During the Allocate Resources Phase, your Headquarters collects all resources for Territories held by their forces as long as those Territories are not trapped behind enemy lines. If the HQ is taken by an enemy, it is shifted through the current supply lines to the next closest territory. It is even possible to shift an HQ from one planet to another as long as the space lanes are clear.
In most cases, your Resources may be used to build lists to fight along any front. However, sometimes a supply line will be cut off by the enemy. This occurs when no clear line can be drawn between two Territories horizontally or vertically without cutting through an enemy territory. In these cases, the Resources in the cut-off territories may only be used to defend or attack from those territories. They may not receive assistance from the other side of the enemy's lines (with some exceptions).
Any Territory which is adjacent to a region of Space Superiority they control or no one controls is considered to have a Supply Line through that region. In this way, it is actually possible to hold territories behind enemy lines and still funnel resources to Headquarters.
Otherwise, an area which is cut off from the Headquarters may still gather Resources, but they must be collected at a Field HQ. if this Field HQ is ever taken by the enemy, the Resources will be gathered by the enemy in their Allocate Resources phase.
Territories which have any Attack Value on them only produce Recruitment Resources in their stipend as all production has been halted during the combat.
You will be asked to generate random resources many times during the course of the Campaign. Use the chart below for this, rolling 2d6.