"Better" Combat Systems in RPGs - Feedback Welcome!

[Jd Smith1]

To your second point, I have found that a great part of the attraction of "roleplaying" over "real life" for some people is that the randomness of what things you suck at/what gifts you have is actually up to you to determine. YMMV.

That's really sad.

 

[GMMichael]

@Bilharzia that typo is hurting my eyes

So, my personal bias would be to call it "defense" and give the player the option to boost it with both parry bonuses (which are easier to acquire) and dodge bonuses (which are less available). And rule that the defense bonus from fighting skill is a somewhat nebulous mix of both those things and reading your opponent. The total defense action would probably involve a combination of parrying and dodging (stepping back, sideways, out of range, etc.).

Defense rules can get out of control if you don't keep them on a tight leash. Just a heads up. Here's how mine went haywire:
1) Characters can take a set amount of "damage" before they're out of combat. Increasing this amount is effectively more defense.
2) To avoid all damage, a character can react to an attack with a defense action. A defense action uses a defensive skill, of which Parry is one.
3) To avoid some damage, a character can wear armor which reduces all incoming physical damage.
4) To avoid some damage from certain weapons, a character can change posture with a movement action. This is like taking a defensive position.
5) The above-mentioned movement action uses a Movement skill, which can include dodging.

So here I have 5 different ways to avoid dying in a fight. And a design goal was simplicity. You might not need to add Total Defense, because you might already have more defenses than you think

 

[Bilharzia]

@Bilharzia that typo is hurting my eyes

?

 

[dragoner]

Armor Class is realistic enough, this is a materials strength graph showing the typical energy curve, a curve often repeating through physics as it really shows the conservation of energy (or momentum in this case). Basically if a projectile or thrust has enough energy to penetrate the material, it would do full damage. There are other carry on effects, such as a projectile rebounding off the back armor to do more damage, except the one roll to see if one does damage is slightly faster than a roll to hit and them rolling to do damage. An armor penetration that then does little damage is fairly unrealistic, as the graph shows.

 

[Bilharzia]

...

 

[aramis erak]

An armor penetration that then does little damage is fairly unrealistic, as the graph shows.

Which would be true if damage to, say (assuming all fired from the same position), the lung had the same net effect as damage to the pocket of the shoulder, or the side of the ribs, or the thigh. There's good reason the trauma plate isn't huge on class two-plus armor; it's there to protect direct shots from front aspect to the heart, aorta, and vena cava.

The difference between a lethal thigh hit and merely temporary disability thigh hit is measured in single digit millimetre differences in location. Likewise the pocket of the shoulder - if the stretch cavitation doesn't rip open the major arteries and veins, those locations are impairing, but not lethal, and full function (≠ full healing, mind) can be, depending upon exact path, a few days to a couple months. Open the major veins or arteries, either by stretch cavitation exceeding elastic rebound of the vessel, or by penetrator actually directly slicing, and life expectancy is minutes, with potentially little to no disability prior to vascular collapse from lack of blood volume. Which can be seconds to double digit minutes, depending upon which vessel and where along it. At the same time, said vascular hit can result in major loss of long-term disability by tissue damage from oxygen deprivation and/or inability to restore supply before necrosis and/or infection.

It's also not unlike how a few inches difference in a fireplace log to the underbody of a truck... if it pops the air brake line (pulling it from the connector, cracking the connector, or snapping the hose, the rig's going to stop, and possibly damage the transmission. If it cracks the transmission case, it may do very little damage. If it hits the frame, it's unlikely to matter as a single impact. If it hits the fuel tank, it's a slow loss of function, but one that can be easily patched on the fly once the tank is dry with epoxy or self-bonding metal alloys. The loss of fuel is potentially expensive, especially given a $10 patch... or a $100-$200 welding job by a shade-tree mechanic, and more for a proper heavy equipment repair shop. Hit the engine block? may in fact kill the engine, and not even that month...

The average effect of a .223 Remington/5.56mm NATO to the clothed unarmored chest is a potentially lethal bleed and a roughly 30% one shot stop chance; the end results without body armor have varied from lodged in a bone with little to no significant bleeding (a dozen cc or less) to an aortic dissection and near instant kill, with sufficient shock effect to render the individual incapable of response with force. Given that few games get more detailed than the Chaosium and GW set (Head, Chest, Abdomen, 2×arm, 2×leg), and most only track location for armor, not wounds, random damage after penetration does make perfect sense.

 

[Campbell]

One of the biggest issues with properly reflecting human athleticism (which is particularly important if realistic combat is in any way desirable) is that most games ignore the way energy systems work. Completely evading rather than defending from attacks is generally more energy intensive. It absolutely can be done and may be worthwhile (especially if you can get to someone's side), but it is taxing if not always difficult.

