Dev Diary: Supply - A First Look

(Reposted from yesterday due to an error)

Hi everyone and welcome back to regular weekly dev diaries (if you don't count the april fools one last week). I know you are all super excited to hear what we have been up to since Battle for the Bosporus. The answers to that are going to take a few dev diaries to cover, so I figured I would start with a timeline for you:

• We recently released 1.10.4 to fix various multiplayer exploits going on, but seems an important case was not detected at the time so we are working on a 1.10.5 to address that soon.

• Pdxcon is coming up in May so expect to hear some more details there.

• The yearly anniversary is coming in June so expect some cool stuff and a patch.

• We are however spending most of our time on the 1.11 Barbarossa update as well as the unannounced expansion that will be released together with it. That's what we will spend most of our diaries on, as well as today!

‘Barbarossa’ and the unannounced DLC will focus on the Eastern Front and the core of Hearts of Iron, which is warfare - particularly land warfare. Historically the Eastern Front was without doubt the most important front for World War II. It was the largest confrontation in history and is where Hitler’s expansion was first stopped and pushed back signaling the eventual doom of the axis powers. There are several areas we want to improve here. Weather does not feel impactful enough, while historically it had a massive impact. Logistics currently doesn’t have much player interaction and is mostly something you have to deal with only when problems appear, and finally the combat and division meta has been stable (with an emphasis on large divisions) for a long time - something we hope we can shake up. As you can imagine, these are all things that affect the game on a deeper level and take a lot of work to get right.

Today, I’ll give you guys a bit of an overview on the supply aspect, but fair warning: it’s early days and stuff may still change here before we’re done. I’ll probably spend 3+ diaries on supply over the course of the development to cover everything, but I figured it would be nice to hear about the overarching ideas.

The old system worked by having discrete supply areas pathing back to the players capital and keeping track of the bottlenecks. To simplify a bit ;) - those bottlenecks then decided how many units could fit into areas near the front without penalties. The areas themselves were unintuitive to players and required you to check multiple mapmodes to see if you stepped over an edge etc. I do like bottleneck systems though, because feedback is usually immediate, but it suffered from not having much scaling cost as distances increased, so it was hard to use it to limit snowballing. As I mentioned it was also a system you didn't care too much about until you had problems, while historically, logistics was a vital part of planning a campaign. This led to combining the issue with another gripe of ours - that the way fronts moved in WW2 often followed important railroads, but don't really in HOI4. We came to the conclusion that we should try and make a system focused on railways and with a truck based component as a way to get more out of it when away from the rails.

In our new system, supply flows