Looking for some ballancing help

[Taka]

Hi, for last 2 months I have been working on trpg loosely based on dot hack universe (mostly force era) but I have problem with skill ballancing mainly SP cost and cooldown. System on wich it runs is original and uses d6 as primary dice and works (been tested) . Will apriciate any help XD.Combat System as stated works with d6. There are 6 stats. Gameplay tries to emulate video game feel (setting dot hack universe if you know) P-ATK M-ATK P-DEF M-DEF HIT(accuracy) SPEED (evasion) Player also has HP and Sp. Sp doesn't regenerate, restored when next to "platform". In other words GM decides when it regenerates. Spells are mostly taken from original dot hack games. When you attack you roll 3D6+hit stat and compare it to targets rolled 3D6+speed stāt. If you get a pair of numbers it is counted as crítical hit and you get +1D6 to damage roll. Damage formula is 2D6+appropriate ATK stat-targets appropriate def stat. (if casting spell then M-ATK if physical then P-ATK) That more or less sums it up I think. Each class has unique skills that cost Sp and have cooldowns (how many turns you can't use it again). At LV6 and 15 you advance your class (for example twinblade >assassin >flick reaper) choosing 2 skills to keep from previous class.

[aimlessPolymath]

One of the easier ways to eyeball costs is to set a constant rate.

Assumptions:
-Statistically, everyone has equal statistics. Among other factors, this leads to a 50% hit rate. Furthermore, the estimated damage of one damage roll (ignoring crits) is 7.


Let's say 1 SP is worth 1d6 damage (modified by evasion)- this is an estimated 1.75 damage per point of SP. Then the following are equivalent over the long term:

-An attack that costs 1 SP and deals +1d6 damage
-An attack that costs 2 SP and deals +2d6 damage
-An attack that costs X SP and deals +Xd6 damage
-(roughly, after some work on Anydice) An attack that costs 1 SP and has a +2 attack bonus (note that attack bonus costs are not linear)
-An attack that costs 2 SP and hits two enemies



In terms of cooldowns, I have no idea what to do beyond some vague ideas- it seems that

[Taka]

So, for stats they are pre-made for each class so no-one will put all their points into speed and be op. For damage based skills this would work well but what to do with more untraditional skills (for example twinblade has skill second blade that allows you to attack twice in one turn). As for cooldown it's a measure for how many turns that skill will be unavailable to you. Also, the Sp should be put up. About 3 Sp for 1D6.... And thanks for the idea!