Hi im kind of new to this forum so correct me if im out of line or posting on wrong place... and your attribute systems is REALLY a nice idea

but it needs some fixing for the first Nickba's ORPG and things to take in considering for the new 2nd game
1. Str attribute gain is really fast compared to the other 2 but in return you "need" it to be faster considering the enemys damage, it could be improved by a higher gain vs higher leveled enemys a "normal" gain vs same or equal leveled while lower leveled enemys means a slower gain (since they impose a much lower threat to your hero even if ur a caster since ye should be able to kill them of fairly fast).
2. Agi it got a kind of nice gain but can be balanced aswell... (In the first game it only gives 2%/kill (with about 50% chance as far as ive seen on killing enemys) while that gain does not really get fair since you will fastly get outdamaged by a necromancer since he can get as much int at any lvl as he likes... (Bugg? i will get back to that later) anyhow a gain of 0.X-1.X% (Depending on mob casters mobs=lowest damage mobs=middle tanker mobs=higest) instead of the flat 2% that the first game uses.
3. Int got the worst system needs LOTS of improvements considering depending on ur class you can end up with an int scoore of "endless" (I'm NOT gonna tell every one who or how you do it! (if Nickba thinks it's ok i'll)) or you really have to work to get your int up by even 1 (Most DPS+Tankers) the idea posted by Goldschakal (mana cost alters the gain) would requier a cooldown+manacost (and some more components iguess) formula to make it fair...
4. Equipment system needs some work to make the your rpg a top class rpg

the system you had in the first game was a really nice solution for it when it was made ^^ but now most other grate rpgs uses custom made systems or more advanced systems (Misc Class Armor pieces/Sets Diffrent Weapons/Shields depending on class or race Dungeons Sets and so on) adding some or all of those elements would really improve the rpgs "roleplay"
5. Items requirements NEEDED since the first game makes you able to purshase the best (shop sold) items from farming low leveled enemys and useing the backpack+hero inventory to sell 12items at the same time resulting in VERY easy ways to get all the cash needed and more... (sellvalue on all items but quest related items? since the gnoll items in the first game can be bought but half of them cannot be sold since they dont have a price...) and adding a tag to quest items *This is a Quest Item for the Quest xxxxxxxxx* or so.
6. Respawn system Goldloss (and possibly xploss if dieing repeatedly or something like that) from dieing or some other way that really makes the player think twice before rushing in and really boosting up the teamwork req

and teaches a more carefull approach to bosses.
7. Save system not including attribute progress?

that coulda be saved aswell right?... woulda be nice if it could atleast ^^ and why doesn't xp save? (the mechanics2 set xp isn't THAT hard... (got no idea of how the save systems works to generate codes alltho so might be harder then you could think/guess)
8. Buggs/Glitches... Those i would prefer takeing privatly since they still exist in the latest "Nickba's ORPG" (If Nickba thinks it's okay i'll post them laters) and they make some chars REALLY imbalanced!!!
9. For the new rpg "Nickba's ORPG II: Cursed Island" (that's atleast what ithink it's gonna be named if i didn't misunderstand Nickbas post about it) those things i've mentioned would be awesome to see fixed/added (atleast considered and hopefully included in some way)
Any questions can be sent in a private msg to me n i'll try to clear any missunderstandings and/or unclear statments that i might have said ^^