Article View: rec.games.design
Article #505RPG - Damage System v1.3
From: Robert J. Hall
Date: Tue, 22 Dec 1992 20:51
Date: Tue, 22 Dec 1992 20:51
414 lines
19091 bytes
19091 bytes
SYSTEM-BASED PHYSICAL ATTACK WOUND METHOD
(c) Copyright 1992, Bob Hall
This is still in the development stage, so many concepts are still
loosely defined. Please bear that in mind while reading onward...
Changes: simplified target selection system. Critical wound blow-
through effects. Sample critical damage table.
INTRODUCTION
This system deals with the damage caused by a solid physical object strik-
ing a location on a body with a given velocity, angle of attack, shape,
and mass. It does not yet deal with other forms of attack, such as
explosions, acid, fire, electric shock, freezing, and so on, although it
may be possible to integrate such effects into this system.
The system is only intended to be an approximation of the actual physics
involved. No damage system can ever be completely accurate, and certain
simplifications were necessary to make it playable.
SCALE
Some of the numbers used in this damage system will be based on an expo-
nential scale. This means that for each increase in a value, the actual
quantity the value represents will be increased by a multiple. The
standard increment will be based on the size of the dice being used. For
simplicity, the actual quantity will be doubled for each dice worth of
increase to the total. For example, if a ten-sided dice is being used,
then each increase of ten is equivalent to a doubling of the factor being
represented.
Such exponential values, of necessity, must be based on a specific dice
size. A common dice size, such as 6 or 10-sided, will need to be selected
before any solid tables of weapon, armor, or creature data can be con-
structed. However, a conversion table can easily be included in the
appendix for different dice sizes.
The actual values will be in metric. Lengths are in meters, mass is in
kilograms, force is in newtons, and energy is in joules.
WEAPON TYPES
There are three standard categories of physical weapons, based on the
shape of the striking surface.
POINT - These weapons have a tapered tip that comes to a sharp point. The
tip is used to breach the surface, while the tapered sides widens the
wound as the tip travels deeper into the body.
WEDGE - The edge of this weapon is a straight or curved line. The edge
makes the initial penetration into the body, then the widening sides open
the wound while the blade slices deeper into the body. Some compression
will occur along the axis of the edge.
HEAD - The tip of this weapon is a wide flat or curved surface. The impact
will compress the surface under the head, sending shock waves radiating
from the area of contact.
Some weapons can include a combination of these different striking surfaces.
STOP FACTOR
In this damage system, some amount of the weapons kinetic energy is
expended to penetrate the external defenses of the target. The difficulty
of this penetration is given by an equivalent cross-sectional area. This
area is used to determine the stop rating of the weapon. The greater the
area, the larger the stop rating.
For a flat-headed weapon, the penetration area will be determined by the
total area of impact. Blades and points will be based on a cross-section
at some distance up the cutting edge. Sharper blade or point weapons will
have a smaller area and a lower stop factor.
The stop factor is an exponential rating. For each dice increment in the
stop factor, the equivalent penetration area is doubled. Since the area
increases as the product of two dimensions, doubling the size of a weapon
will increase the stop factor by a total of the two base dice.
DAMAGE COMPLEXITY
Damage due to weapons penetration is systems-based, meaning that the
weapon causes damage to specific systems within the body. To allow for a
range of complexities, the systems are organized in an outline format,
with each subset describing the systems in finer and finer detail.
Obviously there is a certain amount of overlap in system functions. Such
overlap will be factored in during the damage procedure.
The amount of complexity required by the GM will determine the level of
system detail required:
Level 0 - No detail
The simplest damage level treats the entire body as a single system.
There are only a few possible outcomes from a wound: fatigue loss;
staggered; incapacitated; dead.
Level 1 - Exterior/Interior
The next simplest damage level determines whether or not the weapon
inflicted damage to the exterior or the interior of the body. The
exterior includes all body systems that interact directly with the
external environment. The interior includes the remaining systems
that support the bodily functions, but only interact indirectly with
the outside environment.
Wounds to the interior have more serious effects on the target than
external strikes. External wounds will lower the combat efficiency,
while internal strikes can completely incapacitate the target.
Shown below is a Level 1 systems outline for a human:
Location Critical Damage Effects
------------- --------------------------------------------------------
External Physical skills reduced or lost
Internal Physical & Mental skills reduced or lost; Incapacitated
Level 2 - System Groups
These are groups of organs that work together to support a specific
function. External systems include weapons, locomotion, senses, and
protection. Internal systems include power, energy, and control.
Wounds to specific systems can cause reduction or loss of specific
functionality. Critical wounds can cause damage to multiple systems.
