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[a_mouse]

Motivation: 

 

For a long time I've been confused about how the Health benefits of Reave work in ME2.  The information that is out there is generally pretty vague and/or conflicting, and scattered about in places that are hard to find.  Based on a recent discussion about it in this thread, I decided to do some reverse-engineering tests to see if I could figure out how it works, and what the relative (health) benefits are of Area Reave vs. Heavy Reave. The results are presented in the following posts.

 

Others have conducted similar tests on Energy Drain, with results summarized in this thread.

[a_mouse]

Background.

 

ME2 Health Tracking and the Heads-up Health Display (HUD).

 

ME2 appears to track player health using a health point (HP) system.  At any given time, the player has a certain number of health points (HP), sometimes referred to as the "health pool." Any damage (D) received below the shield gate is deducted from the current value of HP (if HP reaches zero, the player dies).  Meanwhile health regeneration restores HP over time.  In the absence of any health damage, the player's HP reaches a maximum value (MHP) that varies with class and upgrades (and application of Reave). The current value of MHP is what is posted as "Health" on the player's stat screen.

 

The red health bar in the HUD shows the current HP, expressed as a fraction of the player's maximum health (x = HP/MHP). For example, if the player's MHP is 344, and the red health bar currently reads 50%, the player has 172 remaining HP. In addition to the red health bar, the value of x determines the level of the game's health damage animation (occluded sight and sound, blood vessels, Shep grunting).

 

For some time I was under the mistaken impression that the game tracks changes in x directly by scaling damage to the MHP.  However, one of the tests I conducted below shows that this is not the case.  The game tracks the absolute value of HP, and calculates x by dividing the current HP by the MHP.  (Thanks to capn233 for forcing me to rethink this!)

 

Health Benefits of Reave

 

Upon casting Reave on a debuffed organic target (no armor, shields, or barrier, just a red health bar), three things appear to occur. First, the player's MHP is increased by an amount related to the damage dealt by Reave.  This increase in MHP (which can be seen on the player's stat screen) persists for an extended time period after the duration of Reave ends. Second, the player's current HP is immediately increased by an amount equal to (or greater than) the increase in MHP.  This insures that a player with 100% health retains a full health bar in the HUD upon application of Reave. Finally, if HP < MHP, the player's health immediately begins to regenerate at some prescribed rate for the duration of Reave (3 ~ 5.5 seconds, depending on rank and evolution).

 

The basic questions I tried to address with these tests were:

 

1) How large is the increase in max health? How is the increase in MHP related to the damage dealt to the target(s)? Do multiple castings of Reave increase the MHP more? Does the increase in MHP depend on the number of targets hit using Area Reave? 

 

2) How long does the increase in MHP last after casting Reave?

 

3) How large is the immediate boost in HP?  Is it related to the damage dealt to the target(s)? Do multiple castings of Reave increase HP more? Does the increase in HP depend on the number of targets hit using Area Reave? 

 

4) How does the health regeneration mechanic work?  Is it also tied to the damage dealt to the target(s)? Does the regeneration rate increase when multiple targets are hit with Area Reave? 

[a_mouse]

Effect of Reave on Maximum Health (MHP).
 
One of the first tests I conducted was to cast Reave (of various ranks) on an unprotected enemy to see how much the MHP increases on Shep's stat screen. For a Champion Vanguard (+15% duration) with 5/5 biotic upgrades (+50% damage, +20% duration) on Insanity (duration penalty *0.8), I found that Rank 3 Reave (cast on a debuffed Collector Drone) increases Shep's MHP from 344 to 604 (an increase of 260).  If I understand the damage mutipliers correctly, this value (260) corresponds to the net max damage of Rank 3 Reave (4.0 seconds x 40 HP/second)*(1.5)*(1+0.15+0.20)*(0.8) = 259 HP. 
 
I did not find any relationship between the increase in MHP and the actual damage dealt to the target. Even if the target has a tiny sliver of health left, the increase in MHP is still 260. Also, multiple castings of Rank 3 Reave on the same target (or other targets) does not increase the MHP further beyond 344 + 260 = 604.  Likewise casting Area Reave (which has the same damage and duration of Rank 3 Reave, but a radius of 3m) on a group also increases MHP to 604.  However, casting Reave (of any rank) on on a protected target does not increase the MHP. 
 
