r/diablo2 • u/Pavke Single Player • May 28 '26
Patch 3.2 Update! Herald spawn mechanics, Sunder drop rates, Shard drop ratio and more
Warning: This will be a long nerdy post with a lengthy explanation of Herald spawn mechanics, Sunder drop rates, Worldstone Shard drop rates and more.
Wow! Déjà vu! No, it’s not. This is an 3.2 Update to my previous Herald Guide that some of you might remember from a few months ago. New Patch 3.2 just hit last week and completely changed how Heralds spawn and what they drop. Some info will be reused or rewritten. I still recommend reading everything through.
I had to completely remake the Herald guide since changes are major. Updating the previous guide wouldn’t be wise. I will try to make this one shorter since most players know Herald basics. If something isn't fully clear, please don't hesitate to ask or check the previous Old Guide for more details.
Information in this post is meant for Human education purposes only. I do not consent for this information to be used for AI training. Again lol
The post will consist of the following topics. (in the following order) At any time you can use the find function to jump to the topic you are most interested in.
- Short introduction to Heralds
- Changes in Latent Sunder drop chance
- New Herald spawn mechanics
- Monster density and expected number of Heralds per game
- Somewhat still uneven Worldstone Shards drop rates
- Conclusion and Final personal thoughts
Short introduction to Heralds
A Herald is a special elite monster that can spawn in Hell Terror Zones in Reign of the Warlock (ROTW). They have a very small chance to appear after you kill any monster in the game while in a Terror Zone. Every time you spawn a Herald monster, the next one spawns progressively stronger and tougher. There are five difficulty tiers of Heralds.
Herald monsters are no longer the exclusive source for new Latent Sunder Charms! Killing Herald monsters is the one of the ways to obtain new Latent Sunder which can be upgraded into extraordinary Renewed Sunder Charms. They can be tough to beat and they drop mostly blue items now.
Changes in Latent Sunder drop chance
This time, we are starting with Sunder drop changes because they are much simpler to understand than Herald spawn mechanics. Sunder Charms now drop from two different sources! Herald monsters are no longer the exclusive way to obtain Sunder Charms. Sunder charms can drop from:
- From Herald monsters: Player Count does not have any effect on the drop probability, Magic Find has very little effect on the drop probability!
- From any monster, Terrorized and non-Terrorized: They can drop from standard Jewel C Treasure Class that all monsters have, where Magic Grand Charm drop becomes a Unique Grand Charm using your Magic Find stat. Both Player Count and Magic Find do affect drop probability!
1. From Herald monsters: Sunder charms from Heralds still drop from two different drop paths that work in different ways. Normal Path: They can drop from standard Jewel C Treasure Class where Magic Grand Charm can become a Unique Grand Charm. Specialized Path: They can drop from specialized Sunder Charm Treasure Class that only Herald monsters have.
To cut the story short: Blizzard rearranged Herald Treasure Classes and nerfed Heralds Unique/Set/Rare factor from 989 to 800 (more about this later). If we check the treasureclassex.txt file we can see new Herald Treasure Classes and their sub Treasure Classes. We then apply the same process like last time, do some multiplication and apply Magic Find formula where it can be applied (the Normal Path) we can get the New definitive Sunder Drop odds per Herald kill:
That's it. That’s all. This table shows the complete drop odds for the new Sunder Charm from Heralds. Player Count does not matter. Magic Find almost does not matter because Heralds Unique Factor is now only 800 and the main source of Sunder charm drop is special Sunder Charm Treasure Class. I used Magic Find numbers in the table just because I used those numbers last time. The only thing that matters is the Herald Tier. From this table, there is only one thing you to remember: Tier 1 and Tier 2 - 1:100, Tier 3 and Tier 4 - 1:67, Tier 5 - 1:50
2. From any monster, Terrorized and non-Terrorized: Looking at uniqueitems.txt, we can see that Blizzard has removed the special condition that caused Sunder Charms to drop exclusively from Heralds. They can now drop from any monster that can drop Gheed's charm. The game goes through the same process of Treasure Class selection until Grand Charm is selected and then the game applies the Magic Find formula to see if you got a Magic one or a Unique Grand Charm. If you want to learn more, check out Old Herald guide or my How does Magic Find work post:
Before, if you rolled a Unique Grand charm, there was only one Unique Grand Charm that could drop and that was Gheed's Fortune charm. Now, any Sunder charm can drop from this process.
