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 Post subject: [MT] Ishmael's stuff
PostPosted: Fri Jul 04, 2008 3:01 pm 
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I figured that I'd start a thread for various bits and houserules I want to share, but I don't want to muck up the boards by scattering them all over the place, so I'll put all my own stuff here. People will know where to find them at a simple glance.
( or know where to avoid :D )

I'll eventually touch on pretty much everything possible.
Just trying to keep the place neat and tidy.

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PostPosted: Fri Jul 04, 2008 3:02 pm 
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COMBAT SYSTEM v 0.1
damage results

This is an attempt to make a combat mechanic that is easy and quick in
play based on the MegaTraveller task system while giving reasonably realistic
results. I hope to include both penetration and damage from MT weapon stats yet
keeping the quickness of the Azhanti High Lightning mechanic.
Another desired result is the ability to use a simple model for unimportant
npc's while having a better, more detailed model for players while keeping
reduction in abilities from wounding similar.
In order to attain the quickness of AHL, I will be basing this mechanic
partly on the AHL damage table. Ordinarily, on a hit, penetration is added and
armor is subtracted from 2d6 and indexed into a chart of possible outcomes.
However, in order to satisfy my requirement that the better one rolls,
the better the damage will by, I instead replace the 2d6 with the amount that
the hit roll was beaten and a single d6. With this, better rolls equal better
results in inflicting combat damage onto the enemy and still have a measure of
randomness. The 1d6 is needed because in MT, the 'hit' roll would have to be
beaten by an average of '7' otherwise to get similar results as in AHL.
This 1d6 could also be used as a hit location die for instances of
partial armor, or for called aimed shots..aka, 'sniping'. By making a called
shot, the task increases a step in difficulty, but if successful, the player may
place the 1d6 to any value or hit location that he wishes.

Code:
1d6          hit location
6         head
5         chest
4         abdomen
3         leg
2         arm
1         scratch


1d6+dice roll-task number+penetration-armor
Code:
less than 4      no effect
4 thru 7              minor wound
8 thru 11              major wound
12 or more              death


As this gives similar results to AHL, I wished to include MT's damage
information into the mix. I feel that the interplay between penetration and
damage is what gives weapons their uniqueness. It is a guess on mine that
somehow, the number on AHL's chart might correspond with a damage multiplier.
The amount of damage caused is the product of the damage chart number times the
weapon's damage number.

In order to figure this out, I had to first find the manner in which AHL
is converted to CT combat. This information is available in Striker which uses
the same basic system as AHL. I then figured the correlation between the AHL's
'minor/major' damage and dice damage. In Striker, minor damage is 3d6 and major
damage is 6d6 in Classic Traveller terms.


The following chart can be constructed.
Code:
                     (damagemultiplier)
                        
1         no effect            .5
2         no effect            1
3         no effect            1.5
4         minor               2
5         minor               2.5
6         minor         3d6      3
7         minor               3.5
8         major               4
9         major               4.5
10         major               5
11         major               5.5
12         death         6d6      6


In this case, I purposefully placed the 6d6 at 'death' for the following
reason. It allows for a simple linear relationship between the dice damage and
the damage chart number. The damage chart number divided by 2 becomes dice
damage. I figured that 6d6 could very well be a 'death' outcome as that is the
same number of dice used in character generation to determine a PC's stats.
While I am no statistician, it appears to me that this results gives a slightly
better than 50% of causing an average PC's death.
Another nice coincidence is that this damage chart number divided by 2
can also be 'damage' used with life points in regular MT combat.

This brings me closer to my goal.

Naturally, having every weapon rated with a single damage value is
simplistic and workable, but 'bland'. Different weapons have different
characteristics and it'd be good to be able to show this in the game.
With Fire,Fusion and Steel, players can design their own weapons.
Although it uses a completely different method for combat ( TNE ), weapons are
built using real terms such as muzzle velocity. The supplement Guns,Guns,Guns
uses the same terms in addition to giving more detail in some areas. In GGG,
ammunition is 'built' and bullet mass is considered, which FFS lumps in with
total ammunition mass ( bullet, shell and casing ).
This is an important distinction as I will be using bullet momentum for
damage instead of muzzle energy. A series of comments in a thread on COTI
concerning old west weapons and the differences between large caliber, 'heavy'
bullets at lower velocity compared to small caliber bullets at high velocity.
Given that penetration is related to muzzle energy per unit area, for a
given muzzle energy, a smaller caliber would always rated better. I felt that
this did not show the heavy calibers correctly.