Shown below is a sample Level 2 systems outline for a human:
External Primary Combat Function Sample level 3 systems
------------- ------------------------------- ----------------------
Protection Protects the body from damage Skin, bones, tissue
Mobility Allows the body to move rapidly Legs, feet
Weapons Make attacks or ward blows Arms, hands, and teeth
Sensors Observe opponents and obsticles Eyes, ears, nose
Miscellaneous Distraction Hair, sexual organs
Internal Primary Combat Function Sample level 3 systems
------------- ------------------------------- ----------------------
Power Maintain activity level Heart, lungs, arteries
Energy Recover from fatigue Stomach, intestines
Command Control the other systems Brain, spinal cord
Miscellaneous Special Glands
Level 3 - Individual Systems
These are specific organs or groups of tissue that perform a dedicated
task. Such systems include the heart, lungs, brain, stomach, hand, eyes,
ears, shoulders, and so on.
Detailed descriptions are given for serious and critical wounds against
each system.
Level 4 - System Components
These are the bits and pieces that go together to make up an individual
system. Components include thumb, cornea, heart value, etc. This level
of detail is probably unnecessary for most purposes.
The local medical library is available for determination of the wound
effects. (Sorry, no 'humor impairment' critical result.)
WEAPON DAMAGE
The kinetic energy of the weapon is determined by the success of the
attack and the attributes of the attacker. An inept or partially blocked
attack will have a lower energy than normal. Likewise, a weak or fatigued
attacker will be unable to propel the weapon as rapidly.
The weapon will strike at a specific location on the body. If the location
is an external system, then the kinetic energy of the weapon will be
expended in the form of damage to the selected system. When a strike is
made at an internal system, part of the energy is expended to penetrate
the external protection system.
Each internal system will include an external protection rating which
determines how many damage points must be spent in penetration. The weapon
stop factor will determine how many additional damage points are spent as
concussion energy against the external protection. The remaining amount is
the number of damage points inflicted on the internal system.
The Damage point total is an exponential rating. For each dice increment
in the Damage points, the equivalent kinetic energy is doubled. Each dice
worth of Damage points absorbed by a system will half the Kinetic Energy
of the weapon.
SYSTEMS TABLE
During each attack, the attacker makes as success roll for each weapon
employed. Each of the defenders systems has a skill difficulty rating that
determines the difficulty to hit that target. The attacker declares the
target prior to the attack, then the skill roll is made at the target
difficulty. If the attack is hasty, or no target is selected, then the
protection system is chosen as the default. If the attack gets past
the defenses, the resullting level of success determines if the selected
target has been struck.
Each creature or character will have a systems table which will display
various combat factors for each system. A sample table is shown below:
Difficulty External System Serious Critical Armor
---------- --------------- ------- -------- -----
Average Protection 10 20
Hard Mobility 6 12
Average Weapons 5 8
Very Hard Senses 1 2
Hard Miscellaneous 3 10
Difficulty Internal System Serious Critical Protection Armor
---------- --------------- ------- -------- ---------- -----
Very Hard Power 1 2 4
Hard Energy 2 4 2
Very Hard Command 1 2 3
Hard Miscellaneous 2 5 2
The first column is a percentile table that is used to select a system at
random. Of course, some other dice can be used, as long as the values are
roughly proportional. The second column is the modifier to the skill level
when the attacker targets that specific system. The third column is the
name of the system. The fourth column is the number of damage points
needed to inflict a serious wound to the system. The fifth column is the
number of damage points needed to inflict a critical wound. The sixth
column of the internal damage table is the external protection level for
the specific system.
ARMOR
When external armor is worn, each system receives an Armor rating that is
entered in the systems table. The rating is the number of damage points
absorbed by the armor prior to any wound determination.
Each piece of armor provides different numbers of Armor points to
different systems. A Helm, for example, could provide 20 points to
Command; 15 to Senses; 5 to external Miscellaneous; and 5 to Protection. A
separate table is used to record each piece of armor worn, and the number
of points provided to each system. The Armor points are totalled for each
system, and the results are then entered under the Armor columns in the
appropriate rows of the systems table.
Armor that is designed to cushion an impact will have higher ratings for
the External systems. Likewise, armor designed to prevent penetration will
have higher ratings for the Internal systems. (Possibly each piece of
armor could include a damage overload factor - the level of damage points
needed to break the armor. Not sure how to include this, however.)
For the sake of simplicity, complete suits of armor will be described
using the total Armor points in each system. (This is instead of a
complete listing of the armor components and the points each provides to
the various systems.) A complete equipment list will, however, still
describe individual pieces of armor.
WOUNDS
There are three wound categories:
MINOR - Easily repaired wounds that have a minimal impact on the body
performance. Many such wounds will increase fatigue and impact the
overall health.
