The rules were written to cover the PBEM campaign. I wanted them to be easy to understand and administer. But I also wanted players to suffer a penalty if they did not keep an eye on supplies and include them in their campaign plan.
The rules allow each corps to move for three days without penalty, but if they want to resupply they have to halt on the fourth day. If they fail to do so they lose 400 casualties (one tenth of a brigade) each day until they do so.
To resupply they must be within one day’s march of a depot which has supplies.
Each army can have as many depots as they wish. But they can only be established in a named town, and it takes one infantry brigade one day to become operational. Each depot will then provide one days supplies each day.
So a four corps army needs four depots to maintain full supplies. This means that they must detach four infantry brigades to man the depots.
Even with such a simple method of supply quite a few players failed to do so. Usually they would just fail to establish depots as they advanced, and would only realise it when they actually ran out of supplies. At this stage more than one player quit the campaign.
Now that it is a solo campaign I have decided to change the supply rules. I no longer have to make them “player proof”, because I control both armies.
Each army now has four extra infantry brigades, who form a reserve corps. They form the garrisons of the depots as they are established. This keeps the field army up to full strength, except for battle casualties.
Each army now has a maximum of 20 days supplies that is four per corps and an extra four in reserve held in the depots. If there are insufficient depots to maintain the 20 days, any shortfall is delivered to the main depot each day. So each army always starts the day with 20 days supplies. However they are rarely in the right place at the right time.
When a town is taken the victor captures any supplies in the depot. This is a big advantage, as they are right where they are needed. However he then has to detach one of his brigades to take control of the depot, at least until one of the four reserve brigades can be brought up to replace them.
Depot garrisons cannot take part in the battle, but they will fight to defend the town. However most battles take place in front of, rather than in, the town. So this is only a limited advantage.
The main effect of this change is that armies will never run out of supplies, but corps might well do so. If an army lose one or more depots they will have to retreat towards their main depot in order to resupply. Battles are often fought for towns, which are also often depots. So the loss of even a small battle can have considerable consequences for the whole army.
I have used this new system for five or six campaign moves, and it seems to be working well. It is particularly good in Spain, where the allied armies have four guerrilla/militia brigades to ambush supply columns or attack depot garrisons.
You can find the campaign rules here