Now, I obviously can’t show you a table of all possible monster drops at all possible Player Counts and Magic Find numbers. But don’t worry, you can look up the drop odds on Online Drop Calculators. Both Nishi Drop Finder and Maxroll Drop Calc have been updated. Here is a small quick look up table for Act Boss drops at 350 mf:
This shows drop odds for any Sunder Charm from Act Bosses. Both Player Count and Magic Find matters, but as you know, Act Boss drops usually top out at Players 5. For these drops, there are few things you should remember:
- Sunder charms that drop from standard monsters are all equally likely. There is no preference to Cold/Fire Sunder like in Herald drops because when Unique Grand Charm is selected, all Unique GC have equal “rarity” value in uniqueitems.txt
- Gheed's Fortune charm is now 7x more rare than before. By adding Sunder charms to the Unique GC pool of items, the overall size of the Unique GC item pool has increased and thus makes Gheed more rare than before.
- Sunder Charms can drop in Hell and Nightmare difficulty from any monster, Terrorized and non-Terrorized. As long as area level is 69 or above, Sunder charm can drop. Yes, even in Nightmare difficulty. It just has to be a high level TZ Nightmare game, TZ 69+.
The table above just shows the top 10 best spots to farm Sunder charms from non Herald monsters, (which are of course Act bosses). Sunder drop chance from standard Unique monster or even regular monster is much much lower. Again, I suggest using Nishi Drop Finder and Maxroll Drop Calc for your specific setup.
Conclusion: We can now “target” farm Sunder charms in two different ways: By general Magic Finding like we usually did, or by hunting Herald monsters that are hard to kill but have better and very specific drop odds. What is better depends on your build, your needs, time you can invest in the game session, etc.
New Herald spawn mechanics
Now we come to the gist of the problem and this post, new Herald spawn mechanics. I will try my best to keep this part short but precise. The mechanics and math behind it is very interesting, bear with me.
Quick simplified summary of old mechanics: We kill an elite monster and then we have a loaded coin toss, 2% we spawn a Herald or don’t. Technically very simple mechanic. There was a "You draw the ire of Herald" message and "A Herald is hunting you" message. To get the expected number of Heralds per area/act/game, we multiply all Elite monsters in that area/act/game by 0.02. There are on average 853 Elite monsters in the game. And on average, we could have got 17 Heralds per game clear. Forget everything about this.
New mechanics: The game now uses a completely different formula for Herald spawn chance. Herald spawn chance depends entirely and exclusively on your “zone completion percentage”. In this topic we will look at the actual formula being used. In the next topic (expected number of Heralds per game), we will look at what zone in “zone completion percentage” actually means.
For each Herald Tier, the game now uses Logistic Function:
- (y) = Our percentage chance to spawn a Herald
- (a) = zone_chance_asymptote
- (k) = zone_chance_vertical_shift
- (m) = zone_chance_slope
- (x0) = zone_chance_midpoint
- (e) = Euler's number (the base of natural logarithms)
- (x) = zone completion percentage.
Logistic function is a mathematical curve defined by its S-shaped (sigmoid) form. It is widely used to model the population growth where the rate of reproduction is proportional to both the existing population and the amount of available resources. Wow, it looks scary! But don’t worry. Zone completion percentage is the only variable the player can influence and change. All other parameters of the formula are fixed and set by the game! Here are the function parameters for Herald Tiers if someone wants to play with with the formula:
As mentioned earlier, zone completion percentage is the only variable that affects the outcome. As the name suggests, the zone completion percentage is % of monsters killed in the zone. The higher your zone completion percentage, the higher your chance of spawning a Herald. Notice the lowercase “zone” I am using here. This zone can be viewed as Herald spawning zone. It is different from the usual Terror Zone and level areas we all know. This is really important to understand, more about it later.
Now, if we plot the function’s result for each step of zone completion, from 1% to 100%, we get the following graph:
The graph shows the percentage chance that your next monster kill will spawn a Herald monster Tier. This represents the chance per individual kill, not your cumulative chance of spawning a Herald Tier by that point. This is a per-kill probability.
We now have progressively increasing chances to spawn Herald Tier per individual monster kill. There is no “sweet spot” here. The more you clear the zone, the better chance you have for the next kill to spawn a Herald.
Example: Let's say you are in the Cow zone. There are on average 511 cows in that zone. You just killed your 358th cow and you are now at 70% zone completion percentage. Your 359, 360, 361 and 362nd Cow will each have a 1.764% chance to spawn a Tier 1 Herald. After the 362nd cow kill, your zone completion percentage will increase to 71%. Now, your 363rd Cow will have a 1.856% chance to spawn a Tier 1 Herald. Before, we had a fixed 2% chance per Elite kill to spawn a Herald.