I conducted most of these tests on the plaform ambush level of the Disabled Collector Ship (DCS) mission. However, before presenting any examples, I must first report what I believe is a bug in how ME2 calculates passive bonuses. When I load a save game on Normandy prior to the DCS mission, respec to Champion and Area Reave, and then initiate the platform ambush, the observed increase in MHP upon Reaving a debuffed target is 344 -> 604 (a difference of 260). However, if I leave Reave at Rank 3 *until the platform ambush has already started*, and then evolve Rank 3 to Area Reave just prior to arrival of the first platform, the observed jump in MHP upon Reaving a debuffed target is 344 -> 575 (a difference of 231).  Just playing around with the numbers, it seems that the game is not including the Champion bonus: 160*(1.5)*(1+0.20)*(0.8) = 230 HP.  
 
I did not discover this glitch until after filming some of the tests, so the vid below is missing the passive bonus (hence 575 MHP instead of 604 MHP for Area Reave).  However, I saw the same behavior when the game was properly taking the bonus into account.  This video also shows that the MHP increase and damage (to a single target) of Heavy Reave is ~40% higher than Area Reave (as expected based on the 4.0 vs. 5.5 second difference in duration).  Details: Champion Vanguard, 5/5 biotic upgrades, Insanity

 

[a_mouse]

Reave Max Health Bonus Duration

 

I measured this by Reaving a debuffed organic enemy, and then checking the stat screen at various intervals after hitting the target to see when the increased MHP wears off.  It seems to be 30 seconds every time, regardless of rank or evolution of Reave (on Insanity - I did not check other difficulty levels). Here is an example: 

 

 

Two interesting side notes.  First, I arranged it so that I would have partial health at the 30 second mark.  You'll notice that when the 30 second duration expires, the value of the fractional health (x), as displayed in the HUD, jumps from x = 0.4 to x = 0.7 (and the intensity of the damage animation suddenly decreases).  This corresponds to a value of HP = ~240 when the MHP drops from 604 back down to 344:

 

240/604 = 0.4

240/344 = 0.7

 

This proves that ME2 tracks changes in HP (not % health as I originally thought).  It also shows that the red health bar in the HUD can be used to make a crude calculation of HP (provided the MHP is known).

 

Secondly, the jump in the value of x at the 30 second mark provides a measure how long it takes the HUD to register "instantaneous changes" in the ratio of HP/MHP - about 0.5~0.6 seconds. This provides a criterion for separating instantaneous jumps in HP provided by Reave from the health regeneration benefit it provides over longer time periods (3 ~ 5.5 seconds).

[a_mouse]

Direct Health Boost of Reave

 

In addition to temporarily increasing max health (MHP) for 30 seconds, Reave also provides an instantaneous boost in HP. (if didn't then casting Reave when you are at full health would cause %health in the HUD to drop below 100% due to the increased MHP, initiating the damage animation, which makes no sense!).  One might guess that this boost in HP is simply equal to the increase in MHP in order to maintain HP = MHP when Shep has full health.

 

In order to measure this, I exposed Champion Vanguard Shep to fire on the collector platforms, and tracked the health meter before and after casting Reave.  I then multiplied the observed values of x by the current MHP to estimate changes in HP. I then compared Rank 3 Reave and Area Reave, since these evolution are the same damage and duration, but differ in the number of targets hit simultaneously:

 

 

Although these estimates of HP are crude, the increase in HP following hitting a target with Rank 3 Reave is about 250~270, in reasonable agreement with the max health bonus (260). The instantaneous jump in HP for Area Reave when it hits a single target is also ~260.

 

In contrast, casting Area Reave on multiple targets seems to cause an instantaneous increase in HP much greater than this (420 ~ 460). The exact value is difficult to tell because %health basically jumps to 100% within ~0.5 seconds.  However, for the boost to be this large I am guessing the game must be multiplying the total damage (260) times the number of enemies that are hit. This is quite different than the boost in MHP (which does not increase with the number of enemies hit). The tests also seem to show that the state of health of the target does not effect the boost in HP.  As with the increase in MHP, the enemy can have a tiny sliver of health left and you still get the full boost in HP.

 

These observations imply that Area Reave has a significant advantage over Heavy Reave (in terms of health leaching) provided multiple targets are available and within 3m of each other.  The issue is certainty vs. probability.  For a single debuffed target, Heavy always a has 40% greater health boost than Area. But if you happen to have two debuffed targets near each other, Area has a 43% advantage over Heavy (while also doing more damage and immobilizing multiple targets).

[a_mouse]

Health Regeneration

 

As if granting massive bonuses to health and max health were not enough, Reave also provides health regeneration at some prescribed rate for its duration (3 ~ 5.5 seconds, depending on rank and evolution). 

