Scion said:
This doesnt follow. As darkness said useing the same logic then darkvision would also negate hide in plain sight, and there is no reason to assume that to be the case.
True seeing does not prevent one from useing this ability, it doesnt even negate it, it has no ability to effect hide.
SRD:
Hide in Plain Sight (Su): A shadowdancer can use the Hide skill even while being observed. As long as she is within 10 feet of some sort of shadow, a shadowdancer can hide herself from view in the open without anything to actually hide behind. She cannot, however, hide in her own shadow.
It doesnt matter if the person can see through the shadow, all that the shadowdancer cares about is that there is a shadow.
All that this ability does is make the character able to use his hide skill in a very strange circumstance. True seeing does nothing about hide. Nor does being able to see through the shadows have any effect.
Again, I agree with most of your points above, namely: Hide in Plain Sight allows a shadowdancer to use the Hide skill while being observed, and
true seeing does nothing about Hide. Neither am I arguing that Hide in Plain Sight works by allowing a shadowdancer to hide in a shadow (he only needs to be within 10 feet of one).
I brought up magical
darkness because it closely parallels how I see Hide in Plain Sight interacting with
true seeing. Suppose a rogue was hiding in an area of magical
darkness. He can make a Hide check because the magical
darkness grants him concealment. He can even hide from creatures with darkvision because darkvision does not pierce magical
darkness. However, against a cleric with
true seeing, the rogue cannot make a Hide check because
true seeing sees through
darkness, and so the rogue would not have the concealment he needs to make a Hide check. The cleric would not automatically see the rogue if there was some mundane source of concealment that the rogue could use - undergrowth or a curtain, for example.
True seeing would not prevent the rogue from making a Hide check if he was normally able to. However, if his only source of concealment was magical
darkness,
true seeing would defeat that and prevent him from making a Hide check (and thus, he would be automatically spotted).
Similarly, with the Shadowdancer, the Hide in Plain Sight ability allows him to hide when he otherwise is not able to. Since it is a supernatural ability, magic is involved, unlike the Ranger's extraordinary Hide in Plain Sight ability. Because magic is involved, it does not work against a cleric with
true seeing. The shadowdancer can still hide normally, and
true seeing will not work against that. However, Hide in Plain Sight is not possible.
Consider this scenario: a rogue is hiding in normal darkness (only - no other source of cover or concealment) 50 feet from a human, an elf and a dwarf carrying a hooded lantern (bright light to 30 feet, shadowy illumination to 60 feet). I would allow the rogue to attempt a Hide check against the human (shadowy illumination to 60 feet), but not the dwarf (darkvision 60 feet) or the elf (low-light vision - bright light to 60 feet). The dwarf and elf would be able to see the rogue regardless of his Hide check because as far as they are concerned, he has no concealment to hide in.
In just the same way that darkvision and low-light vision allow the dwarf and the elf to automatically see the rogue by making the normal darkness irrelevant,
true seeing allows the cleric to see the rogue hiding in magical
darkness by making it irrelevant, and allows him to see the shadowdancer hiding in plain sight by making that ability irrelevant.