So my question is this... will True Seeing make the entire Illusion School inert against that person? Say an illusion specialist Gnome is about to get into an epic battle vs a Divination specialist Wizard. The Wizard (of course) wins the initiative and casts True Seeing. Is the Gnome screwed?
I wouldnt worry too much, you have more spells you can cast and divination spells generally are useless in combat as well.
It is true that it will prevent the majority of an illusionist spells from working on the diviner though.
So my question is this... will True Seeing make the entire Illusion School inert against that person? Say an illusion specialist Gnome is about to get into an epic battle vs a Divination specialist Wizard. The Wizard (of course) wins the initiative and casts True Seeing. Is the Gnome screwed?
Depends on the Descriptor of the Illusion spell, 'True Seeing sees through the vast majority of illusions granted - such as Invisibility/Blur and so forth. There are seldom if ever, any exclusions from what True Seeing cant defeat - its a powerful spell and always has been. That being said however, there ARE some technical aspects to consider - in another thread I covered the issue of a spell like Nondetection versus spells of the Divination school like See Invisibility/True Seeing, a caster level check is needed to 'pierce' through the illusion if cast on yourself, but not when used against an illusion created in a particular area. Its something at least to use in a spellcasters defense but never a guarantee.
True Seeing is a (Su) ability to some powerful creatures, but to use it as a spell it has some significant drawbacks - a 250gp material component for one, and a spellcaster isnt likely to employ it unless he knows his foe is a known Illusionist or has used some powerful Illusion based spells infront of him.
Unfortunately, it seems that the poor Gnome is in a lot of trouble, especially if he/she didn't prepare Dispel Magic. The two weaknesses of True Seeing are that it can be Dispeled, and that it has expensive components, thus not many will be prepared, hopefully. If you don't have dispel, an Illusion(pattern), like color spray might be helpful to have. I don't think being able to see it as an illusion will help with the clashing colors from the spell. It's unfortunate that the only other Illusion(pattern) are Hypnotic Pattern and spells like that, which are useless in the given situation. Blinding the enemy is your next best bet, because then you can use illusions that fool other senses besides sight.
Unfortunately, it seems that the poor Gnome is in a lot of trouble, especially if he/she didn't prepare Dispel Magic. The two weaknesses of True Seeing are that it can be Dispeled, and that it has expensive components, thus not many will be prepared, hopefully. If you don't have dispel, an Illusion(pattern), like color spray might be helpful to have. I don't think being able to see it as an illusion will help with the clashing colors from the spell. It's unfortunate that the only other Illusion(pattern) are Hypnotic Pattern and spells like that, which are useless in the given situation. Blinding the enemy is your next best bet, because then you can use illusions that fool other senses besides sight.
I came to the same conclusion about pattern spells, also shadow spells can still serve a purpose, and simulacrum.. otherwise it is pretty much all useless to be used directly against the diviner. Though it might still be useful against summons and the like.