In Mods before 16, the general rule of thumb for PvE defensive stats was that
- HP was the most consistent stat with no frills
- Defense/damage resistance gets better as you stack more of it (I recall 25,000 or more of stat investment was where Defense equals, or gets better than HP as a Defensive stat investment)
- Deflect was the ugly duckling for not being consistent enough for the same stat investment sans specific dungeon debuffs (I could invest 40,000 Deflect to guaranteed I always take 50% of incoming damage/25% of incoming damage as TR or I could invest 40,000 Defense to guarantee I always take 20% of incoming damage... oh wait...).
While I know it early to speculate what will happen based off of the devblogs presented, I think the dev blogs gave us enough information to piece together an unbalanced trend for defensive stats. PvEwise, HP is over-incentivized to stack over all other defensive stats due to the comparative investment.
If you are wondering how I came to my conclusions, I drew up the following Desmos graph based primarily off of @micky1p00
's Effective HP formulas on her site.https://www.desmos.com/calculator/hhxbxxk3qt
The short reason why is because PvE enemy counter defensive stats are way too high for the investment needed to make the stat useful
HP still remains the consistent jack of all trades stat that is simple with no frills. Fine.
Deflect always loses out because of the luck based aspect and the 50% chance cap: it simply isn't consistent enough and doesn't provide enough defensive measures to be worth the investment (yes, even assuming TR's 75% Deflect Severity). Even if you assumed no counter stat, you would be better off with Defense as usual (and I highly doubt any enemies will lack counter stats). Deflect has always been the implied inverse to Crits (a lucky chance to take less damage), so it's reasonable to assume that you won't have 100% Deflect (like not having 100% Crit Chance), so let's compare defense to HP.
Defense remains as the high investment higher reward stat, fine. If you assume no counter stats, Defense actually beats HP at any investment greater than 12500.
But no counter stats is unrealistic, as this
devblog, the devs stated the all the first zone of Undermountain enemies have 16,000 of all ratings and counter ratings.
If you assume 16,000 counter stats in this scenario, Defense beats HP at ~42,600 stat investment. In Mod 15, the only way I could get around this level of Defense was to purposely invest in a pure defensive build with Azures/Defense boon/as many Defensive slots as possible.
(Or use shepherd's, but given that the devs are aware of many game issues like Recovery devaluing dailies or Lifesteal making players immortal, I would not hesitate to say Shepherd's suffered some form of nerf).
Ok, so I need a ton of investment in Defense for it to be great, sounds reasonable. However, 42600 stat investment is not worth it due to needing to deal with other counter stats. Right now, a tank build can get away with 10,000 or so ArmorPen and then stuffing as much as they can in Defense to max out DR. But considering other counter ratings existing, it's hard to justify using 42600 of your stats just to be only slightly better than HP. For DPS/healer characters, Defense is a non option due to needing a lot of other stats like Power and Crit. Even tanks won't bother with defense, as tanks will need accuracy and a greater deal of ArmorPen to deal "normal" damage to enemies and keep aggro on them.
Speaking of tanks, HP comes out way ahead due to the way Guard was described to work.
Since Guard draws on your total HP pool, the tank will effectively have 2x their HP count under Guard, on the assumption that the tank has perfect play and always shield attacks. I know this may not be the case in reality, but even if you assume the tank shields 0 attacks... you're back to the original problem of the investment of Defense needed being way too high for the effort comparative to HP.
And all of this assumes counter ratings of 16000. I would not hesitate to say harder zones will
have higher counter ratings, which only exasperates the problem even further.
How the devs plan to adjust this problem is beyond me, but I would like to make them aware of it.
I do plan to propose some ideas below to make Defensive stats a little more balanced.