(If such a rule already exists in the books, let me know please because I missed it)
This arose from a discussion with a few dissatisfied players I had in my game. We are running a military campaign and they were unhappy that certain high powered weapons the enemy were using couldn't effectively threaten them from behind cover, even sometimes rather flimsy cover.
They expressed a desire, which I'd already been considering for a few weeks, for bullets to have object penetration to add more realism and an extra sense of urgency.
Now I know a bit about weapons and firearms in general but I wanted to poll some personal opinions and maybe some experience on what kind of cover would, or wouldn't, stop a specified caliber of bullet. Such as:
9mm
.45
.357
.44
5.56
7.62
.50in
12Gauge
Naturally I figure any AMR(Anti-Material Rifle) will penetrate a higher number of different kinds of materials then a lot of other weapons, whereas a 9mm pistol will likely cut through small bits of paper and your t-shirt.
The idea I was coming up with for the shoot through rules is that any bullet that bypasses an objects hardness say for example a 5.56 round overcomes an objects hardness of 10 by 12 points of damage, it would then deliver the remaining 2 points of damage to the target on the other side OR it would do half damage to the object and half damage to anything on the opposite side. So in this example the cover would sustain a point of damage, and the person using it would take a point.
This of course begs the question, what does it take to fire through people, what should I set the hardness of people at? A simple fix to this is that any target KILLED by a gunshot causes the bullet that killed him to strike something behind him, dealing any remaining damage to said object. So say a thug has 4 hitpoints left, and you really off him with a high powered shot for 28 damage. The remaining damage after killing him carries over to either a wall, desk, or someone standing FAR to close.
Of course this is the most simplistic way of dealing with shoot through rules on people, but not the most realistic. After all it means that even a high powered AMR cannot effectively shoot through a higher level opponent.
So what are your thoughts on this matter?
I'd give a human body a hardness of 2, but increase that hardness by 1 point for every point of Equipment bonus to Defence in order to take armour into account. You don't have to bring in Armour As Hardness rules, for this. It'd be a stat used only for the circumstances you mention.
Edit: I misread your post and put up a whole discussion that duplicated what you were saying, so I deleted the unnecessary bits.
The thing is though, is that a 9mm is unlikely to penetrate through an entire person, so even as a hardness of 2, the 9mm is likely to go through an opponent.
Which begs one further question, when shooting people does the bullet say do full damage to target one, then half damage to target two, and then half again that to target three until it stops piercing people?
Or does it do half damage to target one, and then half damage to target two as well?
It is a bit tricky to decide with people.
1) tell reality to bugger itself and just use damage/DR because it's simpler
2) do the research into all the different kinds of ammunition and set individual DR-piercing stats
i.e., maybe a 9mm does lots of damage but doesn't shoot through all that much, so its DRP is only 2?
Second, the simplest option for shoot-through damage is to assume that the target "absorbed" a certain amount of the damage. Therefore, if the body has 30 HPs, but the bullet does 40 HPs, then there are 10 HPs left for the next target. This is the convenient-but-not-realistic option.
The more complex/realistic option is, as you say, to assign a fractional or flat reduction for shoot-through damage; i.e., if the bullet passes through, then it carries its damage, but -10 HPs or it carries only 50% of its damage, etc.
All of that still leaves the problem of (a) determining whether the bullet passes through, and (b) whether the bullet's going in the same direction when it does pass through (bullets can do some whacky things inside a body, from what I understand).
Basically, there's a simple way to do this that's unrealistic, and a potentially vaguely realistic way of doing it that's not going to be simple. Pick your poison.
And take a .22 bullet, it will BOUNCE like crazy inside a person and come out in new and interesting direction. But that is because the bullet deflects off of a person's bones and such.
I'm likely to go with the simpler option just to keep the game flowing forward faster.
However, I was looking at a site the other day that had penetration values for 5.56 and 7.62 caliber bullets against various materials, so you might find it helpful: www.inetres.com/gp/military/infantry/rif...
You can create the odds you want by weighting the scale (10 chances of not shooting through, only one chance of shooting through clean), and you can give some ammunition a special Penetration bonus/penalty so that it will go up the scale (shoots through more often) or down the scale (stays in the body and/or changes direction). It'd be yet another roll on yet another table, so I don't know how many players are really going to go for it, but that's probably the cleanest way to do it. When a PC shoots a gun, they'd just roll an extra d20 (of an identified colour) and you check the scale. If they don't roll over a 10 (or whatever), you know that there was no shoot-through at all.
However, you'd also have to figure out whether the bullet that shoots through actually hits a target, and it's no good using the attack roll because that attack was made against a whole other target. Again, I'd say you'd want to randomise it, but that's as far as my imagination goes for one day.
And the chart and table option could be very useful. Especially if I limit them to a single die roll, and I just work out the rest of it. This prevents them from having to remember a crap-ton of rules, and allows me to make the rolls and needed adjustments for them.
Could work, could work.