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From: Oerjan Ohlson <oerjan.ohlson@t...>
Date: Mon, 01 Oct 2001 19:04:36 +0200
Subject: RE: FMA DSII

Brian Bell wrote:

 >Thanks for your critique!

You're welcome :-)

 >One of the things that I have considered is to require both the
 >Power Die and the Impact Die rolls exceed the Armor die roll for
 >a kill.

I haven't had time to look at this fully yet, but it could work.

I wrote:

 >There is another DS-FMA system in testing, based on what Jon posted on
 >this list some years back (Mars 7th, 1999) . It is slower than Brian's
 >system due to using multiplication rather than an immediate comparison
 >the die rolls, but it does a better job of retaining the respective
 >characters of the various weapon families. (Still not an exact match,

Jon has given the OK now, so here goes. I hope the various tables come 
through more-or-less readable... but I don't expect them to <sigh>

Initial notes:

1. This is one possible idea of how the DS3 FMA damage system might
There's no guarantee whatever that the final product will look anything

2. These rules are deliberately designed to use multiplication, because
gives the probability distributions I want (and also because it takes me
considerably less time to multiply two numbers than to add five numbers
together <g>). When it says "the firer rolls an Impact die and
the result with the weapon's size class", it means exactly that. It very
emphatically does NOT mean "roll a number of impact dice equal to the
weapon's Size Class and add the results together."!

3. For the purpose of these rules, "heavy weapons" include all DS2
which have a chance to damage targets with armour/1 or more in DS2 from
front. (In other words, everything but infantry rifles and APSW. The
is still out on HEF artillery rounds though.)

IAVR changes:
IAVRs now roll 1D8 to hit; the target is hit on rolls of 3+.
IAVR warheads count as size class 3 (same as GMS/L).
[See below for why.]

Heavy weapons fire against armoured vehicles:
After scoring a hit by whatever game mechanic is appropriate for the
weapon, the firer rolls an Impact die and multiplies the result with the
weapon's size class while the target rolls 1D8 and multiplies with the
target's armour rating.

If the final Impact score EXCEEDS the final Armour score, the target is
destroyed. [This means that soft-skinned vehicles are always destroyed
hit by a heavy weapon - they multiply their Armour die with 0. This is
reason for the IAVR modifications; without them they'd *automatically*
any soft-skinned targets within range.]

If the final Impact score does NOT exceed the final Armour score BUT the
Impact die rolled its MAXIMUM VALUE (eg. a D6 rolling a "6" or a D10
rolling a "10"), the hit has inflicted Special Damage.
Roll a D8:
1-3: Mobility hit
4-5: Systems Down: Target
6-8: Damage

If the final Impact score does NOT exceed the final Armour score and the
Impact die rolled LESS than its maximum value, the hit inflicts no
significant damage.

Fire against infantry, and infantry fire vs. softskinned vehicles:
When shooting at infantry, you don't have to roll to hit. Just roll the
Impact and Armour dice and multiply by the appropriate factors; if the
final Impact score EXCEEDS the final Armour score the infantry target is
destroyed. Special Damage does not apply to infantry targets.

Armour/0 vehicles count as "PA" when fired at by non-heavy weapons,
that Special Damage results DO count against them.

Note that most heavy weapon types have a fixed Impact multiplier against
infantry, independent of their Size Class (see the tables below). Eg., a
HEL/1 and a HEL/5 both roll 1D4x2 for Impact against infantry.

Heavy weapon Impact die types:

		 Range: 		 All size classes
Weapon	Close	Med	Long	vs. Infantry (1):
- vs ablative	D4	D4	D4	n/a
- vs other	D8	D8	D8	D4x2
HVC		D10	D8	D4	D4x2
RFAC		D10	D6	D4	D4x2
MDC, HKP	D12	D10	D8	D4x2 (2)
DFFG (3)	D12x2	D12	D6	D6x3
HEAT (4)
- vs reactive	D6	D6	D6	n/a
- vs APFC (6)	D4	D4	D4	n/a
- vs other	D10	D10	D10	D4xSize (5)

