (ufoextender accuracy only) default : 15
autoRange Maximum effective range with auto shot before which range-based dropoff occurs. (ufoextender accuracy only) default : 7
minRange Range-based dropoff will work in reverse for ranges below this. default : 0
dropoff The value by which the accuracy lowers for each tile after (or before) the thresholds above. default : 2
Whenever a ruleset entry omits a value, it inherits the default.
sneaky AI : not that i know off, sorry.