[The Dark]

Following up from my last post, the biggest issue with having multiple types of armor is that the interaction of Dam and Pen stats gives no real range of plausible AVs, since the same AV2 armor is the minimum to protect against both a .357 Magnum and a 7.62x51mm shot. As such, here's my suggested change in Pen values for firearms:

If Pen WAS Nil, it now IS Nil
If Pen WAS 1-Nil, it now IS 2-Nil
If Pen WAS 2-Nil, it now IS 2-4-Nil
If Pen WAS 2-3-Nil, it now IS 2-4-6
If Pen WAS 2-4-6, it now IS 2-3-4
If Pen WAS 2-3-4, it now IS 2-2-3
If Pen WAS 2-2-3, it now IS 1-2-3

Damage dice may need to be adjusted slightly; I would change the M14 to Dam 5 so that it penetrates AV2 at close/medium and AV1 at long range with its new Pen 2-4-6. Meanwhile, the .357 Magnum can be stopped by AV1.5 and the .44 Magnum by AV2. Suggested AVs would be:
NIJ IIA: 1 (defeats the Dam 2, Pen 2-Nil pistol rounds)
NIJ II: 1.5 (defeats the Dam 3, Pen 2-Nil .357 Magnum)
NIJ IIIA: 2 (defeats the Dam 4, Pen 2-Nil .44 Magnum)
NIJ III: 2.5 (defeats the Dam 5, Pen 2-4-6 7.62x51mm)

Also, blunt trauma is suffered at a rate of 1 point per AV of damage prevented (minimum 1), rather than 1 for 1, so someone shot with a Dam 2, Pen 2-Nil pistol while wearing IIIA armor (AV2) takes 1 point of trauma damage, rather than 2.

Rounds known for armor penetration would subtract 1 from their Pen (so 2-Nil would become 1-Nil, 1-2-3 would become 1-1-2) and also subtract 1 from all damage dice. The P-90 (Dam 2, Pen 1-Nil on Paul's page) would be Dam 2, Pen 2-Nil under this system, but based on the 5.7mm being designed for penetration, it's modified to Dam 2-2, Pen 1-Nil.

This will still need some ironing out, I'm sure. The M16 is a clear problem, since it becomes Dam 3, Pen 2-Nil under this system, which is far too weak. Considering it AP lets it defeat NIJ III armor, which I'm not happy about, but the other solution is likely to up it to Dam 5, since it should be able to defeat NIJ IIIA. Maybe the trauma plates should add a full AV and NIJ III should be AV 3?