Wednesday, October 31, 2007

Derived Stats and Spell Damage

The damage done by a spell or special ability (non-crit) generally takes the form of:

TotalDamage = BaseDamage + Coefficient * PowerStat

For melee attacks and abilities, the PowerStat is Attack Power. For spells, the PowerStat is +damage or +healing.

What's interesting here is that Attack Power (AP) is built into the game from the very beginning. It's a derived stat, meaning that it's value comes from other primary stats. Different classes use different primary stats to boost AP. Warrior, paladins, and shamans boost AP through Strength. Rogues and Hunters boost AP through Agility. Druids use a mixture depending on what form they take.

In contrast, spell damage is tacked on to this system, and only starts appearing at the high levels. Even though it behaves in the same manner as AP, it is not a derived stat, but a completely separate one. It's also different in that it's actually a collection of PowerStats, each boosting a specific spell school.

In my opinion, the Attack Power system works better than the spell damage system. It's simpler and more elegant. Additionally, it works with the five primary stats, and allows different classes to value gear in a different manner. A ring with +Agi means different things to a warrior, a rogue, or a hunter.

It's probably too late for WoW now, but reworking spell damage to mirror Attack Power would have a lot of benefits. Let's call the new PowerStat Spell Power (SP). For example, mages and priests could get Spell Power from Spirit, while warlocks and druids could get Spell Power from Intellect.

This immediately differentiates the classes. You could tweak the rate at which Spirit or Intellect is converted into SP and balance each class without seriously affecting itemization. For example, maybe 1 Spirit = 3 SP for Mages, but 1 Intellect = 2 SP for Warlocks.

The other major advantage comes with paladins and shamans. The melee-magic hybrids. For these two classes you could have Strength convert to Spell Power as well as Attack Power. This would mean that both sides of the class would scale with the same stat.

We don't really need a power stat for each separate school of magic. The only place where it's significantly used for damage spells is the tailoring epic sets. 90% of the other damage gear in the game only uses +damage/healing.

As for +healing, let's pretend that you get twice as much +healing as +spell damage. (It's not exactly twice, but it's pretty close.) So 1 Spell Power = 2 Heal Power. Taking a look at the equation above, we can go:

TotalDamage = BaseDamage + Coefficient * PowerStat
TotalHeal = BaseHeal + Coefficient * ( HP )
TotalHeal = BaseHeal + Coefficient * ( 2 * SP )
TotalHeal = BaseHeal + ( Coefficient * 2 ) * SP

Instead of using a different PowerStat for healing spells, we can use the same PowerStat and simply double the coefficent on healing spells. It accomplishes the exact same thing!

Converting the spell damage system into a mirror of the Attack Power system would accomplish many goals. It would simplify the number of stats on gear. It would allow you to differentiate classes by getting them to place different values on the primary attributes. It makes the primary attributes more valuable for spellcasters. It allows melee-magic hybrids to scale with one stat, rather than chasing two. It causes both offensive and defensive spells for healers to scale at a similar rate, rather than having extremely powerful healers who can't hurt a fly.


  1. Given the changes to weapon skill coming in 2.3, I wouldn't totally discount a change like this.

    Not so sure I like using Int for SP for the other classes though. You could almost get away with 'Strength of will power' as a stat instead.

  2. Strength and Agi don't make sense for warlocks, I want Spirit for Mages, Priests. Stamina would make Warlocks a little too good. So that leaves Int.

    Int is also a good choice because warlocks don't need as high an Int as the other magic classes. They can Lifetap for mana, and don't need as much spell crit, since DoTs don't crit.

    As for druids, honestly, who knows. Maybe they could get SP from multiple stats or something. Maybe Moonkin form uses Int, and Resto form uses Spirit.

  3. Resto druids should get buffs from Spirit (think of what their aura and tree form does, bonus healing based on spirit), likewise for priests. Moonkin should be based off intellect, as should mages, as mana pool is a big issue for them. I would throw warlocks into the spirit group too, they don't need to stack intellect now, and there's no reason to make them start now. Intellect also for resto and elemental shamans, might for warriors and enhancement shamen. I would say agility for rogues and feral druids. Paladins I would also base on spec, might for prot and ret, and int for holy.

