What about the System? Why we need this system? It's so simple: you have spells - you can cast it.
No, it's a little more complicated and we need a plan. 

I. Requirement: Mana

Let's say we have 2 characters Magе and Warrior and we have one spell - Fireball. Logically, each character can cast thes spell if it has enough magical power. But the Fireball - it is a strong spell, only skilful magicians can cast it. Consequently, this spell should require a lot of mana and Warrior does not have enough mana to cast this skill. Mana - a magical resource, so only magical characters have a lot of this resource.

Therefore, we can divide all Spells it into 3 groups:
1. Powerful magic spells - require a lot of mana.
2. Magic spells - require an average amount of mana.
3. Ordinary spells - require a small amount of mana.

II. Requirement: Weapon

Let's say we have 3 characters Magе, Warrior and Ranger. And we have 3 spells: Onslaught, Explosive Arrow and Arc Beam. These spells are similar to standard skills they have a weapon requirement. You can`t cast Arc Beam using a hammer or a sword.

Therefore Spells are divided into groups:
1. Melee weapon spells.
2. Ranged weapon spells.
3. Magic weapon spells.
4. Greathammer spells.
i.e.
Some spells require a weapon group, some one type of weapon.

Both of these Requirements - Mana and Weapon gives us a flexible control system. It determines which spells chracters should use and will use.

Hi lolesch.  I am glad that we can discuss this interesting theme.

Anyways, have you tried to change the SpellCount in the following menu:
Data Editors - Inventories - Containers - ...spellslot.dat?

Yes, I tried to do it. The problem is that new slots are not working. It was a serious disappointment for me in those days.

The bad news is that the "spell" scroll/tome system is hopelessly hardcoded. The 4-spell limit is unavoidable and no part of the system can really be repurposed for anything else. So, you've pretty much got to do everything some other way.

Second: Some thoughts on your categorization. If every "skill" is a spell - what is the benefit of not investing in magical power? The RPG in here let you decide between Mage and Warrior, will the warrior have stronger "on-Hit" effects so that he will benefit from Ordinary Spells like attackspeed bossts or such?
what I wanted to point out is the old problem of balancing. only a mage might use powerful magic spells but sill can choose all weapons right? So he's able to use ALL spells while the Warrior might only use ordinary spells according to his melee weapon...

Balance is always a compromise. 

Ideally, each "Сlass"(Mage, Warrior, Ranger) will get its own group of Powerful spells. Some spells will be binding to weapons, some are not. Can Mage use all Spells? In theory - yes, but in practice - not.

I tell a little about the Weapons, Requirements and my "Classes".

Each weapon type(Melee, Range and Magic) requires a certain stat.

Hammers/Swords - Strength
Bows/Crossbows/Pistols - Dexterity
Staffs / Wands - Focus
Shields - Vitality

If you do not have the required stat - you can`t use this weapon. For a more powerful weapon, a higher stat is needed. Damage of Weapon Spells depends directly on weapon damage. All this means - for powerful damage, you must have a lot of relevant stat.
Example:
Mage have Strength=10 and can equip Axe which has 20 damage.
Warrior have Strength=100 and can equip Axe which has 200 damage.
Spell "Slash". Cost = 10 Mana(Requires a sword or an axe) Deals 200% weapon damage. As a result Mage deals 40 damage, Warrior - 400. Technically, Mage can use this spell, but in practice - it is useless.

good evening (at least over here)

Balance is always a compromise.

good point! And I totally agree with the path you chose but let me share some more thoughts on that:

Requirements: With other words your spells are less weapon required but Attribute required. Now this feels somehow forced to choose between 3 glasscannon builds with full focus on Str, Dex and Foc (yes you may stack some Vit too, but...)
What I want to point out this time is that my preferred system is more multi-layered. A system with less forced opportunities but still supporting meaningful decision making.
Lets say you wanna play a Necromancer/summoner/pet-build... What weapon, spells and Stats would you give him?
Mages with staves are melee and rely on Vita - so they might not use high dmg spells because of less focus (choosing the "wrong" weapon)?

I tried to leave the hardcoded Attribute and Spell system to a more complex system - similar to TES games like Oblivion. Also I've implemented a levelup system that counts your weapon hits, steps taken, potions drank, spells cast, critical strikes landed and so on to support your own play style. A levelup would require lets say 5 "stacked progressions" (you may level 5 different or 5 times a certain) to unlock "passive skillpoints" improving deficits like a lack of Armor, HP, MP or crits.
This way the player can choose more freely between weapons and play style and all comes up to time spent ingame, no wrong decisions possible. Even if you were a ranger and you find a perfect sword you may change to that and start improving your sword handle - gaining a flat dmg increase for all blade weapons and later change back to a polearm that you already leveled up in the very beginning of your characters journey...

I find myself drifting away towards my own mod... and that wasn't intended! For myself I got a problem with games that force you into directions with small variety. But I might aim for too big steps in my preferred direction.

