Advance Rules for Cover and Concealment

[Darthmoe]

Before I begin I would like to repeat a quote that was said in the Vehicle Combat Rules

Two things:

1) I like to make a firm distinction between "complicated" and "complex". The former is needlessly muddled, the latter can be detailed, but also implies an elegance that indicates an underlying simplicity. Aiming for the latter is what we're after.

2) I think, so long as we make a distinction between "Basic" and "Advanced" rules, there should be no argument over complexity of combat, be it vehicular or otherwise. Me, I'd be more likely to run a game using the basic rules, because that's the level of player I'm dealing with right now. But I'd still like to know that the system can DO something more realistic/complex, in case I ever want to explore that. I think there's room for both.

Okay that had to be done first because if I failed to state that clearly from the get go I would have my thread clogged with "that's too complicated" posts. These rules are probably not for the casual gamer they are more for players who want high performance RL combat simulators. These rules are inspired by my RL Law Enforcement training. These are for players who like a level of complexity with out having a bunch of complicated tables to follow. Implementing these makes combat a lot more dynamic and tactical in nature.

NOTES
Using advance cover rules will change the way combat works in some significant ways. Because combat because combat now revolves around cover a whole lot more than it does in the standard game. These are two things that you should definitely take note of.

Talents / Feats that defeat cover
The have been a lot of these over the years examples include skip fire in d20 Modern, sniper in SWSE, point blank shot in 4.0, and even the aiming mechanic in SWSE. General rule of thumb is if you use these rules things that give you the ability to ignore cover should be done away with or at the very least nerfed.
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Armor
The game that I invented these rules for actually took place in the 1930s so armor was extremely limited in both quality and quantity. In more modern settings armor is a primary form of defense, in these rules cover becomes a primary form of defense as well. It would probably work okay to have armor and advance cover rules going in the same game but it will make combat last longer, because characters will be harder to hit. For this reason if these rules are used you might want to consider doing a simple nerf of armor, but having said that I am waiting to see how armor actually works before telling you how to do so.

Destroying Cover
If you use these rules most examples of covers would not be so easy to destroy. An AK-47 for example could blast multiple holes in a door, but really wouldn't destroy the door.

MECHANICS
Okay we got those items out of the way it's time to the mechanics of it all.

Concealment
To be clear on this fact servile editions of D&D including 4.0, they erroneously refer to concealment as soft cover. There is a very clear distinction between soft cover and concealment. With concealment there is nothing physical between you and the bullet (or arrow, laser, blaster bolt, phaser beam, death ray, or whatever). Examples of concealment include smoke, shadows and darkness, tall grass and shrubbery, curtains and closed blinds, mist or fog. Sometimes you have to think a bit abstractly about concealment as well. For example in a dark environment pretty much everyone who isn't wearing a glow in the dark clothing is going to have concealment, but creatures low light vision (either through a species trait or though night vision goggles or similar equipment) will be able to ignore all but the most extreme forms of darkness. However if were shine an extremely bright light into the eyes of a defending creature then you are going to have concealment against the defender even if the defender has low light vision. Additionally the defender won't have a concealment against you because you have him lit up like a Christmas tree. Rules wise I can think of no conceivable reason not to use Gary's rules for concealment it gives a +2 bonus and does not prevent attacks of opportunity.

Cover
Unlike concealment with cover you have an actual physical barrier between you and the projectile. In some cases the barrier may not stop the projectile, but it will always slow it down and reduce the damage. There are three levels of cover, poor cover which only covers half of your body or less gives a defense bonus of +2, good cover covers more than half of you body and gives you a defense bonus of +5, excellent cover is extremely rare but only leaves a tiny portion of your body open to gun fire (examples include an arrow slot, or the door slots in an armored car) and gives you a +10 bonus. Unlike concealment it protects you from attacks of opportunity. There are also two types of cover to be concerned about.

