Voadam said:
That does not quite work with the mechanics of the spell. In an unmodified invis, you can pick up things, interact with people, make loud noises, and still be invisible whether people know you are there or not. It is the act of attacking (succesfully or not) that breaks it. An unsuccessful wiff that makes no noise still breaks the invisibility, so to work with the spell, the symbolic nature of making an attack is the basis I use for ingame explanations.
Mmadsen did ask for variants as well, though so yours can work it just needs some mechanics to back up your view of how it works. Yours would not work against undead and constructs, as well as being broken by a wider variety of actions (no more taunting people while invisible).
Good points. Maybe then, instead of "clouding someone's mind", it blocks their sense of sight in regard to the invisible person, but the spell would warn them of impending danger or violence, thus breaking the enchantment. This warning could be so simple that the severity of the violent act wouldn't matter whether it were a simple wiff, quick stab, crushing blow, or simple ear flick. So if you do happen to make a lot of noise, someone may know you are there but due to there not being any physical threat, they wouldn't be able to see you.
I think this would allow the person to interact with items rendering them invisible if taken and hidden in a robe or cloak, but still allow them to be found through smell, hearing or touch.
Improved Invisibility would reverse the "warning" sending out thoughts that there is no danger even though the person being attacked would realize that there is. Sort of a mental confusion which invokes the game mechanics for attacking someone who is invisible.
In my original idea, I forgot that you could still be found using the other senses. Oops.