Starting with muzzle energy, I needed to find a simple way to find the
bullet's momentum.

me=.5*m*v^2
v= sqrt(me/2m)

this can be substituted into the equation for momentum.
momentum=m*v

substituting sqrt(me/2m) into 'v', we get
momentum = sqrt(2*m*me)

What needed to be done was to figure the proper ratios to use to make
it fit the modified AHL damage table and dice.
Picking a weapon that I had official details for, the tech13 7mm ACR
from FFS ( me=4800, m=.008kg) and compared it to a similar weapon from MT. With
a pen=3 and dam=3 in MT, I set it alongside the 3d6 on the table and using
information about me and ( from GGG) bullet mass ( density of lead ), I set the
following where momentum is proportional to the number of dice damage. Using
values for me and bullet mass from the example rifle, solving for 'X' will give
me the equation for damage which when multiplied by the damage multiplier in my
table, will give me total dice damage to the target.
me is in joules
m is in kg
1 = X * sqrt(momentum)
1 = X * (2*me*m)^.25
X= 1/3

dam=((2*me*m)^.25)/3

Now we have everything we need to convert guns, or any kinetic based
attack/accident into MT terms.
Here is my conversion data from a long time ago

Weapon stats;
penetration=((Me/(b^2*.7854))^.25)/4 round down
damage= ((Me*mass *2)^.25)/3 round to nearest
1/10 *
( for use with my AHL damage table variant)
attenuation=sqrt(50*bullet_mass/b^2)/2+1.25 round to nearest
bullet_vol=b^3*(.785*(Q-1)-.262)/1000 cm^3
bullet_mass=sg*bullet_vol grams
muzzle_velocity=sqrt(Me*21630/bullet_mass)/3.28 m/s

Me=muzzle energy in joules
b=weapon bore in millimeters
Q= length/width ratio of bullet ( 1=sphere,2=pistol bullet,3=rifle
bullet..etc..10=sabot penetrator )
if sabot penetrator is used with l/w=10, then b= diameter of
penetrator...not of barrel
sg= specific gravity of bullet material
take this info from armor material lists in tonnes/m^3

melee blade weapons figure pen using a contact area of 1 cm^2 ( no reason except
it gives number that are close to what guns,guns,guns gives ) for swinging attacks
perhaps a quarter of this for stabbing attacks?...weapon x-section for blunt attacks
I'll work it out better in a future post

*With smaller weapons, often the differences are small, so I keep one decimal
place. With small numbers, its often easy to multiply quickly with the single
digit numbers often taken from the chart and with big numbers, it can probably
be ignored.


This is the basis for my kinetic energy damage. It can be very detailed
and yet offers 3 steps of increasing simplicity.
1 AHL style 'minor/major/death' damage
2 MT style points damage with a lifepoints
3 Simple straight dice damage
4 Detailed damage that takes bullets caliber and mass into
consideration.


One good thing about this system is that it could conceivably be used to
figure ANY damage from kinetic impact...melee weapons or falls from height, or
hit by vehicles, etc. All thats needed is information about energy, mass and
momentum and common sense with DM on the damage table.
For melee weapons ( which would be 'built' using a design sequence like
FFS yet simpler ). The essentials are mass, length and type. ( to be detailed in
another paper )
Energy would come from combatant's strength and time spent
swinging/putting energy into the attack. This time could be in seconds or AP's
or whatever logical time step you wish. I base swing energy of T. McInnis' <sp>
way of figuring 'powerplant' power for rowers in boats. In that system, a
normal human can output 63 watts ( IIRC), so in order to make the math easy, I
assume 70 and at str=7, this gives a reasonable ratio of 10 watts per str or 10j
per sec per str point. By using joules/sec, I can figure joules energy in a
swing for 1 second of swinging. If I set an AP in my combat variant to be 1 sec,
then figuring melee attack energy is simple. Joules energy and weapon's area at
impact ( spear tip, axe blade, club, etc. ), we can know penetration. With mass
and energy known, momentum for damage can be found. We can then use these as
dm's for the modified AHL table.
Falling damage can be found by finding the body momentum at impact.
Assume no penetration. For the 1d6, use it if the body falls out of control, or
'0' if jumping down from a height ( controlled landing ).
To find momentum, first find potential energy of body. This should be the energy
with which the victim impacts.
PE=m*g*h. m=body's mass
g=local g's in m/sec^2
h=distance of fall

substitute into the equation.
dam= ((2*g*h*m^2)^.25)/3 this assumes a straight drop without
horizontal velocity added

This actually give slightly more damage than MT's rule concerning 8d6
anytime someone falls more than 9m automatically. However, if jumping down in a
controlled fashion, the amount that you beat the success roll becomes a
dm...negative in this case for AVOIDING damage. Conversely, a failed roll then
becomes the +dm causing more damage. Armor continues to count as a -dm.
The same idea applies to damage from being hit be a bus or other
vehicle. Figure energy, possible penetration and momentum, Use that information
to find base damage to be multiplied by the table's damage multiplier.



So what happens if dm's cause the damage table number to be less than zero?

