Here's the summary of all those other threads:
Editor (Invisible Attack): Combined with Still, Silent, and Eschew Materials, you can blast people from the shadows with impunity. What I mean by that is, if you make no gesture, no sound, and no indication that you are attacking, and the target has no means of detecting the attack, you have effectively fallen under the rules of an invisible attack.
Editor (Punchline): Invisible Spell is so poorly-written that relying on RAW with it is a waste of time. Either you have creatures that are invisible no matter what -- which is ridiculously overpowered for a +0 feat and makes it one of the greatest summoning feats out there (up with Greenbound and Rashemani Elementals) -- or god only knows how it applies. So, What we have here is a situation where every time it is applied to a spell, you have to ask the DM what his opinion is, and just accept it.
Editor (DMs): However, this guide is made for Players and DMs, so simply saying "Ask your DM." is a cop-out. So, I propose the following "guidelines". This is subject to approval each DM, but this is the best that I could come up with.
Editor (Duration): A good metric for determining what exactly turns invisible is how long does the spell last. It is invisible spell, so it stands to reason when the spell ends, so does the invisibility. Spells with an Instantaneous duration are easy to figure out. Everything about the spell is invisible, but the next instant after you cast it, the aftermath is quite visible. So while a spell may create something out of nothing, if the spell has an instant duration, the resulting object is visible.
Editor (Abjuration): They create physical or magical barriers, negate magical or physical abilities, harm trespassers, or even banish the subject of the spell to another plane of existence. if the spell has a duration, the spell would be invisible during that time.
Editor (Conjuration): Some schools call things from other locations, or transport objects from one location to another. Some schools create objects. If the spell merely transports the creature/object, then the transportation has no visual manifestation, but the subject of the transportation is visible. If the spell creates something, then the created object/creature is invisible for as long as the spell is in effect. However, if the object does something to make it visible under the rules of the spell Invisibility (makes an attack), then said object appears.
Editor (Divination): Divinations rarely have any sort of visual manifestation.
Editor (Enchantment): Enchantments normally have no visible manifestation.
Editor (Evocation): Most evocations are instants, but if it has a duration, it would be invisible until the spell expired.
Editor (Necromancy): Anything a necromancy spell creates would be invisible, like a spectral hand. However, if you are animating the dead, the spell is turning an object from one thing to another. The object is subject to the spell, but not a manifestation of the spell. So Animated corpses would not start out invisible.
Editor (Transformation): A spell's special effect would be invisible, like the green ray of a disintegrate spell. The object the transformation targets is the subject of the spell, not the creation of the spell, and would thus be visible.
Editor (Permissive Viewpoint-Invisible Critters): Some believe that if you make/summon a creature using invisible spell, the create is invisible for the duration of the spell, regardless of any attacks the creature does. This is subject to DM approval.
Editor (Permissive Viewpoint-Polymorph): Some DMs believe that if you do an invisible polymorph sub-school spell, you turn into an invisible version of whatever you are trying to turn into. Another viewpoint is that you look the same, but have all the perks of what you wanted to turn into. The editor does not advocate either viewpoint, but includes them for sake of completeness. Check with your DM.
Editor (Extremely Limited Viewpoint): In this viewpoint, only spells that have a effect line can be made invisible. Whatever is on the effect line is made invisible and remains invisible until the spell expires. This limits the number of spells it works on, but does make it rather specific what can be made invisible. Discuss with your DM before taking this feat.