  4. Blizzard seems to have realized this error in retrospect. Of course they'll likely try and convince you that "it's not a bug, it's a feature".

    An example of Blizzard more or less directly implementing the kind of thing you're talking about can be found in the 2.3 buff to the Shaman talent, Mental Quickness. For a 3 point investment it's a straight 30% AP->damage conversion. Moonkin and arcane mages have also been benefiting from int->damage for a while, and healing->damage is also coming in 2.3.

    There're still three ugly points though. One is levelling, but nearly three years into the game that's become a non-issue. The other two are the spirit stat and hybrids.

    Spirit is just awful. For warlocks, hunters, shaman, and paladins it's next to useless. Among the remaining classes it still faces a basic, flawed design principle: it's a regen stat that relies on NOT casting, while Blizzard continues to design fast-and-furious encounters that make "taking a breather" impractical. Furthermore, regen stats of any kind are given very low priority by DPS casters, and dwarfed universally by raid synergy and consumables.

    Don't get me started on spirit and the mage class, especially the changes in 2.3.

    As for hybrids, Blizzard just hasn't given them anything significant yet. Part of their design goal seems to be to be punishing versatility (or perhaps conversely, ONLY buffing specialization). Ironically, they're the ones who could benefit the most from a new system.

  5. > Rogues and Hunters boost AP through Agility. Druids use a mixture depending on what form they take.

    Not quite accurate. Agi and Str both contribute the same amount to AP for Rogues and Hunters so for them both stats make sense. Agi also adds to +crit chance and is of course very important for rogues due to the +dodge that it gives, so I would say Agi has an edge over Str for these classes, but Str can still be used.

    As for the "Spell Damage" stats, I agree that making it a derived stat like AP would make the system more elegant and simple. But it's not going to happen...

  6. The short of it:
    Conceptually the proposed system is IMO probably better, since I like flexibility and choice, but Blizz channeled casters in TBC down the +Spell Damage route, and practically-speaking I don't think that change is viable until the next expansion wipes the gear slate clean.

  7. It seems to me Blizzard have gone the opposite way for melee classes though. Originally melee classes got their AP and crit from strength and agility. The amounts each stat increased AP/crit depended on class.

    It seems to me they had problems balancing gear so instead they bypassed stats and introduced +AP and +crit gear, which affects all classes the same (with regards to AP and crit gained, the value of these in turn depend on class).

  8. As you noted in your blog, the major benefit of the changes you suggest will streamline the stats that melee/magic hybrids desire.

    As far as the "pure" magic classes go, it would require a complete overhaul of itemisation of something that is working fine.

    Int is already tied to mana pool and spell crit. Currently mages balance int with spell damage. Tying it to spell damage to int might run the risk of mages (and to a lesser extent warlocks) running around with massive spell damage, crit as well as mana pool. With careful itemisation and budgeting, this could be avoided, but essentially Blizzard have to spend a lot of time fiddling with items to ensure the current balance it not upset.

    I don't see there to be any point to tying spell damage to spi for mages and locks. Spi will just be seen as X spell damage and its regenerative aspects will still be ignored.

    A better solution to issue would be changing the itemisation budgeting ie. making spell damage cheaper on mail and plate or offering a talent that gives a transfers some stats to others (similar to what shaman's are getting in 2.3). Or you could limit the changes you have suggested to paladins and shamans.

  9. Int already is linked to damage and healing, it just takes a lot of int to get 1 point of damage/healing. What would happen is reduce pure spell damage by whatever amount the new format brings an increase in spell damage.

  10. "Not quite accurate. Agi and Str both contribute the same amount to AP for Rogues and Hunters so for them both stats make sense."

    Specifically, strength gives only melee attack power, whereas agility gives ranged attack power as well. While rogues can use strength for pure attack power, they're more likely to want agility due to crit and dodge. Hunters should not ever want strength, because they do not need melee attack power – they shouldn't be in melee range, and their pet's attack power only scales with the hunter's ranged attack power.

    Personally, I'm a little confused over the direction they're going with spirit as used by mages in 2.3. They change evocation so it's not spirit-based any more, but increase the mana regen from arcane talents? Giving them some way to get spelldamage from spirit would probably help, but it goes directly against what they did to evocate =/

    I hear rumors that they're planning on giving Spirit a complete overhaul with the next expansion. No idea what that might be though. We'll just have to wait for Blizz to clue us in.