Still always a pleasure to get some input and rethinking from a different point of view.
Cheerio
lolesch

You might try this:

1. Give ALL of the possible active skills to every character class, with a rank of 1.

2. Create a set of custom stats, one stat per active skill. They should have "saves=true" and default value of 0.

3. Create a hidden looping passive that applies SKILL DISABLE for every active skill with a duration slightly longer than its loop period -- unless that skill's respective stat equals 1.
(I'm not 100% sure in my memory that SKILL DISABLE works on players. If it doesn't SET SKILL COOLDOWN REMAINING would accomplish the same result.)

4. Make your findable-loot consumable items for each skill that set that skill's respective stat to 1 and apply SKILL ENABLE (or SET SKILL COOLDOWN REMAINING to 0 , if you're going that route).

5. If desired, use stat evaluators in the skill-related UI pieces to disable/hide the displays for skills that haven't had their custom stat set to 1 yet.

You could extend this to make it possible to learn skills from any event that can apply EFFECTS on a PC -- for example, you could have a boss hitting you with a skill teach you that skill.

You could also add more logic to the looping passive to make a switchable class system. Store the current class choice in a custom stat, then disable each skill unless that skill's respective stat equals 1 and the current-class-choice stat equals whatever value corresponds to the right class.

You might try this:

Thank you Chthon. I feel we need to create a new topic, where we can write all unrealized interesting concepts and solutions for this. The last 4 years I have seen a lot of interesting. 

Well, I was quite satisfied with the Spell system, but I really want to realize Throwing items - grenades/bombs/Molotov cocktails. I feel that your idea can help me in this.

Ha, so your "passives" are somehow equal to my attributes i guess and the player has some more possibilities then Foc,Dex,Str to choose from.

Well, my "passives" have a long story, I reworked it several times  , and now it works like the standard passives with tier-bonuses.

But before I start there is one last question: when the spell damage output is based on your Stats, why all the other requirements? Fireball on a mage will deal lots of damage while Warriors might use it as an ordinary spell and the other way around.

Well, the Weapon requirement is necessary for technical reasons- Spells for all Weapon types need too many animations. For universal spells is needed a universal animation, for Special spells - special animation. It is much easier to ban spellcasting with an inappropriate weapons, than doing animation for unused spells.
Example: Arc Beam
In theory, you can emit a beam using a sword/hammer/spear maybe even a bow.
Perhaps this is a bit illogical, but it can be implemented. We just need Arc Beam animation for all weapons. But do we really need this? 
Let's say that Weapon Damage Spells - is weapon-logical spells.
Exploding Arrow - for bows.
Seismic Slam - for hammers.
Cleave - for axes and swords.
Frosty Shield - for staves and wands
etc.

Meanwhile your question gave me food for thought...
My plan - to use the Weapon Damage for spells instead of WDPS, but what about the one-handed weapon? In this case, one-handed weapons always lose. 
Maybe cast animations for one-handed weapons should be faster? This could solve the problem, but it does not solve the mana cost problem(you have the same cost, but inflicts different damage).
I need to think about it. 

Mana Cost requirement
Well, it is rather a stimulus to maximize Mana. A player must decide what is more important - Mana or other bonuses. If you have the same mana cost for all similar spells, then Mana just an unnecessary secondary bonus/stat.
For Warrior / Rangers we have low mana cost, Mana is a secondary resource/bonus. You can collect other more useful bonuses - speed, health, armor.
For Mages - big mana cost, Mana  is a main resource/bonus. At first - collect Mana and then think about other bonuses.

In addition, different mana cost shows the difference between the "warriors" and "mages". Ie you're cool Mage and you have a lot of mana - you can use powerful spells or you are weak Mage and you have enough mana - you can`t use powerful spells. 

Mana Cost teaches how to be a Mage - сoncentration, sacrifice and prudence.

Also Exclusive "class" spells - it's an incentive to try different classes.

For spells spread between all classes there might be a 4th category.
Or more simple, a color-system similar to item rarity so you just need to frame the icons.
I'm not sure if that is what you meant by "planing" or if it's more about the spells categorization and graduation..

Yeah, exactly - the color indication. Now it is only a concept, but I used the standard colors:


Red - melee weapon spells
Green - range weapon spells
Blue - magic weapon spells
Purple - universal spells

There is only one funky thing about it, if the player wants to use the spell, they will need to "Right Click" the skill ever time they log in to "Re-Learn" it.

hmm seems like the kind of thing a stat-and-counter setup might be able to help with...

Quote from: RnF on January 23, 2017, 10:54:17 am

Did have a solution for this?

I may have figured something out  

Hey RnF!

Thanks for the suggestion. But I feel that this technology is a bit crude. I do not know, it's convenient and functional. During the game, players will be able to learn, say 50 skills. Without the "forgetting system" is awkward to use.

Quote from: Phanjam on January 23, 2017, 06:16:07 pm

hmm seems like the kind of thing a stat-and-counter setup might be able to help with...

Maybe it would work, but I need to move forward, PJ.  I do not have time to do research in this area. In any case, 4 slots is comfortable and balanced.

It is a bit funky for sure, but probably could be improved.  It is an option if you change your mind

Passives did not work in this manner, they could be split off and kept in the spell slots section so they aren't abused.

Just some more info about this

- A number of uses can be applied to the scrolls.  If it is one, the spell scroll disappears and it is learned temporarily, until the player logs out.  Once they log out, they forget it.

Could be an interesting "temporary" spell system.  It will probably be something I explore more.