The Way, The Truth & The Dice: Volume 1, Issue 1


Hitting Them Where It
Hurts

by Charles Franklin


I was watching a classic science fiction film this weekend with my four-year-old son and one scene in particular emphasized the way combat is portrayed in movies and in our games. In this particular scene an alien, accompanied by a starship pilot and a teenager, wander into a detention zone where a firefight erupts with the evil military police. Now granted, the threesome had the element of surprise, but when the shooting starts they calmly go about their business, zapping security cameras and bad guys with amazing accuracy. Meanwhile the trained military police can’t seem to hit anything. Common sense tells us that this is a less than accurate portrayal of how this firefight would occur, and I think everyone realizes that Hollywood takes great liberty with reality in their action movies. This cinematic liberty carries over into RPGs that for the most part seek to model movies, not reality.

The purpose of this series of articles is not to open a debate about the glorification of violence in popular movies and role playing games. I do believe, however, that adding a dose or two of reality to our game mechanics will reduce the quantity of violence and increase the quality of role playing. I see this as a win-win adjustment.

Let me start with damage, wounds and hit points. The idea that a person can be subdivided into a number of equal “hit points” that measure their ability to withstand physical damage is convenient for writing game mechanics. It is also a significant departure from reality that has been criticized by many writers. It fosters reckless behavior by characters with a large number of points. I believe it encourages “hack and slash” role-playing with players only resorting to non-violent conflict resolution when they have burned up most of their hit points. Defining a more realistic damage model presents a few problems. First of all, most of the more realistic game mechanics that I have seen involve a lot of cumbersome rules and math. Second, what yardstick do we use to define “realistic”?

My solution is to make use of Colonel Trevor Dupuy’s Historical Evaluation and Research Organization (HERO) database. Col. Dupuy, USA (ret) is a decorated W.W.II combat veteran and a prominent military science theorist. He has spent many years working on a quantitative model for modern combat. As part of that effort, he has created a database that covers literally hundreds of actual 20th century engagements, from World War I to the Gulf War. One product of this research has been an analysis of personnel attrition. The bulk of the data used in this article is drawn from the “73 Engagement Post-1945 Conflict Data Base” that spans actions from Indonesia 1946 through Lebanon 1982. He has written several books on this analysis and presented numerous papers to various professional military organizations.

Now this is certainly a sound, reputable source for realism, but how do we apply this analysis to our game mechanics and how will it affect game play? That’s our challenge. In this article I will avoid addressing specific game systems and will convert Colonel Dupuy’s analysis into percentages. GM’s who want to try including this information in their games can either roll percentile dice or convert the percentages to a preferred dice type. Fair warning: this article has a lot of percentages drawn from the real world HERO database. If you are overwhelmed by math and statistics, then look out!

Let’s start with the basics. According to Col. Dupuy’s data, 20% of people wounded by a modern firearm on the battlefield will be killed outright if they are not wearing body armor. Let’s call that a KIA (Killed In Action) result. 15% will be incapacitated, an INC (Incapacitated) result. The incapacitated require immediate medical attention, may eventually die of their wounds and for game purposes are out of action. 65% will be simply wounded, WIA (Wounded In Action); these will most likely survive their wound even without professional medical attention and can remain active in the current firefight, with some penalties.

What if the target is wearing body armor? These numbers are a bit fuzzy. The KIA percentage is only reduced to 14%; the INC percentage remains 15% and 71% are “only” wounded. These numbers always seem to shock the reader. “Body Armor only adds 6% to your chance to survive?” is the usual response. Well, not exactly. Body Armor defeats some hits outright. In essence the wound is reduced to a negligible but painful bruise. But in the HERO database soldiers only “bruised” are not included in the casualty lists. In other words, there is no casualty classification “saved by Body Armor.” Look at it another way, though. Even ignoring the armor’s ability to completely stop some hits, without body armor the ratio is 1 killed to 4 wounded. With body armor the ratio becomes 1 killed to 6 wounded. If you’re one of those extra casualties, body armor is well worth the weight!

How effective is body armor, then? In the case of your standard issue ballistic vest, fairly effective. In the case of your ballistic helmet, not very. A vest will defeat about 75% of shell fragments (including shotguns and grenades) and 25% of firearm hits. Helmets are not nearly as helpful. A helmet will defeat about 25% of shell fragments and only 4% of firearm hits.

You want more detail, you say? Okay, how about hit location. The HERO database indicates that 21% of all hits are scored on the head, 21% in the torso and 58% on the arms or legs. A GM could use these numbers to generate hit locations or to modify the preferred game system ‘s hit location system. As I’ve said before, these numbers are drawn from actual 20th century combat casualty statistics. There may be some concern that this hit location distribution reflects soldiers that are prone or in cover. Being prone or in cover would increase the number of head and arm wounds. I discount these concerns for two reasons. One, roughly 50% of modern casualties are caused by exploding shell fragments (Artillery, Hand Grenades and other explosives). Shell fragments typically come from indirect fire weapons that explode above or behind the target. Two, most firearm casualties occur in the first few seconds of a firefight, before the combatants have had the opportunity to find cover. I believe these percentages are an accurate representation of hit location distribution but the GM is free to make that decision for themselves and use their preferred game system hit location determination.