Its possible that 1d6+dice rolled-success#+penetration-armor comes to
less than zero, and yet the base damage number is high enough to warrant damage
being taken even when the armor is not penetrated. An example of this might be a
tech-7 100mm recoilless rifle hitting battledress with a HE round ( based on MT
numbers for this )...or making a successful roll upon jumping off a 2nd story
balcony to the ground. The table needs to be extended into negative numbers.
On this table, 1 represents a damage multiplier of .5, but we need to go
lower. A model that should work is from MT's danger space damage... half the
damage for every step below 1. The table then looks as follows. Now its possible
to be shot while wearing body armor, have no penetration, yet get a whopping big
bruise at the point of impact.

Code:
1d6+dm's_________AHL______________CT_______________multiplier____
...                           ...
-6                           1/128
-4                           1/64
-3                           1/32
-2                           1/16
-1                           1/8
0                           1/4
1         no effect               .5
2         no effect               1
3         no effect               1.5
4         minor                  2
5         minor                  2.5
6         minor         3d6         3
7         minor                  3.5
8         major                  4
9         major                  4.5
10         major                  5
11         major                  5.5
12         death         6d6         6
13                           6.5
14                           7   
...         ...         ...         ...


1d6+#rolled-success#-armor+pen
(#rolled-success# gives a positive dm equal to amount the success roll
was beaten by)
for CAUSING damage, if failed, you don't enter the table; the amount the
success roll was missed gives an indication of how far the shot missed

If the roll was to AVOID damage ( falling or jumping down where player can be
hurt even on a success, but less than if failed ), then add the amount the roll
was MISSED by for damage caused by failure and subtract the amount the roll for
success was beaten by.

failure causes more damage and success causes less damage.

Knockback
Because we know how much momentum the bullet,etc, has, when we know how
much the target masses, we can figure knockback easily. While the values will
end up being greater than experience suggests, knockback won't have much affect
on soft targets like squishy humans. Against hard targets is another matter.
Humans in battledress or other hard armors can be knocked down by an attack, and
they will be knocked down if the attack's momentum is large enough ( say, as in
being hit by a bus, wrecking ball or a 12-pounder in the chest....maybe even
with a sledge hammer.) I'll have to investigate this a bit to find out how much
is necessary to cause a human to fall down or stumble even.


okay...I need to learn how to make pretty charts/tables
can someone tell me how please?
I'm getting closer at least

I think the equation in guns,guns,guns is bad
if pen is proportional to energy per area, how come its dv calc does not seem to reflect that?
maybe I'm missing something
I changed it a bit to calc MT's pen

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Last edited by Ishmael on Sat Jul 05, 2008 12:55 pm, edited 1 time in total.

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PostPosted: Sat Jul 05, 2008 2:11 am 
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I've checked out damage and penetration for melee weapons using my ideas
concerning momentum. I think not too many people will like it much. It follows
guns,guns,guns fairly closely and shows that the pen and dam values given in MT
are wrong ( probably to make them more exciting so people would actually use
them ).

Assuming 10*str joules and testing values for various swings ( jabs using 1
sec, to roundhouse taking 5 sec ), the average guy will have a pen of 1 and a
dam of 1 using my AHL variant ( MT dam=3 ).
This is similar to pen and dam as figured for a handgun such as a .45 colt.
This corresponds with values for similar weapons in guns,guns,guns, thus I'll
accept them. Once I write up my combat system, they'll seem deadlier as you'll
be able to trade endurance for strength; you can give it all you've got, but
you'll be tired from it. Endurance and pacing yourself will be important. Also,
I'll insist on immediate first aid rules as opposed to waiting for combat to
end.

as pen is related to energy/area, I used an area of 1cm^2 for blade weapons
swinging attacks to get numbers that matched GGG. I still need to experiment
with stabbing, but .1 cm^2 should work nicely ( approximately doubles the pen
for stabbing ). The fact that the numbers are fourth roots mean that there won't
be much variation at the low end of the scale. The system is not fine-grained
enough to handle such small differences.

The momentum proportional to damage does work for differentiating guns at least
( not that its very noticeable in game terms. a .45 has slightly less pen but
greater dam than a 9mm. The same is true for a .50 Hawkins when compared to a
smaller caliber rifle of similar muzzle energy. )

the new equations are simplified somewhat

pen = (me/(.7854*b^2)^.25)/4 round to nearest
dam = (2*me*m)^.25)/3

me = 'muzzle energy' or attack energy
m = mass of the attacking weapon or projectile
b = projectile diameter
area = b^2*.7854
melee blades use an area of 1 for swing attacks, .1 for stab attacks
( melee area may change )
melee blunt can be assumed to have a pen = 0 for now.

I now have to consider how to handle weapon blocks and parries.
blocks are a level easier than parries but require an AP* to ready again whereas
parries are harder but the defender can attack again immediately? Something to
think about.

