a question about precision

[HJ]

From Doms I manual it would seem that both attack value and precision are a factor in chance to hit a square with missile weapons. Maybe that's why the Abyssians have such a low precision stat (fire gives them increased attack so it breaks even)? Also, the ratio of weapon's maximum range and the actual distance to the target play a role, so it would not be very simple to deduce from averaging out random situations. Other factors include size of the target, how many targets are in the square that is hit, and whether they have shields or not. What is not clear (apart from not having the actual formula written down) is what is the difference between the chance to hit a square, and the chance to hit a unit occupying the square.

While we're at it, where and how does the air shield value factor in would also be good to know.