In NWN, the spell schools aren't balanced at all, and and the feats supporting some of these schools are all but worthless. We are looking at spicing up a few of the schools, to help at least make more of the feats worthwhile. I'm posting my suggestions below. I'd like to see other suggestions, as well as any discussion on suggestions made.
I will note, this is my suggestions, not a concensus by the DM's, so nothing is set in stone on any of this. I feel more input will be helpful before we actually do impliment some of this.
Abjuration This school has no offensive spells, so these feats are really not usable as is. I had considered only adding one effect of the other for SF and GSF, but I think that both effects together still shouldn't be a balance issue. Spell Focus: +1 Max level on dispels, +1 spell effect on breaches Greater Spell Focus: +1 Max level on dispels, +1 spell effect on breaches Arcane Defense: +50% duration to Abjurations. (This isn't all protection spells, just those of the abjuration school.)
Conjuration Really, conjuration is a fairly strong school in it's own right, and doesn't need a huge boost. Default Bioware summons are too strong, so we will be modifying them to have shorter durations. (I think 5 rounds/level is what we are considering.) After making those changes, we are looking at making summoner's a viable option.) Spell Focus: +1 max summon Greater Spell Focus: +2 max summon Arcane Defense: No Change
Divination This is a tough one. Feeblemind is the only spell I can come up with that is affected by SF, GSF, and SA. Not only does that mean there is only one spell, it also means it's not a particularly useful spell for it's level. This one can use some spicing up. However, I'd like to keep to the theme of SF and GSF being more offensive in nature with SA being defensive. Spell Focus: +3 Lore Greater Spell Focus: Detect Evil as paladin? Arcane Defense: +50% duration to divinations
Enchantment Definately not in need of any help. I would argue this might be the strongest school in the game. Sleep, Hold Person, Consfusion, and Hold Monster make sure that enchanters have strong DC spells throughout their careers. Spell Focus: No change Greater Spell Focus: No change Arcane Defense: No change
Evocation Definately doesn't need a boost as it has more spells helped by the +DC than I can count. Spell Focus: No change Greater Spell Focus: No Change Arcane Defense: No change
Illusion This has color spray, phantasmal killer, shadow conjuration, and greater shadow conjuration. No need for a boost on this one. People will take it just for Phk. Spell Focus: No Change Greater Spell Focus: No Change Arcane Defense: No Change
Necromancy Although this school already has some very strong spells like fear, slay living, contagion, and others, I still like the idea of allowing it to spice up undead animation as a way to reward necromancers for concentrating on their art. Spell Focus: +1 max animated dead Greater Spel Focus: +1 max animated dead Arcane Defense: No Change
Transmutaion This spell has a few key spells worth taking focus or defense for, so I think it should be left alone. Spell Focus: No Change Greater Spell Focus: No Change Arcane Defense: No Change