  11. While you say that AP is a derived stat... my main is a hunter. Most physical dps classes who are serious about PvE will tell you that the bulk of our AP is no longer from stats.

    Strength does nothing for a hunter but increase his *melee* AP. Which is the same as saying strength does nothing for a hunter.

    The paradigm shifted with 2.0 and they essentially nerfed some of us, most notably hunters, by making Agi give us half the AP and much less crit than previously. Rogues fared pretty well, and warriors got out great with keeping the 1 Str->2AP formula and getting gear with boatloads of strength on it.

    If you look at hunter PvE sets they now look almost exactly like caster sets. Some stats, some Mp5, and raw +AP instead of +SP.

    They claimed to do this for item budget reasons. To progress gear, they were having to put more stats on it which was making dps scale *very* well. So they basically nerfed dps and nerfed out itemization.

    Spirit has practically been replaced by Mp5 as a stat... Although it's still of some use to priests...

    Everything has gone to a stupid (yes, stupid) rating system. weapon rating, defense rating, crit rating, hit rating, resilience rating, expertise rating... who knows what next...

    Between the fact that there are too many different stat/ratings to go on any given piece of gear, and that they keep muddying the itemization by trying to balance a broken Arena (The imbalances in the arena are too numerous to go into)... I don't have high expectations.

    They can design their raid gear to work exactly how they want it now. You have so few options for gear at end game, that they'll give you the spell penetration you need. Holy pally wants more spell crit and +healing on their gear? Tough. Blizz doesn't have to add any.

    Prot pallys want spell damage and +defense on their gear without wasting item budget on Mp5? Too bad, none there, looks like you'll be getting spell damage from you rings and rolling on warrior plate.

  12. I'd agree with you on basic game-design principles. Whether or not Blizzard can/should shoehorn it into the current iteration of WoW is another story.

    There's a number of talents that do accomplish this exact thing, Spirit for Priests, and Intellect for Holy Paladins. But it would be nice to see more of it spread around a bit more. Even if the non-talented versions only give very small returns, say, %5 of Int is +spelldmg, it would be worthwhile.

  13. Personally, I like the five primary attributes, and I think more gear should use them.

    Part of the problem is that balancing gear would have been a lot easier if hunters wore leather, and druids wore mail. Then leather gear would be tailored more towards Agility for it's Power Stat, while Mail would lean to Strength.

    The issue now is if a Mail piece has +Str, it's useless as a scaling piece for hunters. If it has +Agi, it doesn't scale for shaman. So Blizzard puts straight +AP so both classes can scale. A similar effect happens on leather to a lesser degree.

  14. great read. very intriguing suggestions. I do think (hope) that we'll start seeing a migration away from spell damage being such a heavy requirement for us pallies.

  15. I've heard mention of spirit both affecting spell damage passively and doing something with threat. How they plan to work threat in there is beyond me, but really, spirit is a character's willpower. I would love to see it increase spell damage/healing for all classes. Lots of gear would need to be changed, but they're doing that and have done it a couple times already.

    Concerning strength and plate, I was under the impression that warriors/paladins get that conversion due to the amount of itemization plate's high armor value retains compared to the other armor types.

  16. One interesting side effect of there being no stat which directly increases spell damage is that there are few DPS casters for twinks. Since Rogues, (Enhancement) Shamans, (Retribution) Paladins, (Feral) Druids, Hunters, and Warriors are all able to directly increase their damage output, while DPS casters are not easily able to due to the dearth of +spell damage gear in the lower levels. Even after 2.3, it will be very hard for a caster to keep up since:
    A) One of the above classes can get gear or enchants which increase AP or their AP increasing stat. Casters can only get +spell damage
    B) Physical damage classes only need to worry about 2 stats generally speaking: Their AP increasing stat and Stamina. Casters need to worry about what little spell damage they can get, Stamina, and Intellect.

    Healers, while able to benefit from additional +healing, aren't as reliant on it, since heals are pretty big for their level anyway.

  17. Wow does that makes sense. Any chance you/we can start lobbying for this? It could work well as a WotLK "update."