Hi All
The FOO rule is totally optional.
It is an attempt to make the arty plotting much more realistic.
It is not realistic for 1 (or no) FOO to be calling in many different impact points...generally one per tube firing...and then micro adjusting them all, every turn, especially when most of them are out of LOS.
The basic idea is that 1 FOO plots 1 shoot (one impact hex). If you wish to hit two spots on the map...you need two FOO etc.
This make the FOO more important, and brings the purchase of them into the planning for your battle.
You laso have to protact them, if they die, you lose their 'shoot'.
It also means you have to be far more careful with the way you use your arty.
There are some other idea in the general FOO rules to do with arty buys and placement of units on the map...which are also an attempt to bring more realism to the game.
I like it. I am also happy to play without it...however, I find games with it tend to be more interesting.
30 different tubes hitting one enemy unit each is easy to make happen...trying to stop an attack when you only have 3 FOO and he has 4 or 5 points of attack...THAT is a challenge
Cheers All