preparing fight of mage vs invisible enemies
the group of players including mage has to face a group of opponents lets call them gargoyles who use improved invisibility. how do you treat this? invisibility does not protect against astral perception. but do you have the mage to roll test of astral perception against what? the sneaking skill of gargoyles?
what you as a DM? offer the player to roll this test as soon as he has chance to see the invisible opponent or the player has to guess himself when he has to roll this test?
if they fall to detect invisible enemy does they still have to make reaction+intuition test or they are considered ambushed automatically?