Note that the winning French need five depots and the losing Prussians only two. The red road is the main supply route for both armies.
You cannot really have a campaign without a campaign supply system. However most of us are more interested in playing with our model soldiers on the table than spending hours working on complicated supply and movement rules.
I wanted supply to play a major role in the campaign, particularly when it was a PBEM campaign. But I also wanted the administration of each daily move to be simple and fast. Having considered the problem I decided that I wanted the supply system to effect the campaign in four ways.
First each corps would only be able to carry limited supplies, and I settled on four days.
Second to resupply they would have to be within one day’s march of a supply depot, and to establish a depot they would have to detach one full strength infantry brigade.
Third each depot would collect one day’s supplies from the surrounding area, providing that they were not under attack.
Fourth if they ran out of supplies they would suffer attrition casualties and would not be able to initiate a battle.
The result of these four simple rules is that the winning army would have to detach brigades to garrison his depot supply chain as he advanced. This would reduce his battle effectiveness just as heavier casualties would affect his opponent.
With a maximum of four days supplies he would have to plan carefully to advance to contact and fight a battle before he ran out of supply. Normally at the end of a battle he would be out of supply, and might well be unable to resupply because he was more than one days march from his nearest depot.
However if he captured a town which was an enemy depot with supplies, he would immediately increase his own supplies. This gave an added bonus to wining such a battle.
As the campaign progressed I amended the original supply rules to allow movement of supplies between depots. CinC (not corps commander) were allowed to move up to four days supplies each day.
Each army would always have 20 days’ supply. If there were not sufficient between what was carried by each corps and held in each depot, the balance would be delivered to the main supply depot each day. The main supply depot is always a town on their edge of the campaign map. So as they advance it gets further behind them.
That concludes the campaign rules. Next time I will explain transfer from the campaign to the table and back again.
You will find my campaign rules here