"Barrier Values" of Common Items

[swaghauler]

A quick question for all the GM's out there. How do you resolve the protection value of say a sofa or desk used as cover during a fight? I posed this question during the improvised armor thread and Stainless Steel Cynic wanted a more general posting of this. Below is the system I use. Please feel free to post your house rules as well, so everyone can compare them easily (including the assignment of Armor Values to items).

I use a "Barrier Rating/Value" that spans a range from 1 to 10 and is denoted in module text by placing it in brackets like this [#]. This rating is the number of POINTS (not DICE like Armor Value) of damage the item will absorb before letting the remaining damage pass through to the target. Penetration Ratings do apply to this but that increased damage protection does have a price (for the object). The damage that's absorbed doesn't simply disappear. All of the damage the object absorbs has an effect on that object. I simply increase the wear value by one for every instance that the object absorbs damage equal to or greater than it's Barrier Rating. I also reduce the object's Barrier Rating by 1 per instance of damage penetration to represent the "erosion" of the object by the damage. I use this system for some items that are considered "armor" in the original rules. An example of this would be car doors. Most automotive bodies are easily penetrated even by handgun rounds; Therefore I apply this system to them. Below is a sample list of the Barrier Values of common items:

BV [1]: Plate Glass, Heavy Cloth barriers (drapes, padding)
BV [2]: Light Safety Coated Glass (car side windows, display windows/glass doors), Fiberglass (boats, Jeep doors), Light Furniture (rattan), 2 ply Plywood. Thin Metal (lawn shed type)
BV [3]: Interior Doors (hollow cored), Cheap Sofa/Arm Chair (pine), DOT Approved Windshield.
BV [4]: 4 ply Plywood, Interior Door (solid, soft wood), Heavily Padded Sofa/Arm Chair.
BV [5]: Exterior Door (Solid, wood & vinyl composite build), Compact/Light Car body (Toyota, Honda).
BV [6]: Hardwood Door, Hardwood Desk, Hardwood Sofa/Arm Chair. Compact Car Body/Light Car Door with electric fixtures)
BV [7]: Padded Hardwood Sofa/Arm Chair, Refrigerator, Hardwood/Steel Coated (18 gauge) Exterior Door.
BV [8]: Luxury/Heavy Car body, Filing drawer full of paper,
BV [9]: Water Tank (full),
BV [10]: Steel Security/Fire Door, Engine Block/Gen Set.

This list is just a guide for you to rate your own items in game.

So how do you deal with that guy hiding behind the sofa in game?

Swag.

[SquireNed]

Personally, as a GM I simply decide whether cover is "good" or "bad" depending on the weapon being used. It's not very realistic in some ways, but it's still quicker than dealing with it mechanically.

That M60 may not get you behind the 8" thick concrete wall, but if you're behind a standard residential wall you're toast. If someone was taking a potshot with a 9mm P handgun, maybe you'd be partially protected.

You get enough benefit from being difficult to hit that you don't really need the added boost of damage reduction to incentivize taking cover.

I remember reading something somewhere about how insurgents in Iraq/Afghanistan tended to use very suspect cover, which rarely worked out well for them.

[Olefin]

Actually it may be more important when you are dealing with grenades and explosives

ever see the mythbusters episode where they showed the effects of diving behind simple objects when a bomb is about to go off? surprising what you can hide behind and survive the blast

also depends what the enemy is using for a weapon - its one thing to take cover from a civilian shotgun or .38, a highly different thing (as pointed out by Ned) when its a military machine gun

[CDAT]

Originally Posted by swaghauler

A quick question for all the GM's out there. How do you resolve the protection value of say a sofa or desk used as cover during a fight? I posed this question during the improvised armor thread and Stainless Steel Cynic wanted a more general posting of this. Below is the system I use. Please feel free to post your house rules as well, so everyone can compare them easily (including the assignment of Armor Values to items).

