I'll be following, and hopefully will learn something.
Welcome, Idhrendur! I hope you will learn something too. Thanks for following along!
I've heard that Rensslaner AARs were great, so I suppose this is a good opportunity to find out myself!
Also, I would support details on battles and OOB, but the choice is entirely yours and regardless I'll see if I can keep up with this.
Welcome, Macke11! I'm glad you've heard that - I hope to live up to expectations! I'll see what I can do about details. The goal is to explain the interesting details while avoiding a commitment to needless turgid details that get in the way of a good story. I'll be trying to strike that balance.
Subbed! Although I think, Uriah's Doppelgänger-AAR is a real landmark for Germany-AARs, but a real different approach will be interesting, too.
Welcome, Racebear75! I've read parts of Doppelganger, but haven't finished it. It's been a long time, though, so I don't remember and probably need to just start over.

Thanks!
Personally, I find that regardless of how much someone has on their plate, everyone needs a hobby.
Definitely following this, it's been too long since a good HPP AAR graced these forums. I'm curious about the infantry bug you mentioned, is that really a bug? I was under the impression that combined arms could be granted to infantry divisions in TFH as the combined arms bonus was completely overhauled for that expansion.
Welcome, Nuclearslurpee! Yes, and I should probably have writing my second novel as my hobby instead of playing games and writing AARs, but this is just in my blood, you know?! Besides, writing fiction is how I got into my first AAR, so it goes hand in hand.
You may be right about TFH and the combined arms issue -- someone else had mentioned it as a bug in the HPP forum and I'd assumed it was. I never really felt it unbalanced anything terribly -- you still don't make great progress anywhere without tanks. I'm just not used to seeing infantry units with combined arms, as my experience with TFH is pretty slim.
Will be interested to see how things go, also any observations along the way as to how HPP was different/better than plain TFH (I'm 'saving up' the two major mods until I have played more HOI3, having only returned to it after a short stint after it first came out). Good luck with the AAR.
Welcome, Bullfilter! In actuality I started with vanilla TFH (I'd played with the HPP mod before, but wanted to both try out TFH and didn't want to bother with modding uploads, etc.). After getting a couple years in, I started obsessing more about growing irritations, like "Darn it, I can't use cavalry and/or garrison units to cover my conquered lands unless I keep up on garrison/militia/cavalry techs, which are a total waste of time and tech research slots." HPP fixes that, so I switched and started over. There's alot more too -- I'm going to borrow/steal and modify an entry from my Kriegsgefahr AAR where I explained the major differences between HPP and vanilla HOI 3...
HPP: The Historical Probability Project Mod
Some of the obvious differences with HPP are superficial. The German battle flag is used, instead of the old Imperial black-white-red. Germany is known as the German Reich. Japan also uses the Rising Sun flag instead.
Ignore that silly picture of Hitler as Head of State – I have some Junker aristocrat as my Head of State. We keep Hitler in a monkey cage and ask him to make public statements from time to time.
One of the key divergences of HPP from vanilla HOI 3 is they have separated out some of the factors which in vanilla are agglomerated and abstracted into an “economic mobilization” status. One thing they’ve separated out is Taxation – how much money your government has available is related primarily to your taxation level, not to your mobilization level. I like this.
Laws in HPP are also more expensive to change, and the larger the change from the status quo, the larger the expense (as opposed to them all being the same cost in SF/TFH). HPP also has generally higher costs for changing any laws.
Industrial Policy Laws have changed somewhat, too. In the Strategy Guide for standard HOI 3 (page 13), I indicated Consumer Product Orientation was only useful during peacetime, and even then Mixed Industry was probably preferable. During war, I said Mixed Industry would do fine, but Heavy Industry was preferable. The choices were essentially “no-brainers” (if collective wisdom on this has changed for vanilla HOI 3 I’d be curious to hear why). In HPP, the consequences of each have changed, and there are no longer obvious choices.
(Note of contrast between Kriegsgefahr (SF) and Early to War (TFH) -- the graphic is 95% the same between SF and TFH, but TFH has added an impact to Resource production levels)
In HPP they’ve added a consequence (greater Supply Consumption) for Heavy Industry emphasis. But the benefits during wartime are also greater (better Supply Throughput and better IC Efficiency – the two reasons you’d still want to choose this during war). The Mixed Industry has smaller degrees of the same tradeoffs, but without the IC Efficiency benefit, which makes it less useful (someone might still decide to stick with MI during wartime, though). HPP’s Consumer Product Orientation is still not a great choice for wartime economies (not a no-brainer, though – someone might choose to keep the Dissent Change benefits), but has become a likely choice for peacetime economies.
The Education and Training Laws (both sets) are significantly different in HPP, but I have no need to change anything here, and so won’t go into detail. The defaults for both are different from unmodded HOI 3. Germany has a “standing army” rather than a 2-year draft. And Germany has a far lower default for Education than in the unmodded game, which I think is probably realistic (again, balance probably decided the default in HOI 3). HPP makes the impact of more intensive Education Laws less (I think only 20% of the unmodded impact on Leadership) than in the unmodded game. I think this is also realistic – I’ve studied education policy a lot, over the years, and as far as I’m concerned, throwing money at education has a relatively minimal impact on results. In HPP the impact is directed more toward relative qualification of the officer corps, and less toward more effective research.
Another note not in the original Kriegsgefahr note: HPP also impacts Leadership positively over time according to how much IC you have and/or other factors which determine the greatness of your empire. I presume if you were to build Turkey (Bullfilter!) into a great power, HPP would reward you with an additional bonus to Leadership.
