Wow, this is quite a lot to take in and I must say, it seems promising on first read.
I have a few remarks:
What's your thought process here and why does the effect of penetration on DR differ so much depending on the type of damage?[/quote]
Frankly, I thought about it for a while and decided I wanted to do it two ways for DR and RE, and didn't want any two categories to be the same because I wanted the categories to mean something. As for which got which, it made sense to me at the time, and some still make sense. For instance, penetration for kinetic weapons more or less amounts to momentum/area. (Or, for concussive damage, it's just pressure.) So a kinetic weapon with double penetration either has twice as much momentum and would be slowed down half as much by any defence, or it's over half the area and would only encounter half as much resistance. For an energy weapon, penetration is also a factor of concentration, but they don't have any momentum to keep them focused and would diffuse. So any amount of extra concentration would only do so much to reduce the effect of a defensive measure before the energy spread out.
Have you thought about factoring in the angel of penetration, with projectile damage, this is a huge factor.
The sine of the angle of penetration could be a multiplier for the penetration and for kinetic damage it would also be a multiplier of the concussion damage.
I'm not sure if you have anything in place to calculate whether an attacking bounces off the armor, but it could be very interesting to see a powerful attack bounce off a set of armor with high DD and hit another target.
The calculations here should be rather simple, you do a check of the P multiplied by the sine of the angel of the P against the DD. If it bounces, you calculate the concussion and the new direction and KE of the projectile.
Well, here I'm just not sure the engine can handle it. Even if it did, it's a bit harder to code and it's yet another thing for the player to keep track of. (The rules are complicated already.) That's not a "no," just a "maybe."
It seems that the system you have in place now doesn't allow for dinging as the PF is always a positive number.
Well, that's not quite true. Even if you do always get some penetration on an object, this comes before DR and RE have their say. If there's significant DR, you'll need a certain amount of penetration not to be left dealing 0 damage.
In any case, this is very interesting and a few examples would be nice.
I'll try and run the gambit here. Five weapons, five targets. Sticking to smaller weapons (infantry weapons and one moderate-power spell) because that's the most relevant, but I'll go all the way up to tanks on the side of the target. (If it's of any use, it'll be to show what these things can't do.) I'll use weapons from multiple genres, but stick to five example targets that are real-world, generic or not too terribly different from their real-world equivalent.
Terminology notes: Puncture damage is abbreviated as "L." This stands for "laceration." This is to avoid confusion between it and penetration in its abbreviation. This is a recent change. And by "recent" I mean "I realized there was an issue, and changed it as I was writing this." Concussive damage is abbreviated "K" as in "Kinetic" and thermal damage is abbreviated "X" as in "Exothermic" or "N" as in "Endothermic," depending on whether it is high or low temperature that is causing the damage. The other damage types are incision (I), bludgeon (B), electric (E), chemical © and ionizing ®, but none of those are relevant.Target A: Bare human torso: (Adult, base stats, no relevant bonuses)
LDD 0.6, LDR 10,
KDD 0.1, KDR
, XDD 1.1, XDR 10,
Skin is not counted in-game without investing feats, perks and/or having a special species ability because it wouldn't do a damn thing.
EDIT: I initially wrote 2/2%, but that's not correct. Also, RE has been removed entirely since this was written.Target B: Combat Armour: (Medium armour, ballistic, basic quality, not on the plate)
LDD 1, LDR 10,
KDD 0.1, KDR 1,
XDD 0.1, XDR 10,
XRE 10%Target C: Thick generic automobile door: (military truck, steel, manufacture date ~2015)
LDD 3, LDR
KDD 0.3, KDR
XDD 0.15, XDR
Special: Double layered, must be penetrated twice to pass through.
EDIT: This is metal armour, so it has double DR. I forgot that the first time I did this.Target D: HMMWV door: (without up-armouring, manufacture date ~2015)
LDD 15, LDR
KDD 1.5, KDR
XDD 0.75, XDR
Vehicular composite armour, which is like metal armour in its stats but much more so. The stats were mostly right, but the DR was wrong.Target E: U5A1 Whiplash LST frontal aspect: (without up-armouring, manufacture date ~2015)
LDD 50, LDR
, KDD 5, KDR
, XDD 2.5, XDR
(It is not *technically* invulnerable, but for our purposes it might as well be.)
EDIT: All of the following calculations have been fixed. There is no strikethrough text for the old values because it was screwing me up.2.5" #1 buckshot (7.62mm ball)
L 120, KE 15, P 0.33 (Very strongly under-powered, but depending on what weapon you're using you may be firing anywhere from 7-15, and a common 12 guage fires 10. Still shit against armour.)
Velocity is ~340m/s, and if the engine will allow it, this will actually decrease in proportion to its loss in penetration as it flies and each time it penetrates a target. Then, of course, there's gravity. Not a simple point & shoot game if you're at any significant range.
