DiDay's ICE/Tech tree explained

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Understanding the tech screen was somewhat of a challenge so time was spent trying to figure it out. After doing so, here are the findings in order to help others who may have the same issues. This is all done with version 1.3, using both the DiDay's mod (with the land bridge fixes) and mapmap 1.3 mod.

The screen below is the Escorts section of the tech section in Jan 1940 for Germany. As is shown below, I am researching 5 areas in this area as indicated by the magnifing glass displayed in each of these areas. These areas that are being researched are, Nav Torps, Hd-Fd Radio, Sub Hulls, Sub Sonar, and Sub anti air warning. So far so good.

The numbers in the circles indicate how easy a tech is to research ranging from 1-10, with 1 being the easiest and 10 being the most difficult. The various icon(s) listed in the lower left below the name are the practical and theory areas that will help in researching that particular tech. The icon(s) in the lower middle are the areas that will get a +1 to that icons theory value when the tech is completed.

The year (as indicated in the manual) listed is the year that that tech became avaialable historically. However, and this is important, the year does NOT indicate the CURRENT level that the tech is. It indicates what the next year level the tech will be after the tech is researched. So the current Hd-Fd radio is at level 1940 and will be at the 1943 level once my research is complete. Not that my level is currently at 1943 and will go to 1945 when the tech is fully researched.

In addition all tech level that is listed at lv 1 in the main tech titles is considered to be below the 1918 point. This is because the level listed in the tech titles is what the NEXT level will be, not the current level. The game actually has a level 0 (not shown) for techs which are all considered at a pre-1918 point. So the current depth charge tech is actually at tech level 0 for the Germans. If this is researched to level 1, then the Germans will have that tech at the 1918 level and the tech title will have Depth Charge 2 listed with the year 1936 shown. Confusing yes?

The white lines shown in some of the tech boxes indicate how far along that tech is in completing ALL the tech levels for that tech. So I am almost halfway through all the tech levels for Sub AA armment and have not even started on Depth Charges, so no white line is shown. It is NOT an indicator of how advanced you are in relationship to other nations in the game. The US, for example, could have their sub hull white line further along than Germany’s shown below and that would not change Germany’s white line indicated below.  


The last item of importance is discussed with the screen below. As is shown below the next level of Sub AA armament will gain a +9% on air defense. Not bad right? Unfortunately very untrue. The numbers listed in all the techs indicate what the new TOTAL will be, NOT the incremental gain of each tech level. Each level of this tech will gain me a +1.5 increase in this value, not a +9 as indicated here. So, the new level will be lv 6 and the new gain will be 9, so the gain per level is 9/6 = 1.5.

The above is true throughout the entire tech tree. So when you see a gain of 15% in Education, do not get excited as all that means is that when lv 3 research is done, you will have a TOTAL gain over level 0 of 15% (each level is a 5% gain for this particular tech). This will help from researching techs that looked like they were going to have huge benefits. Hopefully this will help from making the mistakes in what to research.


In addition, techs have a 50% penalty for researching ahead. However, once the year changes and the penatily is removed the tech is instantly finished and any leftover research points are rolled over into the next level. Below is an example created by FenrisLokison.

Let's say for maths simplification that a year is 360 days with 30 days a month.

Let's say it's 1936 and you want a 1937 tech.

Let's say your wanted tech would be achieved in 180 days should you begin to search for it in 1937.

So by searching it in 1936, it would take 180*1.5 = 270 days to complete.

So let's say you begin your research the 30/06/36 the game wil check each day if it's finished or not by doing this: day 01/07/36: - days spent: 1 - days to complete: 180*1.5 = 270 => not ok

day 30/12/36: - days spent: 180 - days to complete: 180*1.5 = 270 => not ok

day 01/01/37 - days spent: 181 -days to complete: 180... and that's all because we are now in 1937! => finished!