Hearts of Iron III lets you play through the most engaging conflict in world history, World War 2, on all fronts, as any country and through multiple different scenarios. Guide your nation to glory and wage war, conduct diplomacy and build your industry between 1936 and 1948.

Hearts of Iron 3 Developer Diary # 10

Welcome to the 10th chapter of the development diary. This is the final development diary before the holidays, and we’ll be back in the middle of January.
Today, I’d like to talk about the naval aspect of the game, which one of the focus we’ve had in the last few weeks.

When we went off to think about the Naval system we had two real thoughts. Firstly that the ship model system was particularly unsatisfactory solution when you consider the diversity of ships that were designed and built in World War II. Secondly that overall you had two types of naval orders, those you really wanted to get organised and let run and those that you wanted to focus you time on planning.

First off, let’s talk about the model system. We’ve already talked about it a little but I feel it really comes into its own with ships. If you compare the Hood and Scharnhorst, in Hearts of Iron 2 the Scharnhorst is the superior ship in all aspects, as it is a model 3 battle cruiser while the Hood is only a model 2 battle cruiser. However with the Hearts of Iron 3 system we can do a very neat trick. The Hood is a large ship with 15’’ guns and a lot of Anti-Aircraft batteries, however its design is pre-Jutland and thus it had a known vulnerability to plunging fire. The Scharnhorst is much faster, better armoured ship, but only carries 11’’ guns. We can now simulate this; the Hood is defined with much better armament and anti-aircraft values, while the Scharnhorst scores better in engine and armour values. Different ship designs can be different, and naturally these are all modable.

We have also scraped the naval attachment system all together and instead we have defined each individual technology to be upgradeable or not (surprisingly this is also fully modable). For ships it means you can partially upgrade old ships. If you build a ship its main gun armament is fixed for all time, however its anti-aircraft batteries are very much upgradeable. We feel this system sets up the right blend of newer ships being better than older ships without the old ships simply being useless.

Next to Naval orders. We’ve made a couple of changes to naval orders. Firstly we have added the infinite order, for something like convoy escorts, you send you fleet out and the order will run indefinitely. With an added twist, each naval base can also be set up with a pool of reserves. These sit in port, repair if they need it, upgrade if they can, but when ever a fleet that is on an infinite order needs to return to port these ships will be used to replace them (providing they are of the same type). Thus if your ships, have low org, or are damaged, rather than having to go to all the trouble of sending a different fleet out on exactly the same order the system will take care of this automatically. What we’ve tried to do is hold down the planning overhead for your missions, yes you may want to go back from time to time and adjust them, but as long as things are going ok you can leave your naval units to get on with it.

Thus you now have extra time plan your naval big naval operations, like sending out the Bismarck to go convoy raiding in the Atlantic. To help facilitate this we’ve added a cool new feature, multiple detection levels. Knowing an enemy fleet is in a sea zone is not enough to be able to engage it, the ocean is a big place and all you know is that a fleet is somewhere. You need to pinpoint the fleet’s location better than that if you wish to actually fight it. First up we have added a patrol order (best suited for light ships), these ships will search sea zones in its area of operation looking for enemies, if an enemy fleet is partially detected it will focus its search in that sea zone. Once the patrolling ships find an enemy they don’t seek to engage (unless the odds are very good), instead they will try to trail the enemy, keeping it in contact until heavier ships come along to help out. Note the trailed ship has a chance of detecting its shadow and trying to sink it before help can arrive. The final piece of the puzzle is the naval intercept order, this is for your big fleet, and they sit in port waiting for the enemy to be found by your patrol ships. As soon as the enemy is positively identified and they like the odds (which you determine) they will sail off and try and sink them.

I suppose at this point I should mention that the system as detailed above is an optional extra. You can still manually move ships about, set ships onto short timed orders, you do not have to assign reserves. It is up to you to determine how much of the naval war you want to manage.

Johan Andersson, Producer of Hearts of Iron III