Modding difficulty levels

Open the file /db/difficuly.csv and change the values which you want.

The first line VERYEASY;EASY;NORMAL;HARD;VERYHARD is just a comment, so no point in changing that. The next 2 sections are the ones that matter, subsequent sections are not used. The numbers are percentage penalties/bonuses for each setting

I find that the difference between the difficulty levels is too big so I create 2 new levels
1) half way between Normal and Hard
2) half way between Hard and VeryHard
and delete the 2 easy levels which I never want.

Since VERYEASY;EASY;NORMAL;HARD;VERYHARD will always be the options displayed when creating a new game, you have to remember which option corresponds to which difficulty level.

I do not have the original settings any more as I use StonyRoad which I think modified the settings, so for StonyRoad I use the following

HUMAN;;;;;;;X
INDUSTRY;0;-7;-15;-23;-30;;X
RESOURCES;0;-15;-30;-45;-60;;X
MANPOWER;0;-10;-20;-30;-40;;X
RESEARCH;0;-5;-10;-15;-20;;X
ORGANISATION;0;-5;-10;-15;-20;;X COMBAT;0;-5;-10;-15;-20;;X
MOVE_SPEED;0;-3;-5;-7;-10;;X
DISSENT;0;-15;-30;-45;-60;;X
DIPLOMACY;0;-10;-20;-30;-40;;X
INTELLIGENCE;0;-3;-5;-7;-10;;X

AI;;;;;;;X
INDUSTRY;0;7;15;23;30;;X
RESOURCES;0;15;30;45;60;;X
MANPOWER;0;10;20;30;40;;X
RESEARCH;0;5;10;15;20;;X
ORGANISATION;0;10;20;30;40;;X
COMBAT;10;7;5;2;0;;X
MOVE_SPEED;0;2;5;7;10;;X
DISSENT;0;5;10;15;20;;X
DIPLOMACY;0;5;10;15;20;;X
INTELLIGENCE;0;5;10;15;20;;X

The following table shows the option to choose for the new difficulty settings

 Select gets a standard difficulty of Very Easy Normal Easy Normal-Hard Normal Hard Hard Hard-VeryHard Very Hard Very Hard