This is the base of the formula, so it has no attractive qualities yet.
(some ideas for that follow the explanation.)
Formula:
SP= ab+ac-a
(The formula was originally "SP=abc" but I found a flaw, hense the change. What I did was make all TP abilites equal, the original formula favoured only higher TP/Stamina abilites.)
If in a party, every participants SP is calculated together and split evenly.
Also, as of now SP is calculated based on highest level in the party to prevent SP manipulation in the form of having low ranks in your party buffing for exploited SP.
I was also thinking something along the lines of having ranks 5 less then the highest being rounded up to the -5 mark. This would prevent parties from wanting to maintian tight level restrictions. If the highest in a party is rank 26, everyone 20 and under would be rounded up to 21 in order to prevent expliot (This is only in respect to the SP they can gain.)
(a) Difficulty multiplier.
This is based on the enemies difficulty. An even match will yield a multiplier of 10.
The multipliers:
1,2,3,4,5,6,7,8,9,10,12,14,16,18,20,22,24,26,28,30,33,36,39,42,45,48...
If the difficulty of the monster increases the multiplier increases accordingly.
(b) Stamina multiplier.
This is related to the stamina used for the action being calculated. 20% is our base for this multiplier, 20% yields a 1.0 multiplier. 40% 2.0 and 80% a 4.0.
(c) TP Multiplier.
The base for this is 0TP and yields a multiplier of 1.0, every 250TP adds .25 to this value. Therefore, a skill that uses 250TP will give 1.25; a skill 1000tp, 2.0; and 2000tp, 3.0.
(I've kept "b and c" variables linear in order to balance everything and prevent exploits. Difficulty gradually increases to promote tougher battles.)
Now the equation above is "(a x b) + (a x c)- a" equals SP. let's calculate a few actions.
(Gladiator will be used for these examples.)
Light Slash:
(Used on an enemy your level)
SP=(10x1.125)+(10x1.0)-10= 11.25 or 11 SP (after rounding.)
(Used on an enemy five levels below)
SP=(5x1.125)+(5x1.0)-5= 5.625 or 6 SP (I'm just going to show rounded answers from now on.)
(Used on an enemy five levels above)
SP=(20x1.125)+(20x1.0)-20= 23 SP
Light Stab: (For this just answers)
(=)
10 SP
(-5)
5 SP
(+5)
20 SP
Circle Slash:
(=)
(10x2.25)+(10x2.0)-10= 33 SP
(-5)
(5x2.25)+(5x2.0)-5= 16 SP
(+5)
(20x2.25)+(20x2.0)-20= 65 SP
Phalanx: (costs 0 stamina, keep that in mind)
(=)
(10x0)+(10x1.25)-10 = 3 SP
(-5)
1 SP
(+5)
5 SP
Provoke:
(=)
(10x1.875)+(10x1.0)-10= 19 SP
(-5)
9 SP
(+5)
37.5 SP
So there's the basic math, it's balanced straight across the board; favours no enemy, no exploits, no actions.
I should mention, there is no need to balance this system (or at least with everyones help there shouldn't be) once an enemy is given a level, it's balanced right into the equation.
In the area of magic, I need alot more information then I possess. This part is easier left to the devs as they have all this nessasary information. I however would have to do extreme amounts of testing that I just don't have the time for sorry.
Now in the area of ways to add benefit to strategy in battle, a chain bonus for killing enemies quick and maybe some sort of effect bonus.
I think a bonus to AOE attacks would be a nice addtion as well.
Chain bonus could be a multiplier given to the basic attacks that ever so slightly increases as the bonus gets higher. Or as a lump sum given at the end of each battle.
Effect bonus could be a way to give bonus to criticals and reduce SP if attacks are resisted or blocked.
Normal unresisted blow could be 1.0 muliplier,
A critical hit 1.25 muliplier.
Half resisted 0.5 muliplier
quarter resisted 0.25.
If you power up attacks and they do above and beyond what's expected, there could be a bonus to that as well.
Raging strikes 50% damage to the attack, therefore recieves a 1.5 muliplier to SP.
An attack like phalanx for instance that is a counter attack in nature and very powerfull at that can recieve a muliplier as a bonus. Phalanx does about 4x the damage of a normal attack, so could recieve a 4.0 mulitplier.
For AOE's
Only Attack AOE's would recieve a bonus, we cannot do cures, buffs or debuff because people will exploit them.
This could easily be done by just having every connection give it's alloted SP.