L. 0.33/0.6=0.55, 120*0.55=66. 10/0.33=30. 66-30=36. 36 puncture damage.
K. 0.33/0.1=3.3. (P>KDD, full damage. New P is 0.23.) 4/0.33=12. 15-12=3. 3 concussive damage.
Total 39 damage.
L. 0.33/1=0.33, 120*0.33=40. 10/0.33=30. 40-30=10. 10 Puncture damage. (To the armour itself, not the wearer. The wearer is not punctured.)
K. 0.33/0.1=3.3 (As above, full damage. New P is 0.23.) 1/0.33=3. 15-3=12. 12 concussive damage. (The wearer will take 12 K with 0.23 P. If they are as above, after all resistances they will take 3 concussive damage.)
Total 22 damage.
L. 0.33/3=0.11, 120*0.11=13. 60/0.33... We can stop here, can't we? We know it'll be 0 puncture.
K. 0.33/0.3=1.1 (Basically meaningless 0.1p left.) 15*1=15. 6/0.33=18. 15-18=0. 0 concussive damage.
Total 0 damage.
Congrats, you chipped the paint.
Actually, you didn't even manage that.
L. 0.33/15=Oh, who cares? We know where this ends. 0 puncture.
K. 0.33/1.5=0.22. 15*0.22=3. 30/0.33=90. I'll just stop here, where the DR is presently 30 times greater than the damage. 0 concussive.
Total 0 damage. Not so much as a scratch.
D tanked it. E is much tougher than D. Not going to bother, we know how it'll end.9x19mm Parabellum, (Jacketed, from a Glock 17)
L 160, KE 50, P 0.95 (Still a tad under-powered, but it's an acceptable cost for using an accurate, reliable weapon with a large magazine. The G17 is such a weapon.)
Velocity is ~360m/s. Better penetration is mostly due to the bullet's shape and metal jacket. It also flies straighter for the same reason.
L. 0.95/0.6=1.58. (P>DD, bullet will over-penetrate with a new P of 0.35) 10/0.95=11. 160-11=149. 149 puncture damage.
KE. PF=1.58, 1.580.5
=1.26. 50/1.26=40. 40 K, leaving 10 KE.
K. 0.95/0.1=9.5. (Yes, this has to do a DD check as well.) 4/0.95=4. 40-4=36. 36 concussive damage.
Total 185 damage.
L. 0.95/1=0.95. 0.95*160=152. 10/0.95=11. 152-11=141. 141 puncture damage.
K. 0.95/0.1=9.5. 1/0.95=1. 50-1=49. 49 concussive damage.
Total 190 damage.
L. 0.95/3=0.32. 0.32*160=51. 60/0.95=63. 51-63=0. 0 puncture damage.
K. 0.95/0.3=3.2. 6/0.95=6. 50-6=44. 47 concussive damage.
Total 62 damage. (Nice dent.)
L. 0.95/15=0.06. 0.06*160=10. 150/0.95=158. Stopping here, it's 0 puncture.
K. 0.95/1.5=0.63. 0.63*50=32. 30/0.95=32. 32-32=0. 0 concussive.
Total 0 damage. (The crew is laughing at you.)
E: It's a pistol. You're shooting a tank. It does exactly what you'd expect.5.56x45mm NATO (Spitzer, boat-tailed, from an M16A4)
L 60, KE 180, P 4.5 (Well, it penetrates, but it couldn't stop a man if you had him sedated first. Alright, that's quite a bit of hyperbole, but the stopping power is terrible.)
Velocity is ~950m/s. Not the fastest projectile here, but it's more than fast enough for most purposes. Derives its penetration from its shape, which is also responsible (along with a tiny bore) for its lack of stopping power.
L. 4.5/0.6=7.5. 10/4.5=2. 60-2=58. 58 puncture.
=2.74. 180/2.74=66. 66 K, leaving 114 KE.
K. 4.5/0.1=45. 4/4.5=1. 65 concussive.
Total 123 damage.
L. 4.5/1=4.5. 10/4.5=2. 60-2=58. 58 puncture.
=2.12. 180/2.12=85. 85 K, leaving 95 KE.
K. 4.5/0.1=45. 1/4.5=0. 85 concussive.
Total 143 damage. (And yes, you get hit with 85k from this, and whatever energy you soak in from the bullet going through you. The armour actually resulted in you taking more damage. Way to go armour.)
L. 4.5/3=1.5. 60/4.5=12. 60-12=47. 47 puncture.
=1.22. 180/1.22=148. 148 K, leaving 32 KE.
K. 4.5/0.3=15. 6/4.5=1. 148-1=147. 147 concussive.
Total 194 damage. (Finally, something that inflicts noticeable damage to a vehicle, and penetrates.)
