Armour increase the toughness of ship. Each unit of armour is equivelent to 5% of it's total HP. So a unit with 6 armor is 30% more durable than a similiar unit with 0.

I believe the accuaracy boost allows units to inflict more damage on unit times they normally aren't very good agianst (their is a list of accuarcy ratings in the gameplay.constants file in the gameinfo folder, among other things).

Each full armor point decreases the amount of damage the Hull takes by 5%.  However, my understanding of it is that it's a multiplier, so each successive armor point increase reduces the damage less and less.  The first one reduces it by 5%, then a little less for the next one, and so on.  It's like .95 * .95 * .95, etc.  I could be wrong, but that's my understanding of it.

You're close Centurion. The Armor multiplier, at least the way I understand it, is this.

1/(1+X*.05)

If a unit has two armor, that means the multiplier is .91, or that 91% of the damage that hits the hull (after going through shields and mitigation) will actually hit the hull. That's the way I understood it.

There is a number of entries in the Gameplay.constants file that describe the chance a damage type has hitting a certain target.

For anti-verylight weapons (namely, the weapons flak frigates boast), the chance to hit either type of strikecraft is 75%. Anti-light weapons (the weapons which fighters have) have a 65% chance to hit other fighters, 75% chance to hit bombers.

thanks everybody, that helped sort my head out a lot