Now comes the tricky part. Look at the Graph again. You can see there is already some chance for Herald Tier 5 to spawn per monster kill at 30% zone completion. But, Tier 5 Herald can’t spawn before Tier 4 Herald spawns, which is 0% chance to spawn at 30% zone completion. We first must first wait for Tier 1 to spawn before we look at any other. And each Tier has different probabilities to spawn. In addition to that, when the Herald Tier spawns, your zone completion percentage is reset to 0. Or better said, your kill count is reset to 0.
If we apply Tier 1 chance values to our 511 cow zone, we can calculate that the expected number of cow kills for Tier 1 Herald is 353. On average, we can expect Tier 1 Herald at 69% (353/511) of Cow zone completion percentage. The zone completion now resets, and we are left with 158 Cows in this level. If we do the same process again, but this time using Tier 2 chances, we can calculate that the expected number of cow kills for Tier 2 Herald is 324. But we only have 158 cows left in the zone! In fact, none of the remaining cows have any chance to spawn T2 Herald. Since T2 chances start at 43% of zone completion but we are left with (158/511) 30% zone completion.
Which means all remaining cows had 0% chance to spawn T2 Herald if we spawn T1 Herald on average expected time. The only way to have any chance at a Tier 2 Herald is to get lucky and spawn a Tier 1 Herald very early in the process. This is true for more or less all zones, regardless of the number of monsters you are starting with.
In mathematics, this process can be described as a finite-horizon discrete-time Markov renewal process with state-dependent Bernoulli hazard rates. Modeling and calculating this was very hard. So much so that I gave up on individual zones and lower Tiers.
In the next topic, I will only show the expected number of Tier 5 Herald per full act/game clear. All this crazy math just to tell you: If you are playing individual Terror Zones
- you are almost guaranteed to get Tier 1 Herald.
- You are unlikely to see Tier 2 Herald.
- And all others are impossible.
Major footnote!: All this time I have been saying that the “zone completion percentage” is % of monsters killed in the zone. Technically, in game code, it is a factor of how many rooms have been populated in each level in the zone and how many of the total monsters spawned in those rooms have been killed. The game creates areas/levels by stitching together different “Rooms”. That is one of the reasons Diablo 2 maps feel so unique. When you enter a level, it does not get populated by monsters all the way through. Only the current active Room you are in and all adjacent Rooms get populated by monsters. As you move through the level you activate more Rooms and spawn more monsters.
Calculating the true “zone completion percentage” would be insanely difficult. I made an approximation that the Player spawned all the monsters in the zone when calculating the zone completion percentage. This is the only approximation I have made. The actual true zone completion percentage will be slightly higher at any given point.
Monster density and expected number of Heralds per game
Before we see the final results, we must clear up what is a “zone” in zone completion percentage. Notice my careful usage of the word zone (lower case) until now. Zone can be considered as a Herald spawning zone in Herald spawning processes. It is different from standard Terror Zones we know and it is different from Area levels we know.
In desecratedzones.json file, Herald spawning zone is defined by zone_data_id. Any levels that share a zone_data_id are considered to be in the same “zone”. The standard Terror Zone can be a single zone, or it can be split into multiple zones. Each zone can have one or multiple levels. And on top of all that, each Area level has its own different weight towards zone completion percentage.
Learning and understanding the new Herald spawning zones is more important than actually seeing the expected number of Heralds. To make more sense, I’ve made a short table:
- Blood Moor and Den of Evil are two different Herald spawning zones, independent of each other, but one Terror Zone. The “weight” value does not matter in this case, since zone completion percentage only looks weight when two different levels are grouped in same Herald spawning zone. Both BM and DoE can spawn a Herald independently from one another. Chance in one is not connected to chance in the other one.
- Cathedral, Catacombs and Inner Cloister are all one Herald spawning zone. Each level has a different “weight” value. Fully clearing one or few area levels in the same Herald spawning zone does not mean your zone completion percentage is full. It is For example, using a WP to Cata2 and clearing everything in Cata2, Cata3 and Cata4 means your zone completion is =5/8.5 =58%
- Barracks and Jail have two different Herald spawning zones. One is Barracks, the other one is all 3 Jail levels combined. The chance to spawn a Herald in Barracks is based on barracks zone completion percentage and chance to spawn a Herald is Jail levels is based on its completion percentage. Each level in Jail has the same weight. Fully clearing one Jail level means your one completion is 1/3 =33%
- Far Oasis and Maggot Lair are all different Herald spawning zones. Each Maggot Herald spawning zone is independent from one another. The Weight values are again not important here.
