Why always damage to my forces?

[Cobolt]

Why is there always damage to my attacking forces even when I´m selecting an opponent with no defence?

I mean if a couple of thousand heavily armed guys attack 6 naked guys wearing nothing but mascara and their hairspray, ok, somebody in my army may broke a leg or so because of pure stupidity, but the rest should hav a pretty nice walk in the park eating ice cream and so on because of the total lack of resistance, so why do I pay 500k+ in repairs every time???

seems like every unit takes a minimum damage of 3?

Or am I maby doing something wrong?

I routinley send of a couple of hundred spyes to verify the defences before I attack, than I declare war and attacks.

[The Xeno]

The defense always gets 3 damage. Even if they have no weps.
I usualy think of it as simply my troops using ammo, getting sick from forgien disseases, or any other other mishaps that might occur while off world.

[Guest]

Thank you for your answer! =)

[Wolf359]

Even if the players defence is zero, there will be some costs to your atatcking forces - consider it as the cost of fuelling, maintenance and repair.

[Cobolt]

Thanx for all your answers!

Follow up question:

Is it than possible to have an army that´s big enough to in 1 turn "clean out" one of those many dead accounts that has no defence but 45-50mil and still make a profit?

I´m trying to find out the optimum attackforce and an optimum spending of attackturns for farming among "dead accounts" (those that doesnt upset anyone.)