Howdy, if you are interested in how to use HARP attack tables with Novus 1e or 2e it's pretty simple.
There are Three factors that you'll have to customize: 1) the Novus attack sizes need Damage modifiers instead of Base Damage values, 2) Armor has to be assigned a Damage Modifier instead of an Armor Rating, and 3) the roll results on the HARP attack table.
1) The Novus Attack sizes already align with the HARP attack sizes. So really all you have to do is recalculate the HARP damage modifier into a 2d10 resolution mechanic by dividing it by 5 and do the same with the Damage Cap. So,
Huge +4 / 24
Large +2 /22
Medium +0/20
Small -2/18
Tiny -4/16
2) Armor works basically except that to properly balance with the 2d10 system rather than the d100 system you need to rebalance the base Armors as SL +2, RL +4, CH +6, SC +8, PL +10
3) The HARP attack tables use increments of 10 as tiers of damage. this will get a little wonky in a pure math sense to all we do is reinterpret them as each being 2 increments of +1, starting with +0.
so in Novus that would look like this:
(-4)-(-3)
(-2)-(-1)
+0 - +1
+2 - +3
+4 - +5
+6 - +7
+8 - +9
+10 - +11
+12 - +13
+14 - +15
+16 - +17
+18 - +19
+20 - +21
+22
Overall, this is really easy to implement in game. The one thing that you might want to be careful of is setting the base Defense as 13+modifiers rather than 15+ modifiers for PCs. I tapped this out at work so let me know if I missed anyhting!