To start this story, Laggy was thematically bothered by the fact that there were two special physical classes, and zero special magical classes (I mean calc, but it was practically banned by the JP cost).
So...Laggy spent about 5 hours trying to make Math Skill only useable by Calculator...and failed. It then came down to "can we balance Math Skill?" The answer was "actually probably yeah. I mean, if Math Skill only worked with Shell it would be amazingly crappy, right?"
-Calculator-
* Acquired innate [Teleport 2] and [Non-charge]
* [Gained Exp Up] removed from ability list
* [Move-Get Exp] removed from ability list
* [Move-Get JP] removed from ability list
* [Non-charge] added to ability list
* [Math Skill] now has the following spells (and only these) available:
White Magic ... Cure, Cure2, Reraise, Regen, Protect, Shell, Wall, Esuna
Black Magic ... Fire, Ice, Bolt, Poison
Time Magic ... Haste, Slow, Don't Move, Float, Reflect, Demi
Yin-Yang Magic ... Blind, Pray Faith, Doubt Faith, Zombie, Silence Song, Blind Rage, Confusion Song, Dispel Magic
* JP Cost Changes
... CT: 250 -> 900 JP
... Level: 350 -> 200 JP
... Exp: 300 -> 100 JP
... Height: 250 -> 200 JP
... Prime Number: 300 -> 200 JP
... 4: 400 -> 200 JP
... 3: 600 -> 200 JP
... Distribute: 200 -> 100 JP
... Non-charge: 3000 -> 9999 JP
Right, so let me go over some common abuses of Math Skill. The really common abuse is to use something that you block or absorb and the enemy does not. Holy is an obvious one. But, for instance, Paralyze while blocking Don't Act (with, say, pre-nerf Thief Hat) is another obvious one.
There's two things that really get around this--first of all positive effects like Haste, Reraise, Shell, and really anything that can't be blocked with an accessory (Innocent, for instance). Secondly, effects that aren't total gamewinners (BLIND!!! POISON!!)
So...let's get to individual spells
White Magic ... Cure, Cure2, Reraise, Regen, Protect, Shell, Wall, Esuna
All positive status, for the most part.
Cure2: Frankly in the olden CT5Holy days, you did more healing with your best damage spell than your best healing spell. This was dumb. Hence, a higher cure gets included than the highest available black magic.
Cure3/4: If you're using a White Mage with Math Skill, you should be able to heal more with White Magic than Math Skill. Other than that...frankly Cure4 could be calculable with no particular balance risks >_>.
Raise/Raise2: Would be completely broken. Current best range on revival is 4...this brings it to infinite. Currently you can only revive one person at a time. This brings it up to 6. Currently instant speed revival brings people back at 20% HP at most. This would bring that up to 50% HP.
Reraise: This on the other hand...is really good, but very different from all other revival stuff out there. Also doesn't save you from a steamroll (which old CT5Raise did. "Oh, I'm the last person alive, you say *casts* no I'm not").
Regen, Protect, Shell, Wall, Esuna: Nothing too special.
Black Magic ... Fire, Ice, Bolt, Poison
Frankly, I worry that Fire/Ice/Bolt are way too powerful. They can average 117 damage with a pure damage boosting setup, at pretty normal levels, which...completely smokes guns. All three of them can be blocked/absorbed in one way or another. On the other hand, there may be a temptation with neo-Mathskill not to focus on MA+MAU, at which point their damage becomes more like 50, which pfft...whatever. Also, lots of Chapter 3 enemies (when this would have been most powerful) use White Robes or elemental shields themselves. So...maybe it's okay.
Poison...if you're using a non-MA setup is decent. Kinda competitive with Demi for gravity damage.
Time Magic ... Haste, Slow, Don't Move, Float, Reflect, Demi
Most of these are non-fatal. The most abusive one is Don't Move, which if you felt like doing a party full of Mathskillers and Dancers...yeah that's abusive. If you're just using a Calc in a normal balanced party, however, Don't Move enemies are still plenty dangerous. Whatever, it's not like LFT disables the Quickening; full party strategies being scary = fine.
Stuff that isn't included....
Stop: repeated stop locks down the enemies.
Quick: Nothing could possibly go wrong with Quick, right?
Demi 2: Infinite range "lose 1/4 of your health (less if you're a zodiac)" is...acceptable. Doubling it, though, would be o_O
Meteor: I can't believe we're passing up an opportunity to test the theory "the meteor animation never gets old". ;_;
Blind, Pray Faith, Doubt Faith, Zombie, Silence Song, Blind Rage, Confusion Song, Dispel Magic
Blind, Zombie, Silence Song, Blind Rage, Dispel Magic, Doubt Faith: Whatever/situational.
Pray Faith: Really, really good...but also encourages you to work with a non-mathskiller to get real damage. (Granted, this is another good argument for "we should ban Fire/Ice/Bolt for being too powerful", hmm...on the other hand, I guess there's always Zombie -> Cure2 even if we do ban those, so...I guess testing is called for).
Confusion Song: Probably the nastiest negative status we allowed. But...the enemies will generally knock each other out of confusion pretty fast.
Stuff that wasn't included....
Spell Absorb/Life Drain: Weren't mathskillable originally; stayed consistent.
Paralyze/Sleep/Petrify: See Stop.
Foxbird: On the one hand, you can't block this with your own people. On the other hand, Chicken is very very fatal as a status, and would be the most powerful one we allow which would be obnoxious for trying to keep your own brave up.
* Acquired innate [Teleport 2] and [Non-charge]
Laggy wanted the calc class to be a bit more inherently interesting...so it gained innate non-charge too. (Stats still suck though--seems reasonable).
JP...
CT is the most easily abuseable and works in every fight (whereas height and level require different numbers for different fights and such). Exp sucks. That explains CT 900 and Exp 100 JP respectively. All other abilities can be argued to be learned in nearly any order, so all 200 JP.
Distribute...well Laggy felt costs like 10 JP or 1 JP look weird, and still wouldn't get anyone to use it. No other class makes much sense thematically. Oh well. 100 JP and "in running for worst ability in the game" I guess.
Damage Split stays at 300. Because they're so slow, 300 calc JP is like 600 anyone else JP, which is a reasonable price (Blade Grasp is 700 on a class that's easier to unlock).
Non-Charge...seemed dangerous at 3000, since people have been known to pick up 3000 calc JP fairly sanely (that's about what they used to take to learn the Math Skills); 5000 would probably be very safe, but 9999 was just so comical >_>
unlocks
Back to the old 550/550/350/350 Priest/Wizard/Oracle/Time Mage.