I'm currently planning a game, and one of the intermediate enemies will be, if possible, a woman with Psychic powers allowing her to vanish.
Does anyone have any good rules for invisible enemies? I'm currently thinking of giving players a -30 per test to identify which square of the combat map she's in, and a -20 or 30 to the BS test to hit her. Other methods of ascertaining what square she's in will be available will be luring her into nearby water, psyniscience (1dos identifies square, 2 removes penalty to BS test), or basically whatever clever method they think of- these negate the perception test but not the BS penalty.
Is that any good?