How does hit location effect wound severity? You’ve heard the old real estate saying, “Location, location, location”? Here is the proof that this saying is not limited to real estate prices:

Wound Severity Table, No Body Armor
  KIA INC WIA
Head Wounds  01-44% 45-59% 60%+
Torso Wounds 01-39% 40-54% 55%+
Other Wounds 01-04% 05-19% 20%+

Wound Severity Table, With Body Armor
  KIA INC WIA
Head Wounds w/ Helmet  01-31% 32-46% 47%+
Torso Wounds w/ Body Armor 01-27% 28-42% 43%+
Other Wound locations use the standard no body armor table.

Now let’s begin to apply this to our games. The GM only needs to add one or two die rolls to the damage resolution routine to achieve much more realistic results. When a character is shot with a firearm, first determine hit location. The GM could use the percentages included in this article or use the normal hit location according to the game system they are using. If the character is hit in a location protected by body armor, one additional die roll is required to see if the armor defeats the hit outright. If the hit penetrates the armor or if there is no body armor, the GM now rolls on the appropriate wound severity table. This could be a simple percentile dice roll or the percentages could be converted to a preferred dice type (e.g. 01-44% could just as easily be 1-9 on a d20 or 3-9 on 3d6). A KIA result is self-explanatory. An INC result means that the character is down and out of this firefight. I usually allow player characters to survive as long as they receive medical attention. Non-player characters have a survival chance of about 75% assuming they eventually receive treatment by modern medicine (c. 1999). On a WIA result, a GM has two choices. One is to apply the normal weapon damage to the character’s hit points or whatever damage mechanic is used in their game. If necessary, reduce the damage to make sure that the character is only wounded, not killed. As a rule of thumb, I would make the maximum damage that could be suffered from a WIA result equal to one half the character’s starting hit points. This will make some wounds more severe then others without the chance of getting knocked into the “one hit point club” on the first WIA. As an alternative, the GM could use a flat rate of one quarter of the character’s hit points (or whatever) for each wound. In other words, if a character has 12 hit points, they take 3 for each wound suffered that doesn’t result in a KIA or INC result. In most game systems this means that the character will collapse from their wounds after suffering their fourth WIA.

Motivated GMs could take this data a few steps farther by incorporating various modifiers as a result of campaign specific weapons and armor. The data that supports this article assumes modern military rifles being fired at average soldiers on a modern battlefield. If your campaign’s focus is pistols and submachine guns, you can model these weaker weapons by applying a penalty to the wound severity die roll. The penalty can be consistent with the game system’s weapon damage rating. For instance, if rifles have a damage rating of 5d6 and you are assessing the penalty for a pistol that has a damage rating of 3d6, I would probably add a 10% penalty to wound severity rolls using the pistol. The flip side of this penalty would be a severity bonus for very powerful weapons. If you’re assessing the modifier for a machine gun that has an 8d6 damage rating, this bonus might be a -15% on wound severity rolls. Likewise, if your campaign involves non-human races or augmented humans, you might develop wound severity modifiers based on super strength or toughness.

Future developments in body armor could cause a problem with these figures. One way to resolve this situation is by assuming that body armor technological developments will be accompanied by more effective weapon development. In other words, in a science fiction realm “blasters” might replace rifles as the standard issue military small arm. These troopers might also be wearing fully enclosed “storm trooper armor” as well. My suggestion is that small arms and body armor at a common tech level should yield about the same results as the HERO database. Storm trooper armor would then stop about 25% of all blaster hits. Blaster hits that defeat the armor or that strike an unarmored area would need a bonus adjustment on wound severity rolls based on how more effective they are than standard 20th century military weapons. Most modern and science fiction games provide damage data for a 1990s technology rifle as well as more futuristic or powerful weapons. Use that damage rating as the standard and assess severity modifiers as described above.

That’s all there is to it. With the addition of one or two die rolls, the whole flavor of any game can become more realistic. Johnny Dangerous will think twice about his “OK Corral” tactics if he knows he’s got a chance of being killed outright with any given hit. You may find that your players will begin to sit lower in their chairs and have a tendency to demonstrate how carefully they are taking cover before they reach for the dice. The tension of having a character wounded is increased dramatically!

One last warning: this system is not forgiving. The best, most skilled characters can be killed in an instant. That’s realistic. It is a game though, and no one likes to scrap a character as a result of one bad dice roll. I usually allow player’s to convert KIA’s into INC’s at the cost of losing most or all experience for the current adventure. This may seem steep, but they are lucky to be alive! In military campaigns, I normally encourage the players to control a four man fire team rather then individual characters. In the unfortunate situation that a player character is knocked out of action, the player may still participate in the gaming session. It also adds some realistic decision dynamics to the game as player’s must face splitting the team or getting wounded comrades medical assistance during a firefight.