I use a "Barrier Rating/Value" that spans a range from 1 to 10 and is denoted in module text by placing it in brackets like this [#]. This rating is the number of POINTS (not DICE like Armor Value) of damage the item will absorb before letting the remaining damage pass through to the target. Penetration Ratings do apply to this but that increased damage protection does have a price (for the object). The damage that's absorbed doesn't simply disappear. All of the damage the object absorbs has an effect on that object. I simply increase the wear value by one for every instance that the object absorbs damage equal to or greater than it's Barrier Rating. I also reduce the object's Barrier Rating by 1 per instance of damage penetration to represent the "erosion" of the object by the damage. I use this system for some items that are considered "armor" in the original rules. An example of this would be car doors. Most automotive bodies are easily penetrated even by handgun rounds; Therefore I apply this system to them. Below is a sample list of the Barrier Values of common items:

BV [1]: Plate Glass, Heavy Cloth barriers (drapes, padding)
BV [2]: Light Safety Coated Glass (car side windows, display windows/glass doors), Fiberglass (boats, Jeep doors), Light Furniture (rattan), 2 ply Plywood. Thin Metal (lawn shed type)
BV [3]: Interior Doors (hollow cored), Cheap Sofa/Arm Chair (pine), DOT Approved Windshield.
BV [4]: 4 ply Plywood, Interior Door (solid, soft wood), Heavily Padded Sofa/Arm Chair.
BV [5]: Exterior Door (Solid, wood & vinyl composite build), Compact/Light Car body (Toyota, Honda).
BV [6]: Hardwood Door, Hardwood Desk, Hardwood Sofa/Arm Chair. Compact Car Body/Light Car Door with electric fixtures)
BV [7]: Padded Hardwood Sofa/Arm Chair, Refrigerator, Hardwood/Steel Coated (18 gauge) Exterior Door.
BV [8]: Luxury/Heavy Car body, Filing drawer full of paper,
BV [9]: Water Tank (full),
BV [10]: Steel Security/Fire Door, Engine Block/Gen Set.

This list is just a guide for you to rate your own items in game.

So how do you deal with that guy hiding behind the sofa in game?

Swag.

Having been part of the group that tested rounds against different objects with my last agency as we were going to a new sidearm/rifles. My experience is that plate glass and the side windows of a car reacted the same to bullets with one exception that being the size of the pieces of glass, we did not test anything small enough to not destroy it in one round. If anything plate glass is stronger as I have seen it get hit with BB guns and not break, but have seen side windows hit with BB guns and every time I have see it they always broke. As for the front windshield it is interesting, I have seen where it had almost no impact to the bullet, and other times were the bullet was almost destroyed going through the windshield. The biggest thing that I have seen is that almost with out fail it changed the direction of flight of the bullet, often enough to miss the target.

I am not sure what you mean with Compact/Light Car body, Luxury Heavy Car Body? We shot a bunch of cars and even more doors from all sorts of makes and models, most with electronic controls. The biggest factor was the speed and mass of the round. The 12G slug was the best for this, followed by pistols the larger the better, rifle was next again larger better than smaller, and the worst as in did not penetrate the door was the 12G 00 shot.

As for most of the cloth materials they did not make any real difference, besides they made most of the bullets in to effetely FMJ as it filled the hollow point and they did not expand as well as they would have otherwise. A lot of the other items Fiberglass, 2 ply Plywood, hollow cored door, and thin metal I would say could be concealment but if you get shot behind one you would not know the difference. The different woods I would say that the amount it is going through is the biggest issue and it is more than one inch of hard wood stops 1 point, two inches stop 2 points, and three inches stop 3 points and so on, it would be more one inch stops 1 point, two inches stop 2 points, but three inches stop 6 points and it keeps growing, I am just guessing here but would say between four and six inches would stop most pistol rounds, and around eight inches or so would stop most rifles rounds (.308/.30-06 and lower) about a foot or so for .50BMG ball, AP would up the numbers same as adding some heavy gauge metal on the wood.

