I didn't see it in the rule book but does Armour degrade after being penetrated?

Or does such trivialities really matter for this game?

No, armour does not degrade when the wearer suffers damage. Also consider that, barring some Critical Damage, damage penetrating armour doesn't necessarily mean that they armour was penetrated/structurally damaged. Instead, kinetic or thermal transfer through the material could explain the few points of wounds suffered from initial hits (this also explains why damage type generally matters very little until Critical Damage is done).

OW corerules p.169, Corrosive - weapons that have Corrosive weapon special quality lower Armour Points on hit location by d10. This degradation can be applied multiple times and if AP drops down to 0 any excess damage is applied to the Target character. This excess damage is not reduced by Toughness.

Character who has Armour Monger talent can repair this damaged armour using this talent.

Only way I have found that makes your armour go POOOF. Not even Melta that uses intense heat do it, but most of the time Melta weapons Pen make jokes about infantry wearable armour.

Thanks guys, I was curious. It came up in converstion at my gaming table and it just seemed a little odd that armor worn by an individual or armoured vehicle would not show the wear and tear of the battler field.

If you want armor to degrade, by all means, make it degrade.

I would recommend using the rules for "Damaging cover" on page 253. Of course, you might want it to degrade faster if something that can penetrate it entirely hits the armor. (Although in this case, the wearer will probably be in bad shape…)

Yeah, i think they left it out because:

1. The game is deadly enough as it is
2. it slows the game down for beginners

so if you wanna put it in then go for it!

If you are considering degrading armor, you probably want to increase the base armor rating.

I wouldn't increase the base armor rating, but to slow down the process in a similar fashion, I'd only reduce armor values for anything above a set amount of damage per hit... small amounts of damage are expected even if it stops an attack. If you wore a L4 vest and I plugged you in the chest with something from a rifle, I assure you that you'd end up bruised and not very happy about the experience until you realize that bruised > dead.

Off the top of my head, I'd reduce armor on hits that either do 4 or 5+ damage or where the pen value negates the effectiveness of the armor altogether.