Next time, I’ll look at the Friction of War, combat experience and those OK Corral tactics that are so dear to both Hollywood and hack ‘n slashers...

 

Dupuy, Trevor N. *Attrition: Forecasting Battle Casualties and Equipment Losses in Modern War.* Fairfax, Virginia: HERO Books, 1990.

Applying Hitting Them Where it Hurts to GURPS

Here's a sample application for Steve Jackson Games' popular multi-genre GURPS game system.

First, let's analyze the GURPS standard hit location table. If the standard hit distribution is close to the realistic hit location distribution, we'll leave it alone. Hey, if it's not broke, don't fix it!

Standard GURPS Hit Location (roll 3d6):

3-4 Brain
5 Head
6 Shield Arm
7 Hand
8 Weapon Arm
9-11 Torso
12 Far Leg
13-14 Near Leg
15-16 Foot
17-18 Vital Organs

This equates to a hit location distribution of 4.7% Head Wounds, 38.5% Torso Wounds and 56.8% Other Wounds. "Houston, we have a problem!" I'm not sure what the standard hit location distribution is based on, but it obviously places too many hits on the torso and not enough on the head. I'll adjust the GURPS hit location table to the following:

Table 1 - Modified GURPS Hit Location (roll 3d6):

3-5 Brain
6-7 Head
8 Hand +
9-10 Arm +
11-12 Torso
13-15 Leg +
16 Foot +
17-18 Vital Organs

+ Roll an additional d6:
1-3 Left, 4-6 Right

This keeps the spirit and feel of the original GURPS hit locations but alters the distribution to more accurately reflect actual data.

GURPS is a game system which predominantly uses 3d6 rolls, so I'll convert all of the wound severity table percentages to a 3d6 system. GURPS also favors low rolls. In other words, rolling a '3' is almost always preferable and rolling an '18' is usually bad. It's important to keep the application consistent with the basic game mechanics whenever possible. This will prevent your players from getting overwhelmed or confused by new mechanics.

The basic wound severity tables thus become:

Wound Severity Table, No Body Armor
  KIA INC WIA
Head & Torso Wounds 3-9 10-11 12+
Other Wounds 3-5 6-7 8+

Wound Severity Table, With Body Armor
  KIA INC WIA
Head & Torso Wounds 3-8 9-10 11+

Let's simplify it a bit by combining it into one table with some specific modifiers:

Table 2 - Wound Severity (SEV):
Roll 3d6

3-9 KIA
10-11 INC
12+ WIA - Target takes 3 hits of damage or standard GURPS damage roll (GM's option)


SEV Modifiers:
+1 if target is wearing body armor
+4 if target is hit in the extremities (arms, hands, legs and feet)

Now let's consider special weapons and body armor. Standard modern military issue body armor would defeat hits from modern rifles on a roll of 13-18 on 3d6. So for consistency:

Table 3 - Hit Penetration (PEN):
Roll 3d6:

13-18 Hit Defeated

PEN Modifiers:
+4 if the target was hit by shell fragments or a shotgun
-3 if the armor is a helmet.

The standard modern military issue small arm has a damage of 5-6 dice in the GURPS system. Lets create some modifiers for specific weapon caliber's or advanced body armors included in the basic rulebook.

Table 4 - Weapon Modifiers to Wound Severity and Hit Penetration:

Caliber Gurps Damage Wound Severity
Mod (SEV)
Armor Penetration Mod (PEN)
.45 ACP 2d +1 +2
.44 Mag 3d +1 +1
5.56 mm 5d +0 +0
7.62 mm 6d +0 -1
Blaster 6d +0 -1
.600 Nitro 6d +0 -2
Blast Rifle 6d +0 -4

These modifiers could be shortened to read Blaster: 0/-1, or for more clarity, Blaster: 0s/-1p

Table 5 - Armor Modifiers to Hit Penetration:

Body Armor PEN
Vietnam Era Flak Jacket -1
Modern Military Body Armor 0
w/ Steel or Ceramic Plate Inserts +2

Finally, the average human in GURPS has a Health/Hits attribute of 10-12. I would add an additional modifier to the wound severity table based on the target's Hits. (In some cases, GURPS makes a distinction between Health and Hits, this modifier would apply to Hits in these split attribute cases.)

Table 6 - Wound Severity Modifers for HT:

HT SEV Modifier
1 -2
2-8 -1
9-13 0
14-20 +1
21-32 +2
33-56 +3
57+ +4

Simply add three small tables and a relatively short list of modifiers and your GURPS games will generate hit locations and wounds comparable to historical trends in modern warfare.