(1) The Impact multiplier vs. infantry is fixed for most weapons. Eg., a
HEL/1 and a HEL/5 both roll D4x2 against infantry, rather than D4xSize
(2) HKP cannot damage infantry
(3) Yes, a DFFG/5 at close range rolls 1D12 for impact and multiplies by
2x5 = 10. This is *weaker* than it is in the chit system...
(4) "HEAT" includes GMS, IAVR and SLAM. Of course these types may use
types of warheads in the future, but in DS2 they all have the same type
warhead and their ancestors of today have HEAT warheads so I use that
"collective" name for all of them :-7 GMS/H = size class 5, GMS/L and
= size class 3.
(5) SLAM only. GMS and IAVR cannot damage infantry.
(6) IAVR only. This supercedes any reactive armour the target might

(Yes, "Red" chit validity can translate as both D6 and D8.)

Infantry weapon Impact die types:

			 Combat type:
Target is...	Firefight:	Close Assault:
In the open	D10		D12
Soft Cover	D6		D10
Dug In/Urban	D4		D6

Impact multipliers:
Line and Militia:				x2
PA, APSW (and Assault Teams in CA)	x3

Infantry "Armour ratings":
Militia:		3
Line:		4
PA, armour/0:	7 (Yes, seven. No, this is not a typo.)

Artillery impacts:
Ammo:	Vehicle:	Vehicle,		Inf:	Inf., dug-in:
HEF		D4	No effect	D10	D6
MAK		D10	D6		D4	No effect

Artillery Impact multipliers:
Type:		Vehicle: Infantry:
Light		1x	2x
Medium	2x	3x
Heavy		3x	4x

Final notes:

First off, big kudos to Mikko Kurki-Suonio for analysing the DS2 chit
system. That saved me a *lot* of work (as Brian recently found out <g>).

This system attempts to emulate the results of the DS2 chit system. It
by no means an exact match; for example the QDS generally gives a higher
number of kills but a fewer damaged targets (except for size/1 weapons
shooting at very well-protected targets). In addition the "Systems Down:
Firer" results have been eliminated from the damage resolution. It does
however keep the "flavours" of the various weapon families relatively

What I've done is to try to get get the value

P(kill) + P(special damage)/2

for the QDS to be as close as possible to the value

P(kill) + P(both M and SD:T damage) + (P(damage and/or no more than one
SD:T and M))/2

for the chit system, while still having all weapon sizes within a single
family use the same Impact die type in a given range band. (Fortunately
me, RFAC and HVC have different names so can be considered as different
families! <g>) In the infantry case I've just looked at the straight
- infantry doesn't take any special damage, after all. As you can see, I
consider vehicles which can neither shoot nor move to be "destroyed" -
they might be salvagable after the battle, they have been knocked out
the time being...

Playests so far suggest that HELs, HVCs and size class/1 weapons from
other families have gained a little in lethality while most others have
a little, particularly at close range. OTOH, this reduced lethality
compensates for the eliminated risk for SD:F results which plagued the
larger size classes in the chit draw system! Reactive and Ablative
also seem to have gained a little in efficiency.

The "Special Damage" mechanic gives even small weapons a chance to hurt
heavily armoured targets - as a (real-life) designer of light
weapons I feel that that's important! <g> Note that there are NO "BOOM"
"Systems Down: Firer" results - the former is unnecessary since the
"standard" kill mechanism (ie., exceeding the Armour score) gives more
kills than the "standard" chit-draw kill (getting enough valid numerical
chits), and IMO the latter belongs in the to-hit mechanism rather than
the to-damage mechanism.

Some playtesters have asked why the QDS doesn't use the "if Impact and
Armour scores are equal, the target is Damaged" mechanic. The reason is
the probability to inflict such a result varies very "unpredictably"
one weapon class to another one size class of a certain weapon family
have a 25% chance to inflict a Damage result against a certain armour
die/class, the next bigger one 0%, and the next bigger again 10%... not
good thing IMO. A variant of this is "if Impact and Armour DICE (ie.,
multiplication) values are equal, the target is Damaged", but this hurts
small low-impact weapons badly and it makes it completely impossible to
a "Damage" result if the weapon's Size Class is bigger than the Armour
Rating (even if the weapon is low-impact).



"Life is like a sewer.
  What you get out of it, depends on what you put into it."

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