[From my post on http://us.battle.net/d3/en/forum/topic/6201700441]
PROS of D2 Skill System:
1. Much less gear dependence.
In Diablo 3, every skill does damage based on your gear. This is a fact. In Diablo 2, you can walk around naked, but your level 20 Frozen Orb will still flatten legions of hellspawn (albeit maybe not as efficiently). But if you try to walk around naked in Diablo 3, you will get 1-shot by zombies and do no damage. This leads to the feeling in Diablo 3 that your character is innately weak, while in Diablo 2, your character is innately strong.
2. Items add choice, not just damage.
In Diablo 2, you could build a Fire/Ice hybrid Sorc and not have Energy Shield, but get Energy Shield from an item. So you can make a real and interesting gear choice like “Do I want gear with +Fire/Ice to boost my damage or do I want an Energy Shield for defense?” Not a bland gear choice like “Do I want 1799 int and 842 resists or 1826 int and 814 resists?” There are probably a hundred other examples I could use within D2’s interesting item affixes.
3. Synergies add complexity.
Take Freezing Arrow for example:
Leveling Freezing Arrow: +cold damage, + attack rating, but also +mana cost
Leveling Cold Arrow (synergy): +% cold damage to Freezing Arrow
Leveling Ice Arrow (synergy): +freeze duration to Freezing Arrow
While I’m not saying that the synergy skills are always worth it to level, or that there are that many viable builds, I am saying that the potential for interesting complexities exists. For instance, if I wanted to make my Freezing Arrow stronger but with my current gear I am extremely starved on mana, I could level Cold Arrow to increase the damage of Freezing Arrow without increasing its mana cost. Granted, you could just spam mana potions, but at least an interesting interaction is going on.
In Diablo 3, the only “synergies” that boost other skills are currently the ones that remove diversity by taking up a skill slot. Want to make your Blizzard/Hydra more powerful? Use Magic Weapon! Even more powerful? Use Familiar with Sparkflint! More survivability? Energy Armor and Teleport! Do you see the problem here? You took up 4 skill slots just to make your other 2 more effective in combat. The same can be said of most other Wizard builds. Some combination of Magic Weapon, Familiar, Energy Armor, and Teleport are in every Inferno Wizard build.
4. Character personality and diversity.
In Diablo 2, builds could feel completely different. Javazon vs Bowazon. It’s like playing a different class. Summonmancer vs Poisonmancer. Etc.
As stated in point #3, this is not true for Diablo 3. A Blizzard/Hydra Wizard in Diablo 3 feels almost the same as a Disintegrate/Archon Wizard, because the other 4 skills will likely be the same (Magic Weapon, Familiar, Energy Armor, and Teleport), with maybe 1 difference.
CONS:
1. Permanence
I played D2 long before the patch that added in respecs, so skills were permanent. This was terrible because you could waste many hours on leveling a character with a build that is flat-out not viable in Hell. Example: Skelemancer. This was my first character, and I was beyond frustrated when I first got to Hell, when I couldn’t kill anything. I was forced to roll a new character.
In D3, the respec feature is great.
2. Useless Prereqs
Though with synergies, this wasn’t much of an issue.
Analysis: How to Improve Diablo 3’s Skill System
Usually when you design a new system, such as Diablo 3’s skill system, you want to keep the pros of the previous system (D2’s skill system) while eliminating or mitigating its cons.
Diablo 3 successfully negated 2 cons of the Diablo 2 skill system as mentioned above. However, it failed to keep any of the pros.
I am going to go through each of the pros once again, but explain a solution in each case that implements it in Diablo 3.
1. Much less gear dependence.
This is simple. The current problem is that the ratio of Stats From Gear to Stats On Character is too damn high. If you took off all your gear besides your weapon, you would be dealing 10-30 times less damage. For instance, a Monk might have 200 base dex, but 2000 dex from gear.
Since this is merely a number issue, the way to fix it is either:
* Nerf gear
* Buff base stats
Many people would get mad if their gear were nerfed, so it would have to be a buff of the base stats. A Monk should have at least 1000 base Dex at level 60. Same with a Wizard having 1000 base int, or a Barbarian having 1000 base strength.