As for the rest of the items I have no experience with shooting house hold appliances, did not come up in our testing, so your guess is as good or maybe better than mine. I would treat the filling cabinet as equal to about the same size of light wood, yes paper is not very tough, but packed together in a cabinet it adds up really quick and can stop a lot of bullets cold. Water is one of the best bullet stoppers out there, it just issues in that it is a liquid, so it will leave any hole that it can get out of so it degrades much faster than others. The engine block will stop most rifle rounds, I have not seen it tested with anything larger then .30-06 but have been told it will stop a .50BMG with ball at least. And last Steel security doors there is several levels to these the one we have at work will stop .50 Slap round, and most explosives they weigh in at over 250lbs each and are about four inches thick, and go up from there the largest we have is 15 tons and a foot and half thick. So anything short of a tank round will not get through it.

Just my thought, for the most part I like your idea, just would change some of the values and make water lose more per hit.

[.45cultist]

Originally Posted by CDAT

Having been part of the group that tested rounds against different objects with my last agency as we were going to a new sidearm/rifles. My experience is that plate glass and the side windows of a car reacted the same to bullets with one exception that being the size of the pieces of glass, we did not test anything small enough to not destroy it in one round. If anything plate glass is stronger as I have seen it get hit with BB guns and not break, but have seen side windows hit with BB guns and every time I have see it they always broke. As for the front windshield it is interesting, I have seen where it had almost no impact to the bullet, and other times were the bullet was almost destroyed going through the windshield. The biggest thing that I have seen is that almost with out fail it changed the direction of flight of the bullet, often enough to miss the target.

I am not sure what you mean with Compact/Light Car body, Luxury Heavy Car Body? We shot a bunch of cars and even more doors from all sorts of makes and models, most with electronic controls. The biggest factor was the speed and mass of the round. The 12G slug was the best for this, followed by pistols the larger the better, rifle was next again larger better than smaller, and the worst as in did not penetrate the door was the 12G 00 shot.

As for most of the cloth materials they did not make any real difference, besides they made most of the bullets in to effetely FMJ as it filled the hollow point and they did not expand as well as they would have otherwise. A lot of the other items Fiberglass, 2 ply Plywood, hollow cored door, and thin metal I would say could be concealment but if you get shot behind one you would not know the difference. The different woods I would say that the amount it is going through is the biggest issue and it is more than one inch of hard wood stops 1 point, two inches stop 2 points, and three inches stop 3 points and so on, it would be more one inch stops 1 point, two inches stop 2 points, but three inches stop 6 points and it keeps growing, I am just guessing here but would say between four and six inches would stop most pistol rounds, and around eight inches or so would stop most rifles rounds (.308/.30-06 and lower) about a foot or so for .50BMG ball, AP would up the numbers same as adding some heavy gauge metal on the wood.

As for the rest of the items I have no experience with shooting house hold appliances, did not come up in our testing, so your guess is as good or maybe better than mine. I would treat the filling cabinet as equal to about the same size of light wood, yes paper is not very tough, but packed together in a cabinet it adds up really quick and can stop a lot of bullets cold. Water is one of the best bullet stoppers out there, it just issues in that it is a liquid, so it will leave any hole that it can get out of so it degrades much faster than others. The engine block will stop most rifle rounds, I have not seen it tested with anything larger then .30-06 but have been told it will stop a .50BMG with ball at least. And last Steel security doors there is several levels to these the one we have at work will stop .50 Slap round, and most explosives they weigh in at over 250lbs each and are about four inches thick, and go up from there the largest we have is 15 tons and a foot and half thick. So anything short of a tank round will not get through it.

Just my thought, for the most part I like your idea, just would change some of the values and make water lose more per hit.

When he was younger, my Brother in-Law picked up a teen suspect that had a spark plug on a shoe string. A more senior officer explained it is used to bust car windows and plate glass due to the ceramic body.

[swaghauler]

I was kind of in a hurry when I posted this so here's a little clarification on my list.
The first clarification is that I use 1d10 for damage not 1d6. Twilight's damage for weapons is somewhat understated. My list is based on the fact that you can roll up to 10 damage points on a single roll. I have been considering using 1d6 for pistols and 1d10 for rifles to better differentiate the range of damage between the two. This is because a pistol's damage tends to be more consistent (as far as terminal ballistics can be); whereas a rifle's effect can vary from just "punching through" doing very little damage, or tumbling there by causing massive damage to the target. I just haven't decided to do it yet.