The Economic Laws – what is sometimes referred to as Industrial Mobilization – are also quite different. Because of the conceptual changes in HPP, the higher range options do increase available IC, but the lower ranges do not, unlike in unmodded HOI3/SF. Also, these don’t have as much impact on the availability of money (this effect having been mostly shifted into Taxation Laws).
I notice that in HPP I seem to need more relative IC devoted to Reinforcement, I believe because the “Manpower Rotation” during peacetime is higher (soldiers retiring, terms of service expiring, etc.). I think this is more realistic too.
Whereas when I played this scenario (
Kriegsgefahr) in HOI3/SF I reduced my mobilization to Full Civilian Economy, to save on Resource Cost/Use, the Resource Cost/Use is less in HPP for Basic Mobilization (the default for Germany), so I leave it where it is. This avoids what would have been higher Consumer Goods costs, and I get to keep my Reserve units at 60% instead of 75% (just in case). The difference between -10% and -20% Resource Use isn’t going to make an enormous difference in my stockpile sizes. The main thing that depletes Stockpiles is the IC use, which isn’t affected by these lower levels in HPP. ((
HPP also artificially retards extremely high resource stockpiles through a "storage penalty" which assumes you'll eventually have difficulty finding places to store all the stockpile)).
Before I move on, I’ll note that in HOI3/SF Germany starts out at War Economy, with +25% IC benefits. In HPP you start out at Basic Mobilization (in unmodded HOI3 that would have meant -25% IC, but not in HPP). This is more realistic and historical (the unmodded game may have set a higher level for balance purposes). The oft-quoted statistic is that Nazi Germany didn’t fully engage itself in a wartime economic footing until 1942 or 1943, historically. Basic Mobilization is about where Germany would have been, historically in 1936.
The elements in the Tech Tree for HPP aren’t entirely different from unmodded HOI 3. There are some differences in what you can research, yes, including old Techs missing and new ones added. As far as I can tell, there is no Garrison/Militia set of Techs, which is fine with me (conceptually, there has never been a difference between technologies or techniques which benefit the regular army versus militias, etc. – militias just use older equipment).
HPP also has a process for filtering increased infantry techs down to the lesser reserve/garrison/militia units so they grow naturally stronger over time from hand-me-down weapons and/or training.
The main change in HPP is that everything is organized differently. Techs are more definitely queued, one after the other (at least this is what I presume from my brief experience – correct me Slan or TheBromgrev if I’m wrong). And many techs cannot be researched automatically – they are keyed to General Staff policies, which may be very different from one army/navy to the next.
Basically, if I’ve not unlocked (chosen) a certain doctrine – differentiated by overall strategy/tactics concept and/or year of advancement – then I cannot research the techs keyed by that doctrine. Because of this, once I make a choice to follow one doctrine over another, there may be techs permanently locked off to me. This is not really a disadvantage because I’ve chosen not to need those techs – I’m heading in a different conceptual direction anyway.
Note from Early to War: I actually feel like the doctrine process is bugged in HPP 333b -- I never, for instance, got the opportunity to choose an armored or infantry doctrine for 1940, which means I need to go in somehow and trigger these or else forego those techs.
Now, I’ll admit that in unmodded HOI 3 I would sometimes cherry-pick techs here and there, based on what benefit they provided. I believe this was sometimes necessary in unmodded HOI 3. I believe it is NOT necessary in HPP because the combat values affected by each tech have been switched around to be (in my opinion) more logical. I no longer have to research Militia Support Weapons (or whatever) to get my Militia units up to speed – they use the same techs as Infantry. I no longer have to have some obscure tech (one of a set of 5) to increase Artillery Morale – that’s affected by the same tech, hypothetically (i.e. I’m not looking this up), as would provide Organization for Artillery brigades. Again, this makes more sense to me – good job, HPP team!
The upshot of this conceptual change in the Tech Tree is that you must make sensible decisions about command/deployment/operation philosophy when those choices come up. It also means it’s wise to keep an eye on which doctrines your probable opponents are choosing, so you know what kind of techs they’ll be researching.
When the choice comes up for Infantry Doctrine (notice Germany is 4 years ahead of your “average” country in Infantry Doctrines), I choose what Prussian/German armies have always chosen since von Moltke – Infiltration Doctrine. Basically, I want to be mobile and send out scouting skirmishers to make contact with the enemy, allowing the rest of my unit to flank the enemy and surprise them. The Infantry Techs I can research will be affected by this, though I’m not entirely sure how, just yet.
The last major difference I want to point out is that HPP adds a fourth tab to the Doctrine techs (I think this is merely an organizational change, but I may be wrong). You must choose your “Operational Doctrine” in addition to your Infantry, Tank, Air, Naval, etc. This affects (more rigidly, I think, than HOI 3) how you employ your whole military. The UK chooses Grand Battle Plan (which, again, is historical).
On the left, in the above screenshot, you’ll notice a different set of Decisions than unmodded HOI 3. Two options for Anschluss, which is good (either might have been used, historically). The HPP Re-occupation of the Rhineland event requires fewer troops on the border than the unmodded event, and I believe the HPP event is more historical.
When I was writing the Kriegsgefahr AAR I didn't know what the Mobilization or Swedish Metal decisions did. Mobilization is an alternative (again, I believe more realistic) method to get your country ready for war. The Swedish metal takes into account the unavailablity of Swedish metal imports during the months when the Baltic was partly frozen -- I don't completely understand the historicity of this, but I assume this was so.
So there you go! An overview of HPP. I'd be curious how ICE (BlackICE now???), for instance, compares.
Macke11??? Feel free to post a comparison or promotional for it here.
Hoping to make an initial non-teaser AAR post from the beginning months of 1936 soon. Thanks for reading! Any comments are welcome!
Rensslaer