IMTU High Guard doesn't exist - LBB2 all the way (well sort of - the weapons and screens have been included on military ships - my holy grail is to find an armour rule for LBB2 ships I'm happy with).
I have been thinking...
Armor is 1Td+1Td per letter, and costs MCr2 per letter.
AV is figured just like drives.
Armor stops hits if it rolls 1d6 for AV or less.
Each hit stopped by armor is an armor letter lost.
Armor replaces line 7 on the Damage table, as well... Allowing it to take additional damage from hits that skipped it.
So, for a modified armored Type T...
Std T.
JD: __ __ F3 E2 D2 C1 B1 A0
MD: H4 G3 F3 E2 D2 C1 B1 A0
PP: H4 G3 F3 E2 D2 C1 B1 A0
C Mod/3: -0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11
Fuel: 160 140 120 100 80 60 40 20 0
Hold: 50 40 30 20 10
T1: 3xL
T2: 3xL
T3: 3xM 12 11 10 _9 _8 _7 _6 _5 _4 _3 _2 _1
T4: 3xM 12 11 10 _9 _8 _7 _6 _5 _4 _3 _2 _1
Revision is:
Armor N6 M6 L5 K5 J4 H4 G3 F3 E2 D2 C1 B1 A0
JD: __ __ F3 E2 D2 C1 B1 A0
MD: H4 G3 F3 E2 D2 C1 B1 A0
PP: H4 G3 F3 E2 D2 C1 B1 A0
C Mod/3: -0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11
Fuel: 160 140 120 100 80 60 40 20 0
Hold: 37 27 17 7
T1: 3xL
T2: 3xL
T3: 3xM 12 11 10 _9 _8 _7 _6 _5 _4 _3 _2 _1
T4: 3xM 12 11 10 _9 _8 _7 _6 _5 _4 _3 _2 _1
The first two hits are guaranteed to hit armor. The next two should, but might not.