Measure Countermeasure

The pace of armor development and rounds that penetrate said armor is evidenced by the staggering number of new rounds since the Cold War ended.

The Russians improve reactive armor, we improve the APFSDSDU.

We improve the round, the Russians make another improvement to their reactive armor.

Lather.

Rinse.

Repeat.

But such things are, presently, not in the damn rules for GURPS.

So I'm making shit up.  SWAG, but still... 

1st generation Explosive Reactive Armor (Blazer, Kontakt-1) eliminates the armor divisor of HEAT and HEDP and nullifies the special effects of HESH; making them just HE rounds.

3rd generation Explosive Reactive Armor (Kontakt-3), as 1st gen plus: Reduce the armor divisor of AP type rounds from (2) to (1.5).

5th generation Explosive Reactive Armor (Kontakt-5), as 1st gen plus:  Reduce the armor divisor of AP type rounds from (2) to (1.25).  Reduce the armor divisor of the second charge of an MS-HEAT round from (10) to (5).

6th generation Explosive Reactive Armor (Nihz), as 5th gen, except change the AP armor divisor from (2) to (1). 

Spaced armor, as per High Tech p.229, is designated with an S after the DR gives 1.5x the DR vs HEAT and HEDP rounds and negates the special effects of HESH.

Laminated armor is designated with an L after the DR and gives 2x the DR vs HEAT and HEDP rounds and negates the special effects of HESH. 

Starting with the M829A2 APFSDSDU round ignores the effects of 3rd plus generation ERA.  Not sure what to call this ammunition upgrade.  ERA Proofed?  Reinforced Rod?