L. 4.5/15=0.3. 60*0.3=18. 300/4.5=67. 0 puncture.
K. 4.5/1.5=3. 30/4.5=7. 180-7=173. 173 concussive.
Total 173 damage. (You just left a nice, big dent. They really should have gone for the up-armour kit.)
L. Not going to bother, we know where this ends. 0 puncture.
K. 4.5/5=0.9. 0.9*180=162. 100/4.5=22. 162-22=140. 140 concussive.
Total 140 damage. (Don't think that's hurting it. It's a tank. It has tens, sometimes hundreds of thousands of hit points on each part. You'd need a torrential downpour of bullets to inflict noticeable damage.)300kj pulse laser (300mw/1ms, 1cm beam, 800nm, M3A2 laser carbine)*
X 300, K 300, P
2 (Great penetration there, and no complaints about the stopping power. Lethality is poor, due to its damage types being thermal and concussive.)
Hitscan. At least as far as it matters.
EDIT: The original "6" was incorrect. It came from one of my old notepads, in an older system. 2 is the correct value for all personal, weapons-grade lasers. (1 for toys, 2 for personal weapons, 3 for heavy AP weapons, 4 for AM weapons and 5 for AT weapons.)
X. 2/1.1=1.81. 10-20=0. 300 thermal.
K. 2/0.1=20. 4/2=2. 298 concussive.
Total 598 damage.
EDIT: There was a serious error somewhere in here. I'm not sure where it started or how it happened. Doesn't really matter now.
X. 2/0.1=20. 10-20=0. 300 thermal.
K. 2/0.1=20. 1/2=1. 299 concussive.
Total 599 damage.
X. 2/0.15=12.33. 60-20=40 260 thermal.
K. 2/0.3=6.67. 6/2=3. 300-3=297. 297 concussive.
Total 557 damage.
X. 2/0.75=2.67 300-20=280. 300-280=20. 20 thermal.
K. 2/1.5=1.33. 30/2=15. 300-15=285. 285 concussive.
Total 305 damage.
X. 2/2.5=0.8. 0.8*300=240. 1000-20=980. 240-980=0. 0 thermal.
K. 2/5=0.4. 0.4*300=120. 100/2=50. 120-50=70. 70 concussive.
Total 70 damage. (You dinged it. That's about all you accomplished.)Scorching Ray (base stats, 50% efficiency, no relevant bonuses, non-divine caster)**
X 250, K 125, P 1.25
Velocity is ~160m/s. Didn't think spells would be hitscan, did you?
X. 1.25/1.1=1.14. 10-13=0. 250 thermal.
B. 1.25/0.1=12.5. 4/1.25=3. 125-3=122. 122 concussive.
Total 372 damage.
EDIT: Something got fucked up somewhere. KDR was registering as an absurd 10 points. Fixed now.
X. 1.25/0.1=12.5. 10-13=0. 250 thermal.
K. 1.25/0.1=12.5. 1/1.25=1. 125-1=124. 124 concussive.
Total 374 damage.
X. 1.25/0.15=8.33. 60-13=47. 250-47=203. 203 thermal.
K. 1.25/0.3=4.17. 6/1.25=5. 125-5=120. 120 concussive.
Total 323 damage.
X. 1.25/0.75=1.67. 300-13=287. 250-287=0. 0 thermal.
K. 1.25/1.5=0.83. 125*0.83=104 30/1.25=24. 104-24=80. 80 concussive.
Total 80 damage.
EDIT: Once again, something was very wrong here. How did I get "133" from 150-13? Fixed now.
X. We already know how this will end. 0 thermal.
K. 1.25/2.5=0.5. 125*0.5=63. 100/1.25=80. 63-80=0. 0 concussive.
Total 0 damage. (Cast to your heart's content. The tank doesn't give.)
*From a near future setting with significant alternate history. Issued to some designated marksmen from 2018-2032, has a 10-shot power cell and a 6-second recycle time. Unreliable, slow to fire, low capacity, weighed 6kg and each power cell weighed another 1.5kg, making it possibly the least practical infantry weapon since the Chauchat. Add on low lethality rates due to its primary damage type not causing much bleed, and it's a wonder it survived long enough for better models to be produced. Still better than the previous model, which was even less reliable and held half as many shots.
**From a fantasy setting in the same universe. This spell is of Vancian preparation and usage, despite being a natural feature of the inhabitants. It uses a combination of incendiary fluid and directed infrared radiation to create a focused blast of super-heated gas. In this case, the burst of heat is ~2000k. Most casters can use spells of this grade 2-3 times each day, although they do tend to cause themselves considerable harm doing so.
Edited by Jeremy Williams, 24 August 2013 - 05:04 AM.