* my combat variant will be action_point based with the number of action points
a player has equal to (str+dex)/3. With 5 sec turns, each action point is 1
second of action for joe normal 777777.

more another day

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PostPosted: Sat Jul 05, 2008 7:16 am 
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Quote:
my combat variant will be action_point based with the number of action points a player has equal to (str+dex)/3. With 5 sec turns, each action point is 1 second of action for joe normal 777777.
I like this... keep going... :)


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PostPosted: Sat Jul 05, 2008 7:18 am 
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Quote:
okay...I need to learn how to make pretty charts/tables. can someone tell me how please?
Yes, what do you need putting into tables?


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PostPosted: Sat Jul 05, 2008 12:55 pm 
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John wrote:
Quote:
okay...I need to learn how to make pretty charts/tables. can someone tell me how please?
Yes, what do you need putting into tables?


umm...table stuff like weapon lists, etc?
lol, I've only begun my wackiness. Just wait untill I start on my vehicle building ideas.

I figured out that I need to use the 'code' tag, but I'm not sure how to make the entries line up all nice and neat.
should I use tabs?..spaces?.. something else?
I generally write things out in kate, then cut and paste here.

thanks

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PostPosted: Sat Jul 05, 2008 2:05 pm 
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I use Notepad for all my little tables - seems to work OK.


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PostPosted: Sat Jul 05, 2008 5:02 pm 
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Ishmael wrote:
I figured out that I need to use the 'code' tag, but I'm not sure how to make the entries line up all nice and neat. Should I use tabs?..spaces?.. something else? I generally write things out in kate, then cut and paste here.

Doesn't really mater what kind of wordy programme you use, but you need to use a constant space font like Courier New. You have to use spaces to line things up, tabs don't work in the code field.

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PostPosted: Sat Jul 05, 2008 6:18 pm 
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Vile wrote:
Doesn't really mater what kind of wordy programme you use, but you need to use a constant space font like Courier New. You have to use spaces to line things up, tabs don't work in the code field.


thanks...
I always replace tabs with spaces, but I forgot about constant space fonts

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PostPosted: Sat Jul 05, 2008 10:04 pm 
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I guess I should start a bit on the game system itself...

Yet Another Version of Snapshot/AHL

This will be an action point based action game.
Grid size is 1.5m to be compatible with standard deckplans, but privately, I'd
prefer it to be 1m to make things easier for combat in areas where there are no
grids ( exteriors or among buildings,etc. tossed on a game table).
Game turns will be 5 seconds each.
Each player will recieve Action Points ( AP's) to use for movement and actions.

AP = (str+dex)/3 round to nearest

This gives 5 AP's for an average human making an AP equal to one second of
action for an average human. This is handy in cases where task times matter and
for guessing at how many AP's a newly added action should cost.
Because I use a houserule for stat dm's that involves dividing the stat by 3
instead of by 5 as per stock MT, each damage point to str or dex subtracts 1
from the AP total. This can be handy when handling npcs.

dm = int( stat/3 )-1

this gives dm that deviates from standard only in extreme cases. No
longer does a str5 guy get the same dm as a str9.
Strengths can go above 15 for aliens or augmented humans ( genetic/ cyborg/
powered exoskeletons, etc.)

Endurance can be spent to increase strength temporarily. Endurance used in this
fashion is lost until recovered by rest. Endurance is decreased by 1 for any
turn in which the player ran and decreased by 1 for any turn in which the
player was involved in melee combat. Endurance is regained by 1 per turn in
which the player performs no actions or movement. This does not include
endurance lost due to injury or wounding.

Player losses conciousness when endurance reaches 0 for any reason.

This is a way to use endurance to gain a burst of speed or make a powerful
melee attack even though it may leave the player out of breath and with
decreased endurance until the player finds a safe place to rest ( even if
only standing warily and panting in a sword-fight before continuing.)

AP's can be spent on movement even as they can be spent on actions.
A player with 5 AP's can spend up to 5 on movement actions AND up to 5 AP's on
other actions with minor limitations ( no other actions can be taking while
running ). Movement will give negative DM's to most tasks.
A player can run while shooting. A player can jump out a window while blocking.

player movement includes walk, trot, run.
A player may be prone or standing
movement costs are doubled while prone or evading.
sprinting can be accomplished by using end to increase str

Insert AP cost lists here
Code:
AP cost                action          move        turn45          turn90
    1                   walk            1.5m         0 AP            1 AP
    1                   trot            3m           1 AP            2 AP
    1                   run             4.5m         2 AP             no

I'll fill in more as I work things out in better detail.

I still need to think about melee attacks and how to make it simple. ( attack
values change as stats change and based on how many AP's the player spends on
each attack, etc. how to parry...how to block...shield, etc. )

I still need to figure out special actions and fill out the AP cost table.

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