Source can mean anything like an item, feat, class feature, template, magical location, spell, racial trait, domain granted power, etc. from any official material, such as Drow of the Underdark (non-core), Dragon Magazine (not a book), or Wizards of the Coast (WotC) web articles (not print).
A Hide in Plain Sight (HiPS) ability means an ability to Hide (even) while being observed AND/OR without having anything to actually hide behind.
Why I define HiPS as either or both criteria is because, generally speaking, either one sounds like (an ability) to hide in plain sight, and because there doesn't seem to be a prototypical (source of a) HiPS ability. So instead of any ability that is named "Hide in Plain Sight", I define it by the elements that are most common and popular to a HiPS ability.
Because there is no prototype, please be detailed about the HiPS ability that each source grants, such as whether it's extraordinary or supernatural, whether it requires shadow, etc..
If there is something similar enough or better, please mention it too.
Here is an example of several of my points and an example of an answer:
- the Hellbreaker prestige class (Fiendish Codex II: Tyrants of the Nine Hells, p.86) – 1st level
Mantle of Darkness (Ex): You can make Hide checks in any kind of darkness, even when observed by creatures that can see in darkness.
I want to know because I love the thrill of stealth, so I want to know how to get such a valuable stealthy ability.
If you think my question should be amended, please let me know and I will try to accommodate you.
Best Answer
I'll note if the definition says to see another source, but there is disagreement as to what that means.
Here are the sources of a Hide in Plain Sight (HiPS) (or sufficiently HiPS-like) ability:
the Assassin prestige class (Dungeon Master's Guide, p.180) - 8th level, supernatural, even while being observed, within 10 feet of shadow, "can hide himself from view in the open without having anything to actually hide behind. He cannot, however, hide in his own shadow."
the Dark template (ToM161 ...
... or C:TTotW152)
the Blend into Shadows feat (Drow of the Underdark, p.47)
the Eye of Lolth prestige class (Drow of the Underdark, p.80)
the Hellbreaker prestige class (Fiendish Codex II: Tyrants of the Nine Hells, p.86) - 1st level
the Dark Lantern prestige class (Five Nations (Eberron), p.69)
the Lurking Terror prestige class (Libris Mortis: The Book of Undead, p.54) - unaffected by errata
(The rest thanks to Arkhaic)
the Black Dog prestige class (Dragonmarked (Eberron), p.95)
the Luiren Marchwarden prestige class (Shining South (Forgotten Realms), p.35) - 5th level, extraordinary, "within the confines of his march"
the Umbral Disciple prestige class (Magic of Incarnum, p.158)
the Shadowcraft Mage prestige class (Races of Stone, p.120)
the Nightsong Infiltrator prestige class (Complete Adventurer, p.65) - 10th level, extraordinary, natural terrain, unaffected by errata
the Forest Reeve prestige class (Complete Champion, p.82)
the Shadowspy prestige class (Complete Champion, p.105) - 9th level, supernatural, sunlit, unaffected by errata
the Nightmare Terrain spell (Complete Mage, p.111) - unaffected by errata
the Know the Shadows spell (Oriental Adventures, p.107) - unaffected by update or errata
Here are possible alternatives: