That said, I've been thinking about this on and off for a while and I've compiled a lost of neat additions that I've come up with, or found, and which I think could help bring back some specialist appeal. Thoughts and comments are most welcome, naturally!
Feat: Forbidden Magic
This is a pretty basic feat, or at least it's easy to explain, though it might be incredibly complicated to code (I have no idea), but it would essentially be a metamagic feat that would give the specialist the ability to cast spells from their opposed school(s). It would have to have a pretty high cost, I'm thinking, so maybe spells cast with it would occupy slots four or five levels higher than normal.
This basically doesn't have any precedent in FR stuff that I've ever seen, but I think it might nonetheless be appropriate for the MUD. Obviously the restriction of coding and etc. makes it very difficult to have a spell selection that competes with what you could find in tabletop, and I think that the restrictions should take that into account. This would basically be a step towards relaxing those restrictions, but it would also take away from the (negative) 'uniqueness' of specialty wizards.
Feat: Forbidden Spell
This is almost exactly the same as the previous feat, except it's a much more restricted version of it. It would give the caster the ability to learn any one spell from their restricted spell school every time it's taken. The feat could also be restricted to only work on spells under a certain spell level, too.
Feat: Extend Metamagic
This feat would give the specialist mage the ability to apply metamagic feats to their specialist spells at one spell level lower than they would normally cost. Ie. An invoker could cast a twinned version of chain lightning as a level nine spell.
Feat: Spell Swap
This feat would enable a specialist to use his specialist school slot to 'spontaneously' cast any of his school spells, like a bard or a sorcerer. So, for instance, an invoker could use his 3rd level specialist slot to cast fireball, or he could spontaneously swap it out for lightning bolt, as the situation demanded. Obviously, he'd be unable to swap it out for any spell outside of his school.
Specialist Spell School Feats
Abjuration
Dismissive Aura
You can generate a magical field of abjurative resonance that interferes with the energies that bind extradimensional creatures to the Prime Material Plane.
Prerequisites: Spell focus (Abjuration), Caster Level 7+
Benefit: As a standard action that does not provoke an attack of opportunity, you can call into existence an invisible field of energy in a 15-foot burst around yourself. This field detects as abjuration and is always considered a 'strong' source of magic. Any extradimensional creature that enters this field feels immediately uncomfortable and suffers a penalty to its Will saves equal to your charisma modifier (to a minimum of +1) for as long as it remains.
In addition, this field automatically counts as an object hated or feared by any extradimensional creature within its boundaries for the purposes of a banishment spell. Dismissive aura can be maintained for up to 1 minute per caster level at a time, does not require concentration, and the caster must wait at least one hour between uses.
Conjuration
Augment Summoning
Your summoned creatures are better than normal.
Prerequisites: Spellcaster level 2nd+
Benefit: Creatures you summon with any summoning spell are slightly enhanced. They gain one more die of hit points (but they are not treated as +1 HD creatures) and a +1 competence bonus on their attack and damage rolls.
(That's as written, but I might suggest making it a little better than this. Maybe if they came with something like bull's strength on them, or armour, or even stone skin?)
Evocation
Energy Substitution
You can modify a spell that uses one type of energy to use another type of energy.
Prerequisite: Any other metamagic feat, 5 ranks in knowledge (arcana)
Benefit: Choose one type of energy: acid, cold, electricity, fire, or sonic. You can modify any spell with an energy designator to use the chosen type of energy instead. A substituted spell works normally in all respects, except that the type of damage dealt changes. For instance, an acidic fireball still deals damage in a 20-foot spread, except that it is acid damage instead of fire.
If a spell has a secondary effect, the altered spell still has that effect. For example, a shout spell can deafen creatures and deals extra damage to crystalline creatures; if fire is substituted for sonic energy in a shout spell, creatures can still be deafened and crystalline creatures still suffer extra damage. Sometimes a spell's minor effects are directly related to the spell's energy, for example, a flaming sphere can set items afire, but a purely sonic or acidic flaming sphere does not.
When a spell deals some damage that does not come from energy, energy substitution does not affect that portion. For example, ice storm deals 3d6 points of impact damage and 2d6 points of cold damage. An electrical ice storm deals 3d6 points of impact damage and 2d6 points of electricity damage.
A substituted spell uses a spell slot zero levels higher than (the same as) the spell's actual level.
Special: You can gain this feat multiple times, each time applying it to a different type of energy.
Enchanter
Spirit Singer
Through practice and study, you have learned how to work magic that influences the minds of undead creatures, such as zombies and vampires.
Prerequisite: Caster level 7th+, Spell Focus (Enchantment)
Benefit: Your spells from the enchantment school affect all undead as per the spell descriptions. Undead creatures are usually mindless drones or too seeped in negative energy to suffer the effects of mind-influencing spells. Your magic is tinged with energy derived from your understanding of enchantments, allowing you to affect undead creatures. You ignore the undead immunity to mind-influencing affects with enchantment spells you cast. They are still immune to mind-influencing effects caused by magic items or special abilities you wield.
Machine Master
You have studied the workings of constructs, such as animated items and golems, and have learned secrets of affecting their sentient, arcane minds with enchantment spells.
(Everything else is basically the same as the Spirit Singer feat)
Transmutation
Craft Golem
I'm kinda sketchy on this idea, because it seems pretty complicated. However, I think it'd be pretty darn neat to give transmuters the ability to take refined metal and turn it into a golem, maybe with size/strength determined by the quantity of metal used and the level of the mage. Something like a level 10 transmuter using 3 pieces of copper to make a small crude copper golem, vs. a level 50 transmuter using 20 pieces of platinum to make a huge exquisitely crafted platinum golem. Quality could determine the stats of the creature.
(As an aside, transmuters seem to get hammered more than anyone by the spell restrictions, losing, as I understand it, two school instead of one, including super useful spells like stone skin and dispel magic, so unless that's changed giving them a really cool feat might well be in order
)Necromancy
Channel Negative Energy
This is a feat of my own imagining, so it doesn't have nearly as elaborate a description, but it would basically act like a negative energy version of a paladin's lay on hands spell. It could be used to channel negative energy into undead minions to heal them.
Illusion
Alter Voice
I'm not sure if this would be useful enough to stand up to the other feats, but from where I'm sitting, it looks like it might be! Basically, it would allow the illusionist to use the spell 'Ventriloquism' as a special ability as many times as they like, at their spell level. This would let them use it to carry on long conversations, swap out as they like, etc. So it definitely seems handy when trying to create a convincing illusion. Also, it could be used for gnomish puppet shows, and that's just cool
Anyways, that's all I can think of at the moment. I realise that some of these suggestions may not look look entirely feasible, at least without being a lot more fleshed out (ie. golems), or are weaker than the rest (ie. the alter voice feat), but I'm hoping that they might at least spark up some conversation and get some sort of snowball of fabulous suggestions rolling
Thanks for your time in reading this, folks!