To really make it feel like D2, 1000 base primary stats would not be enough. You would need 2000 to match the gear. But that might seem a bit extreme, so 1000 is a good base for now.
2. Items add choice, not just damage.
This can actually be fixed simply by adding more variety to item affixes. More on-hit procs that cause certain spells to occur, or more +20% damage to X spell (instead of +2% damage to X spell), will help solve this problem.
3. Synergies add complexity.
Now we get to the complex part. There is no obvious way to add synergies to D3 skills, since we don’t level them anymore. However, there is a solution I can think of. Consider each skill at level 0 if not in your build, and 1 if it is.
Certain skill combos could have synergies. For instance, if you take both Blizzard and Ice Armor, then Blizzard gains +30% damage. This would make the player make a meaningful choice between “Do I want Energy Armor for survivability or Ice Armor for synergy with Blizzard?”
This would take a lot of time to design due to the sheer number of skill combos and synergies, and knowing Blizzard, if they ever were to do this, it would be in an expansion. However, we can drastically reduce the number of individual skill synergies we need to design, with the following, radical idea:
4. Character personality and diversity.
That idea, which knocks out #3 and #4 with one stone, is a skill set system. It basically works like item sets: If you have N items in a particular item set, you gain the N-set bonus. Similarly, if you choose N skills from a particular set, you gain the N-set bonus. This would massively improve the complexity of the skill system, massively increase build diversity, and massively increase character personality.
How would it work? Here’s an example. Say you really liked using Frost and Ice spells on your Wizard and wanted to build a pure Frost Wizard. Right now this is impossible, because giving up Teleport/Energy Armor/Force Weapon/Familiar is too high of a cost. Therefore, I propose that the following skills belong in a set, say the “Freezing Set”:
Wizard Freezing Set
-Blizzard (any rune)
-Frost Nova (any rune)
-Meteor w/Comet
-Hydra w/Frost Hydra
-Ray of Frost (any rune)
-Ice Armor (any rune)
Set Bonuses
(3) All Frost damage increased by 30%.
(4) Reduces Frost damage taken by 75%.
(5) Cannot be Frozen.
(6) All of the Wizard’s Freeze durations are doubled.
Now say you use 3 of the above skills in your build. You gain a “3-set Frost” bonus. With 4 of the skills in your build, you get a “4-set Frost” bonus in addition to that. Etc. Maybe 4 is enough, I don’t know if 5 or 6 is necessary. But this is just for an example.
So if you are using Blizzard, Frost Nova, Comet, Frost Hydra, Ray of Frost, and Ice Armor, you basically become a Frost God. This way, you actually make a meaningful choice: “Do I choose between the survivability or damage of Energy Armor/Magic Weapon, or do I want the freezing power of the Freezing Set?
Note this would also be a unique “build.” Right now I’d argue there is no actually unique build for Wizards, because every build uses some combination of Energy Armor/Magic Weapon/Familiar/Teleport/Diamond Skin. With skill sets added, one Wizard (Freezing) might have completely different abilities than another Wizard (Flaming), which would make characters feel much more personalized. This also makes respec’ing feel like you actually change something fundamental about your character, not just change around 2 skill slots and leave the other 4 alone.
I call this paradigm “Builds, not spells.” We should be playing different builds, not the same build framework with different color animations for our attacks. Right now spells like Energy Armor/Force Weapon/Teleport/Familiar/Diamond Skin for Wizards, and to some degree, War Cry/Battle Rage for Barbarians, Serenity/Breath of Heaven for Monks, Spirit Walk for Witch Doctors, and Smoke Screen/Shadow Power for Demon Hunters, make it so that no build actually feels unique, as they all overlap spells.
Summary:
* D3’s skill system solves a couple big problems of the D2 skill system, but it retains none of the greatness that the D2 system had.
* How to fix: Epic buff to character base stats, more interesting items, and some way of adding synergies to skills and promoting “builds” instead of “spells.”