Soft Cover
Soft cover is not strong or thick enough to stop a bullet a 100% of the time but it offers protection to defender none the less and is a significant step above concealment. When confronted with soft cover a shooter has two options. He can choose to shoot around the soft cover in which case the cover acts normally. Alternatively he may choose to shoot thorough the cover in which case he treats the cover as concealment, if he hits the defender his damage is reduced by the hardness of the defenders cover, and any excess damage is then transferred to the defender. It's worth noting that while multiple layers of soft cover would not improve the defender's cover defense bonus they would improve the damage reduction of the defender. It's also worth noting that it's usually only practical to shoot through soft cover if the defender has at least good cover. Examples of soft of cover.

*Thick glass, turned over bed mattress, multiple layers of cardboard = DR 1
*Thin wood (example hollow core door or garden fence) dry wall, plaster, sheet rock, = DR 3
* Thick wood, car door = DR 5
* Brick walls, stone walls, thin layer of steel = DR 10

Hard Cover
Hard Cover is too strong for a bullet to penetrate through. Examples of hard cover.

* Tree trunk
* The engine block of a car
* Thick steel plating
* Bullet proof glass
* Concrete monuments
* Standing water
* Sand dunes
* sand bags

[JaredGaume]

I am suprised no one has commented on this.
Two words from me:

I like!

[Crofter]

I like these rules, too. Especially how the cover gives DR instead of affecting hit rolls.

I'd like, however, make a small notion. When doing my military service, we were told to shoot through trees; so I think you can shoot through tree trunks, at least with Finnish assault rifles (most likely with other rifles, too). I don't mind them being impenetrable under the rules, I just found it curious.

[JaredGaume]

Maybe it depends on the tree

[Darthmoe]

WOW!!! People like my rules!!! You guys are two of the first to like it. The only other guy who did was also a cop as well. One thing I will say is I didn't read Gary's rules in e20 Lite closely enough and somehow I missed the element about leaning into cover. That's a fun rule to play with and actually it increases the capabilities of my system greatly.

For example imagine you standing behind a rock that is about as tall as knees. Ordinary that rock offers you no protective cover at all, but it would be reasonable to "lean into" or in this case kneel or crouch behind it and gain a +2 cover bonus.

If such a system were combined with my current rules we might see a cover bonus listing like this. Note the improved cover bonus for leaning into cover are included in parenthesis "( )". Also for lack of a better improvised cover will refer to my example above about crouching behind a knee high rock.

Improvised Cover = +0 (+2)
Poor Cover = +2 (+5)
Good Cover = +5 (+10)
Improved Cover = +10 (full cover)

Those rules would make for an extremely tactical game, and the functionality of armor would almost certainly have to be changed if this system were used. Either armor could give a small DR or else the defense bonuses would just have to be nerfed.

Alternatively we could take the simpler approach which still gives some fairly advanced rules, and just use Gary's rules for cover and simply add in my rules for shooting through cover, and possibly my rules for improvised cover as well. If this were done this is the kind of cover bonuses we would see.

Improvised Cover = +0 (+2)
Normal Cover = +2 (+5)
Improved Cover = +5 (full cover)

[Darthmoe]

I like these rules, too. Especially how the cover gives DR instead of affecting hit rolls.

I'd like, however, make a small notion. When doing my military service, we were told to shoot through trees; so I think you can shoot through tree trunks, at least with Finnish assault rifles (most likely with other rifles, too). I don't mind them being impenetrable under the rules, I just found it curious.

Technically under my rules soft cover still does give a defense bonus when you shoot through, but the bonus is treated as if the cover were concealment and not cover. Concealment isn't so great in rules, but it was originally a bit less useful, because I used to have two levels of concealment as well poor concealment (+1) and good concealment (+2). I standardized poor and good concealment just to propose a system because I thought it might make it simpler even though I myself would prefer the two layers of concealment as well.

