The chameleon could be like camouflage power, and invisibility could be like a higher camouflage power, until an action, but those powers could be countered by sight power and keenness of the opposition.
Those power could be added to sneak power, the coloring of worn gear, and environmental effects like ambient light and fog, and so on...
Something like this:
Sneaker:
Sneak skill + Camouflage spells + Worn gear + Environmental effects + Action
Opposition:
Keenness + Blindness or Detect spells + Alarm state + Line of Sight
Environmental effect is the ambient light of the point where the stalker resides, and the fog effect and the like.
The Alarm state can be like this:
- Unconscious: Can not detect anything. :sleep2:
- Distracted: Attention caught by something else. :violin:
- Unaware: Idle, whistling, mumbling and the like... :whistling:
- Alarm level 1: Heard a sound, and looks toward the direction. :shifty:
- Alarm level 2: Saw a something and comes looking for it. :stare:
- Alarm level 3: Find something bad like a corpse and start actively searching. oo:
- Alarm level 4: Found the target but lost it and looking for it. :flame:
- Alarm level 5: Actively pursuing/atacking the target. :gun:
- Alarm level ?: Fleeing from the target. :bolt:
And each alarm state affects the sight power or keenness of the pursuer, so at first it would be easier to avoid them, but if you knock something down and make a noise, it would become harder to avoid them.
This way, you could cast a chameleon spell and pass the regular foes, but those higher level guards and bosses, should be harder to avoid, because they had keener senses, and thus obtaining a high level item, at high level area, that would have higher level foes, would require better spells and more advanced sneak skills, and that would mean higher level player, which would prevent the problem that was my concern.
I.e. using an easy to gain invisibility spell and getting higher level items in higher level areas easily.