SERIOUS - A wound that is detremental to the performance of a system. The
system will continue to operate at a reduced level of efficiency. (Halved,
or reduced by some penalty - depending on the game system.) The effect
on the creature or character will depend on the specific system impacted.
For a level 2 damage system, the effects of a loss of system effective-
ness would be as follows:
Protection Reduced ability to absorb internal damage
Mobility Loss of speed and agility
Weapons Decrease in combat weapon/shield skills
Senses Temporary loss of sight, hearing, etc.
Power Reduction in actions per round
Energy Unable to recover strength
Command Stunned, dizzy, paralysis, and/or unconsciousness
Miscellaneous Special effects.
CRITICAL - A very nasty wound that seriously disrupts the target system.
The special effect will be determined by a critical wounds table for the
system. (Separate critical wound tables will be needed for each level of
complexity.) Some critical wounds will cause additional damage to other
systems due to weapon penetration. The systems effected would be listed
in the customized critical wound descriptions.
When damage is applied to an internal system, the damage to external
protection is always computed first to determine if any Critical wounds
occur. Such critical wounds can impact the resulting amount of damage to
the internal system. For example, suppose the blow is to the Power system.
If the external damage is sufficient to cause a critical wound, then
damage beyond the critical level is also applied to the Power system. This
could be interpreted as smashed bones that no longer protect the Power
system - resulting (for example) in a crushed rib cage and collapsed lung.
BLOWTHROUGH
The damage points beyond the critical damage level are called blowthrough.
These are applied as a new wound to the system specified in the critical
damage table. Here is a sample critical damage table for level 2:
System Critical Hit Effect*
------------- -----------------------------------------------------
Protection Serious and Critical damage levels are halved.
Mobility Leg is crippled. If blowthrough damage is sufficient
to cause another critical wound, then leg is severed.
Roll on the table below to detemine the location:
1d10 Location**
------- ----------
1-2 Hip
3-5 Thigh
6 Knee
7-8 Lower Leg
9 Ankle
10 Foot
Weapons Arm is crippled. If blowthrough damage is sufficient
to cause another critical wound, then arm is severed.
Roll on the table below to determine the location:
1d10 Location**
------- ----------
1 Shoulder
2-4 Upper Arm
5 Elbow
6-7 Lower Arm
8 Wrist
9-0 Hand
Senses The sense is completely lost. Blowthrough damage is
applied to the Command system. Roll on the table below
to determine the sense lost:
1d10 Location
------- ----------
1-3 Eye**
4-6 Ear**
7-8 Nose
9-0 Tongue
Power Immobilized. Blowthrough damage is applied to Energy.
Energy Stunned. Blowthrough damage is applied to Power.
Command Immobilized. Blowthrough damage is applied to Power.
* On all critical hits, a Willpower roll must be made on each round
thereafter for the character to remain conscious.
**Random roll to determine the side damaged.
IN GAME TERMS
As a minimum, all creatures include a Level 1 systems table describing the
External and Internal systems. Where further detail is required, the
wounds table can be expanded to higher levels of complexity. Each level of
table should be kept separate for easy access, and the values for each
wound system should be the weighted average of the values from the more
detailed wounds system. For character races, the wounds table should be
developed to at least level 3, with level 1 and 2 tables included as well.
At level 3 or above, additional details can be included for the various
body systems - especially for critical wounds.
The following outline describes the damage process for level 1:
1. Determine the total damage points.
2. If the damage is internal, check for external damage.
a. The Protection rating of the internal system, plus
b. The Stop rating of the weapon.
c. Perform steps 4 & 5 below for the external damage.
3. Deduct the artificial armor protection.
4. Check if each wound is minor, serious, or critical.
a. For minor wound, increase fatigue.
b. For serious wound, decrease skills and/or stats.
c. For critical wound, determine effects from table.
OTHER ADDITIONS?
- Damage from other sources. Fire, cold, electricity, acid, etc.
Fire, cold, and acid should probably be external type damage, while
electricity effects the control system in addition to whatever else
it fries.
- Different difficulty ratings for other hex sides. I.e. modify system
odds for front, flank, rear, etc.
Constructive comments, additions and revisions are welcomed.
--
Bob Hall | if [ -bs message ]; then
Boeing Computer Services | mv message /compost/heap/$$
root@chicken.ca.boeing.com | fi
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Newsgroups: rec.games.design Path: arc1-ca.pugleaf.net!sparky!uunet!bcstec!hall From: hall@bcstec.ca.boeing.com (Robert J. Hall) Subject: RPG - Damage System v1.3 Message-ID: <BzoHyn.wA@bcstec.ca.boeing.com> Organization: Boeing Date: Tue, 22 Dec 1992 20:51:58 GMT Lines: 414