[Mass Combat] Cutting supply lines

[Polydamas]

Originally Posted by Michael Thayne

While Mass Combat mentions that land logistics troops require that "a clear supply line can be traced back to home base", it is a little unclear what this means. Movement speeds are mostly given in increments of 5 miles per day, so it's tempting to assume a map with 5 mile hexes and that a single element can render a hex unusable for purposes of tracing supply lines. It also seems like if supply lines can't be cut by enemy units, there's little point in using air logistics troops, unless you're supplying troops that have been paradropped into Mordor or something.

On the other hand, maybe cutting supply lines is meant to be outside the scope of Mass Combat, because it's unclear what the game effects would be. It's not actually true that all military forces everywhere suffer dramatic breakdowns in effectiveness after going a month without resupply—many would, but there are tons of historical exceptions from (the Mongols, ocean going ships in the age of sail, Sherman's march to the sea, etc.) So maybe this is just totally outside the scope of the system.

Thoughts?

Modelling logistics requires detailed maps and lots of arithmetic, so for a little PDF GURPS Mass Combat's rule sounds OK. The details depend a lot on scale (supplying a few hundred troops is different than supplying tens of thousands) and TL (a TL 0 army can manufacture most of what it needs, a rich TL 8 army not).

I would not say that a single element can render a hex unusable, they need to be proportionate in strength to the size of the convoys they will be attacking or blocking. And the difference between rebels holing up in a key pass and building a wall, and mounted raiders rushing out of the tall grass to hit a hard of cattle being driven to your army, gives the players different stories to tell and decisions to make.

If the enemy's troops have Air Logistics, the players can't occupy that strategic pass and hold it until the enemy have to break the siege of the Last Free City (they might make a treaty with the wind wizards to summon terrible storms though ...). If the players' troops have Naval Logistics and they hear about something inland, they have to make hard choices. GURPS Mass Combat is about putting a skin of mechanics around a skeleton of story, given that in a typical group only 1 or 2 people are really interested in playing out technical military stuff for hours on end.