Slitherine

SUPPLY_PENALTY_DISTANCE 20

What does this mean exactly?

Is this like if I am draw a 3 supply from trobruk and I am 21 hexes away it is now a 2 supply?
Or is it # of hexes from capital reguardnless of terrain.

20 hexes from Berlin 4 supply
40 hexes from Berlin 3 supply
60 hexes from Berlin 2 supply

Also I assume when drawing supply from trobruk it is 3 level and the allies have no way to stop that.

Distance to your nearest Major ACTIVE Capital, so if USSR loses Moscow they will calculate for Perm. The penalty only applies to units that are supposed to have full supply.

So, when Axis is invading USSR you have supply 5 at Polish border, supply 4 near Moscow and supply 3 if being past Moscow all the way to east map edge.