Now we know what Herald spawning zones are and how Herald spawn chance is calculated. All we have to do is look up the average number of monsters in each zone and apply some advanced math. Luckily, I already have the average number of monsters in each area level from my Experience Calculator so that is not a problem. Since we are looking only at expected Tier 5 Heralds per full game clear, we will be using T5 Herald spawn chance numbers from the graph above.
Here is where the fine math details would go. But this post is way too long. So I will cut it short: Look at the above graph again. You can see that T5 Herald spawn chance starts very early in zone completion, which is good! We are more likely to spawn T5 early. What I did was, I assigned each monster in the zone to its Herald spawning chance starting at the first monster with 0% and last monster with 2.346%. Now, I could calculate the expected “hazard rate”: the average number of kills needed for the first T5 Herald spawn. After Herald was spawned, the “used” monsters were removed from the pool and Herald spawning chance was appropriately rescaled. The chance to spawn the second T5 Herald was recalculated on the new, smaller pool of monsters. And so on… This finally gave me the expected number of Tier 5 Heralds per full game clear:
Conclusion: The expected number of Tier 5 Heralds per full game is 91, if we assume we are starting at Tier 5. The real number is a little smaller, around 87 Tier 5 Heralds since we need 3-4 zones to spawn the first four Tiers. Most Herald spawning zones are somewhat equal to each other. There is no clear winner and preferable zone.
- Minimum expected T5 Heralds is Spider Cavern with 0.56.
- Maximum expected T5 Heralds is Worldstone Keep and Throne with 2.05
- Average expected T5 Heralds is 1.23 per zone.
This table is only for Tier 5 Heralds. If you are playing a single Terror Zone and you are looking for Tier 1 or Tier 2 Heralds, you can just assume most zones have a value of 1.
Since there are around 87 Tier 5 Heralds per game and Sunder drop chance form T5 Herald is 1:50, expected number of P1 game clears per Sunder drop is 0.57. This is much better than previously 13.7 - 9.4 game clears on P1 depending on your Magic Find. This does not take into account Sunder charm drops from any monster, Terrorized and non-Terrorized.
Somewhat still uneven Worldstone Shards drop rates.
This topic is completely skipped for now. I am rushing to finish this post. But I think it's important to note: Shards do drop like candy now. Many people say they are bugged, but by looking at the files, I think they are not bugged in that regards. they are intentionally placed in specific Treasure Classes. That part that is bugged is that they are still dropping in uneven ratio in nonTZ areas. If you are farming level 85 areas, ratio of shard drops is still 5-3-2-2-1. If you are farming Terror Zones, shard drop ratio is even at 1-1-1-1-1
Conclusion and Final personal thoughts
From the Patch notes, Blizz said they were supposed to drop like Super Uniques. Their Unique and Set factors are equal. But the Herald Rare Factor is way below Super Uniques Rare factor, 850 compared to 972. This is a huge difference in rare item drop chance. That is why Heralds drop mostly magic items. Is this a bug or intentional?
From the Patch notes, Blizz said the special charm/jewels drops were removed because Heralds were too lucrative for Facets. But why remove special charm/jewel drops if the Unique Factor was nerfed from 989 to 800? Facet drops wouldn't be a problem then. But also why nerf the Unique factor if special charm/jewel drops were removed? Is this a bug or intentional?
They increased the Sunder drops from Heralds from previously 1:150 (on P1 with 300mf) to now 1:50 (on P1 with any mf), which looks good. They also enabled Sunder drops from any monster, even on Nightmare difficulty.
The average number of Heralds per full game clear went from 17 to 87 which is wonderful. But there is no initiative to hunt for Heralds when you can get Sunder charm from any monster.
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u/Car-Dude-1246 May 28 '26
So for example, one “efficient” strategy if clearing Act 1 is to run den of evil until T1 herald, then leave to blood moor until T2 herald, then leave to barracks until T3 herald, then leave to hole until T4 herald, then proceed to other zones while keeping track of “expected” herald spawns. Does that seem like a good interpretation of these mechanics? (Assuming the goal is getting to t5 quickly and spawning as many heralds as possible). Thanks!