 

Based on the video above I tried to measure this rate in HP/second by examining the footage frame by frame in iMovie. Given the uncertainties in calculating small change in HP from the HUD display, as well as uncertainty about exactly when the health regeneration begins and ends, this was very difficult, and I'd say the numbers I am reporting here are probably ±50%, at best.  But here they are:

 

Rank 3 Reave, single target: ~30 HP/second.

 

Area Reave, two targets: high, but hard to measure since the instantaneous HP boost is so massive there is not much left to regenerate.

 

Area Reave, single target: ~60 HP/second.

 

I am a bit at a loss to explain these numbers. Based on previous tests with heavy Reave, I've observed that when Shep is on very low health, and then Reaves the final mook in the room (while taking no additional damage at the same time), the health boost is about ½ instantaneous and about ½ over time.  This would seem to imply that the integrated health regeneration is equal to the total damage of Reave (just like the boost in MHP and HP are). Thus with 5/5 biotic upgrades, the regeneration rate for Rank 3 Reave (or Area Reave on a single target) should be ~60/second.  Thus the observed value of 60/s for Area Reave on one enemy is about right.  However, the very slow observed values for Rank 3 Reave are hard to explain (should be 60 if this hypothesis were really correct).  

 

However, bonus health regeneration is not really very important when Shep is behind cover (as in this test), since the instantaneous boost in HP recovers most of the health anyway. Rather, the benefit of regeneration is that Shep can remain under sustained fire while maneuvering without drops in % health. This is vary hard to test directly without a lot of information about the rate of damage being received by enemies.  So for the moment, all I can do is speculate that the health regeneration rate probably scales the same way as the HP boost, favoring Heavy on single targets and Area for multiple targets.

[RedCaesar97]

Nice work with the tests. This kind of stuff takes time and effort so I thank you for taking the time and effort to test this out.

 

I will review it again when I get more time. I just had to skim it quickly right now, but I want to take the time later to look at it more closely.

[capn233]

Nice work.

 

The other day when I was looking at the original test, I couldn't figure out why the Champion bonus seemed to be ignored, but that explanation makes sense.

 

Also regarding Area Reave, I thought something funky was going on with multiple targets since it seemed from way back that it was better for survivability, but I wasn't crunching numbers on it and thought maybe it was just reduced volume of fire from multiple cc'd targets.

 

It is interesting to note some of the differences between Reave and Energy Drain (which was tested similarly by Athenau a while ago).  Energy Drain also multiplies its stat damage by targets hit to increase your shields.  The difference being that even Heavy Drain has a radius, so it can potentially hit multiple targets.  The consensus was that Heavy Drain was usually better for shield boost because it was guaranteed 25% more shields, and then potentially even more if you happened to hit 2 targets.  So it also did not depend on the health of an enemy, if they had a few hp and where hit by Heavy you still got your stat amount of shields.

 

For the regen rates, I figured this would be the hardest to test.  I don't know why Rank 3 Reave would behave like that I would have guessed the game always uses the damage rate for your health regen.   Maybe it would be worthwhile to test Rank 1 and Rank 2 Reave and see what their regen rates are to make sure the game doesn't do something unusual like peg the regen to the level of Reave instead of the actual rate (which is the same at all levels except Heavy since ranks give duration).

[a_mouse]

Nice work.
 
It is interesting to note some of the differences between Reave and Energy Drain (which was tested similarly by Athenau a while ago).

Thanks!  Did Athenau post results or vids of these tests somewhere that are still available?  If so, let me know and I will update the original post to cross-reference them.  

[capn233]

Thanks!  Did Athenau post results or vids of these tests somewhere that are still available?  If so, let me know and I will update the original post to cross-reference them.  

 

This was the thread: Energy Drain is Amazing.

 

The interesting thing about Energy Drain is you can buff your shields more than Assault Armor.

[a_mouse]

The interesting thing about Energy Drain is you can buff your shields more than Assault Armor.

Indeed, I am finding double protection Sentinel  based on AA + ED to be monstrous (and considerably more synergistic than AA + Reave, since the their boosts stack in the shield pool rather than contributing separately to the shield and health pools).  

 

I kinda wish Bioware had made ED work on barriers in ME2.  This would have been more consistent from a metaphysical standpoint (given that ED can boost Shep's barrrier if he is a biotic class), and would have made the talent more universally applicable.  They could then have nerfed Reave against barriers and/or armor so that it was a bit less overpowered (forcing a real choice between stripping protection and CC/health leaching).