A better gauge for sheet metal/car bodies would be to use the gauge of metal used in the automobile's body. This would be:
-20 gauge to 18 gauge body panels with very little padding inside would be the equivalent of subcompact or compact car bodies.
-16 gauge to 14 gauge body panels with moderate padding and/or electric drive motors would be equal to a compact or light car that was built to a higher standard of luxury. This would also be the standard for most 70's era automobiles.
-12 gauge to 1/8" of mild steel would be the level of construction of certain luxury cars as well as most cars from the 50's and 60's.
for those who don't know this; The higher the gauge, the thinner the steel in that panel.

The plate glass verses safety glass is the difference between the laminated glass used in most commercial glass today and the older glass (that will shatter and cut you) used in older display cases or buildings. Under my rules, the older glass is destroyed after the first hit. Safety glass can withstand at least one hit before shattering. You can find photos everywhere which will show a single bullet hole in a side window that's completely "spider-webbed" but still in the door frame.

The cloth entry is not the type of drape that you would hang; but rather the heavy tapestries found in castles or the throw rugs/carpeting (complete with backing) that people in public housing hang over their windows (often called "ghetto drapes" where I live).

The steel fire door is not the reinforced doors your referring to, but the solid core door with 12 gauge mild steel on either side often used to meet "fire resistance" requirements in public buildings. It is found in stairwells, between hospital wards, and the exterior of schools. It's "security function" is secondary to the fire barrier role.

I have had the privilege of shooting up a fully furnished trailer on the testing range. The only objects in that structure which provided certain protection from small arms were the refrigerator (with containers of food), the hot water tank (filled), and the toilet (porcelain). The water tank was holed 6 times and still took a few minutes to empty out onto the floor. I have also shot a ten foot diameter 800 gallon? (I can't remember now) plastic tank full of holes so we could use it as a "drainage strainer" (buried in the ground with "rip wrap" cloth inside it to catch debris washing towards a local creek) for my buddy's farm. It took nearly 10 minutes for it to drain with more than a hundred .30 caliber holes in it. Any kind of liquid storage tank provides very good protection as long as its contents are not explosive, flammable, corrosive, or toxic.

Don't get hung up on how thick the object or material is, but rather how well it is constructed (or reinforced). You could easily rate a rusty Fire Door downwards due to its condition.

The concept behind this rule is to give you an idea how much you can reduce the damage of a hit for intervening objects. I generally use it "off the cuff" and often ignore things like the Penetration multiplier noted above, UNLESS I feel the players need the break or to advance the story. I still remember the session when the rebels attempted to assassinate my players as they met with a prominent smuggler in Mombasa. They were exchanging fire with two rebels (who were hiding on either side of the office doorway) while hiding behind a large heavily padded leather Victorian style sofa as the smuggler screamed "You B*****ds! That's my grandmother's 100 year old sofa!"

[Slappy]

Great thoughts here.

One potential addition is that for complex items, you may need to roll for the value. Sometimes for a couch you hit fabric, which has no stopping power. Sometimes, you hit the 100 year old solid wood frame which would help a bit. Maybe 50/50 for the value.

[pmulcahy11b]

I guess my house, with largely sheetrock interior walls, would just be so much fodder...

[LT. Ox]

Originally Posted by pmulcahy11b

I guess my house, with largely sheetrock interior walls, would just be so much fodder...

I carried my Browning auto loader with Number four buck shot rather than double 0, it also was chambered for three inch instead of two and three-quarter.
I twice had a perp-(bad guy) shoot at me then "hide" behind a normal 2x4 wall, the result was nasty after one round from the twelve.
I fired at about eighteen inches above the floor and a foot from the door way. The two separate incidents did not result in fatalities but did require immediate and serious medical attention.
The first individual was standing in a slight crouch, both legs were badly damaged. The second had dropped to one knee and faired much worse.