I agree with you that rifles would shoot through at least some if not most trees, as well as a few other objects that I have listed as impenetrable (clearly there are some rifles that can get through heavy steel plating, or bullet proof glass of course there again it depends the thickness of the object in question). It all came down to the simple fact that I had to the draw line somewhere.

My thinking on the matter was also this. I wanted rules that would allow you to shoot through cover, but wouldn't be overly complicated, and that wouldn't be so complicated, or so powerful that they broke the game when used. With that in mind I went just about conservatively as a could, knowing the whole time that the fact you would be able to shoot through cover at all was a pretty radical change from previous games. I figured that the first generation of rules would be good, but also imperfect, but at the same time all of the players who were thinking "hey these rules for shooting through cover could be better" would also just be pleased that they even have rules for shooting through cover. In the long run if this idea made it into the book at all it would get people thinking about and many variant house rules would pop up. We would then be able to take those house rules and design a better 2nd generation of advance cover rules. But since this is the first generation rules, and the fact that we are in completely uncharted territory with this I'm not expecting perfection of the first go around.

[Inquisitor Tremayne]

I like what you have but I prefer Saga's use of Concealment in that if you attack a target with Concealment you take a -2 to the attack roll. I don't really see how concealment would increase your defenses, but I can see how it would be difficult to shoot at someone that is concealed.

Likewise you cannot attack a target with Total Concealment but may make attacks where you think that target is at a -5 (which I think should be a -10).

[Darthmoe]

I like what you have but I prefer Saga's use of Concealment in that if you attack a target with Concealment you take a -2 to the attack roll. I don't really see how concealment would increase your defenses, but I can see how it would be difficult to shoot at someone that is concealed.

Likewise you cannot attack a target with Total Concealment but may make attacks where you think that target is at a -5 (which I think should be a -10).

Yeah minor details with the numbers, but I will admit you have me with semantics. Concealment only helps you somewhat because as long as a portion of the defender's body is visible it is pretty easy it's pretty easy to guessamate where the rest of his body is, unless of course he is completely obscured from view, as you pointed, but unless the defender is behind some kind of wall he won't have total concealment. The easy way to handle what kind of attack penalty should be same penalty as if the attacker were blind. Note I think that is pretty much how they handle it now anyway.

[Inquisitor Tremayne]

Yeah minor details with the numbers, but I will admit you have me with semantics. Concealment only helps you somewhat because as long as a portion of the defender's body is visible it is pretty easy it's pretty easy to guessamate where the rest of his body is, unless of course he is completely obscured from view, as you pointed, but unless the defender is behind some kind of wall he won't have total concealment. The easy way to handle what kind of attack penalty should be same penalty as if the attacker were blind. Note I think that is pretty much how they handle it now anyway.

Actually Total Concealment is defined as having line of effect but not line of sight, in Saga.

So Total Concealment would not be something you benefit from having Total Cover. Two completely different states. Total Cover means you have neither line of sight nor line of effect, meaning you can't even attempt to make an attack against the target. So being completely behind a wall = Total Cover, being in a really think fog = Total Concealment, being in an area of tall grass or poor lighting = Concealment.

At least, as defined by SW Saga.

Sorry, I AM a stickler for definitions, semantics.

[Darthmoe]

Yeah minor details with the numbers, but I will admit you have me with semantics. Concealment only helps you somewhat because as long as a portion of the defender's body is visible it is pretty easy it's pretty easy to guessamate where the rest of his body is, unless of course he is completely obscured from view, as you pointed, but unless the defender is behind some kind of wall he won't have total concealment. The easy way to handle what kind of attack penalty should be same penalty as if the attacker were blind. Note I think that is pretty much how they handle it now anyway.

Actually Total Concealment is defined as having line of effect but not line of sight, in Saga.

So Total Concealment would not be something you benefit from having Total Cover. Two completely different states. Total Cover means you have neither line of sight nor line of effect, meaning you can't even attempt to make an attack against the target. So being completely behind a wall = Total Cover, being in a really think fog = Total Concealment, being in an area of tall grass or poor lighting = Concealment.