 

[dragoner]

Which would be true if damage to, say (assuming all fired from the same position), the lung had the same net effect as damage to the pocket of the shoulder, or the side of the ribs, or the thigh. There's good reason the trauma plate isn't huge on class two-plus armor; it's there to protect direct shots from front aspect to the heart, aorta, and vena cava.

The difference between a lethal thigh hit and merely temporary disability thigh hit is measured in single digit millimetre differences in location. Likewise the pocket of the shoulder - if the stretch cavitation doesn't rip open the major arteries and veins, those locations are impairing, but not lethal, and full function (≠ full healing, mind) can be, depending upon exact path, a few days to a couple months. Open the major veins or arteries, either by stretch cavitation exceeding elastic rebound of the vessel, or by penetrator actually directly slicing, and life expectancy is minutes, with potentially little to no disability prior to vascular collapse from lack of blood volume. Which can be seconds to double digit minutes, depending upon which vessel and where along it. At the same time, said vascular hit can result in major loss of long-term disability by tissue damage from oxygen deprivation and/or inability to restore supply before necrosis and/or infection.

It's also not unlike how a few inches difference in a fireplace log to the underbody of a truck... if it pops the air brake line (pulling it from the connector, cracking the connector, or snapping the hose, the rig's going to stop, and possibly damage the transmission. If it cracks the transmission case, it may do very little damage. If it hits the frame, it's unlikely to matter as a single impact. If it hits the fuel tank, it's a slow loss of function, but one that can be easily patched on the fly once the tank is dry with epoxy or self-bonding metal alloys. The loss of fuel is potentially expensive, especially given a $10 patch... or a $100-$200 welding job by a shade-tree mechanic, and more for a proper heavy equipment repair shop. Hit the engine block? may in fact kill the engine, and not even that month...

The average effect of a .223 Remington/5.56mm NATO to the clothed unarmored chest is a potentially lethal bleed and a roughly 30% one shot stop chance; the end results without body armor have varied from lodged in a bone with little to no significant bleeding (a dozen cc or less) to an aortic dissection and near instant kill, with sufficient shock effect to render the individual incapable of response with force. Given that few games get more detailed than the Chaosium and GW set (Head, Chest, Abdomen, 2×arm, 2×leg), and most only track location for armor, not wounds, random damage after penetration does make perfect sense.

Random damage is fine. It is just that if your end state is no or minimal damage, then the extra work rolling damage, and/or hit locations is wasted, increasing the amount of time spent rolling for combat. All those rolls add up, and increasing a grind type combat can easily take the time from 45 minutes to an hour and a half.

The other point is that conservation of momentum would state that if armor is penetrated, then the armor would not be considered in the damage, that is what the graph shows.

That is why I said it is realistic "enough", not perfect, except if given two mechanics, and both produce similar results, the faster one is better.

Strangely enough, looking at all the games I have run lately, most are BRP, with some Traveller. I wouldn't really consider myself a BRP GM, yet here we are.

 

[aramis erak]

Random damage is fine. It is just that if your end state is no or minimal damage, then the extra work rolling damage, and/or hit locations is wasted, increasing the amount of time spent rolling for combat. All those rolls add up, and increasing a grind type combat can easily take the time from 45 minutes to an hour and a half.

The other point is that conservation of momentum would state that if armor is penetrated, then the armor would not be considered in the damage, that is what the graph shows.

That is why I said it is realistic "enough", not perfect, except if given two mechanics, and both produce similar results, the faster one is better.

Strangely enough, looking at all the games I have run lately, most are BRP, with some Traveller. I wouldn't really consider myself a BRP GM, yet here we are.

Given our discussions over the years, you using BRP doesn't surprise me.

I will say that, in armor, I've taken hits that have damaged the armor, but not me inside it. ANd hits that did damage me but not as much as they should. Case in point (intentional pun), I did a hand parry that took a chop and converted it into a slash while fencing (rapier) - the nicks from the days fencing resulted in a serration, which opened a slice through the 8oz leather glove, but not into the webbing of the thumb, tho' it did leave a small surface scratch. Likewise, fighting SCA Heavy, I took a hit to the arm which bent the brass rings of the ring-on-leather¹ I was wearing, but didn't break my arm; instead, it left a 4" × 2" bruise in the pattern of the rings.

1: ring on leather is rings sewn to leather, not mail over leather.

 

[Jd Smith1]

I believe that to model the tactical effect of combat well, you would need to track will, blood loss, and structural damage.

Many people simply quit when they get hurt; I've seen this both in the military and in law enforcement. In game terms, I would restrict this to NPCs, as reducing character motivation to a die roll for a PC would not be a good idea.

Adrenaline, raw emotion, and drugs can and has kept people fighting after a mortal wound is inflicted, but a broken bone or cut tendon cannot be completely overcome (in most cases). And when your blood pressure drops to a certain point, you're going down.

I've yet to find an effective way to model this, but the dream lives on.