At least, as defined by SW Saga.

Sorry, I AM a stickler for definitions, semantics.

Well the old definitions have to be subjected to reinterpretation under these rules. For one thing having cover almost always grants concealment as well. I say almost always because bullet proof is an example of cover that one can clearly see through but not shoot though. Concealment really means some kind of visual obstacle that would hinder a shooter's ability to aim, and therefore cause him to miss his shot when he might otherwise would have hit.

Soft Cover is another term that must be redefined, and it's a bit of a wild card term whose definition changes from game to game. In D&D 4.0 and some older editions of D&D as well soft cover is just another name for concealment. In SAGA soft cover refers to using another character as cover, the classic example being a hostage situation. In my rules I used the correct police and military definition for soft cover which is basically means a solid form of concealment. Rules wise soft cover is basically concealment in which you get a damage reduction in addition to obscuring the vision of the opposing shooter and thus causing him to have an attack penalty. Of course the idea of soft cover being a form of solid concealment is accurate in the overwhelming majority of instances, it's ccorrect a 100% of the time. For instance glass panels are a form of soft cover that most people don't think about. Obviously you have a clear and unobstructed view of the defenders behind the glass, but that glass still offers a physical barrier that the layman would probably not take into account. Any time a bullet strikes a solid object it has an effect on it's trajectory, so shooting through glass would actually have to effects on the bullet. First of all the glass would deflect the bullet somewhat which just might be enough to cause a miss, and second of all the trauma of the bullet smashing through the glass will cause it to lose some of it's velocity which would also help to make the shoot less accurate in addition to reducing damage. There have actually been a number of cases where police snipers have fired through glass, and missed their shots because of the glass barriers.

Hard Cover is a new term and it basically what cover always has been in d20. I will admit that the distinction between hard and soft cover is a bit arbitrary at the moment, basically I'm just picking out the toughest examples of cover that I can think of and saying that those are impenetrable. Maybe it isn't a 100% 'realistic' but it's a heck of a lot more 'realistic' than the previous rules, and at the same time it benefits both sides to just declare some forms of cover as 'safe'.

Another issue I did not originally, but it is related to Crofter's comment is that in my ordinal rules some weapons were described as armor piercing and they reduced the damage reduction of soft cover by half (rounded down of course). In the 1930s which my game originally took place in it was easy to define those weapons because a small handful of handguns had a legendary reputation for cutting through armor and cover, the rest didn't, then of course you had rifles. In more modern times I think it's relatively to define such weapons. The 9mm is right on the cusp so it could go either way, but any 9mm magnum or 9mm with a longer case length are clearly easily penetrate through soft cover. Likewise the .38 super and .357 sig would easily penetrate soft cover as well as any pistol that fires a rifle cartridge (other than the .22 long rifle), or any pistol described as a magnum. When it comes to rifles any rifle (including assault rifles), other than the .22 long rifle would easily defeat soft cover as well. Body armor is more effective in the modern era though so these ammo types wouldn't necessary penetrate an armored vest even though they might be effective against soft cover.

[Inquisitor Tremayne]

For the record I wasn't knocking your rules, I actually really like them. I just wanted to present some clearer definitions of the terms because as I read it, it seems the terms were/are getting mixed.

For one thing having cover almost always grants concealment as well. I say almost always because bullet proof is an example of cover that one can clearly see through but not shoot though. Concealment really means some kind of visual obstacle that would hinder a shooter's ability to aim, and therefore cause him to miss his shot when he might otherwise would have hit.

You will have to present some other ways to convince me of this because bullet proof is only one way and far from being close to "almost always".

Unless you are proposing that someone with cover, therefore has concealment as well because the attacker is visually impaired?

Let's use the bullet-proof glass as an example. Two people stand on either side of bp glass and shoot at each other, since bp glass is considered soft cover DR comes into effect. But since the characters can see each other but do not have line of effect due to the barrier of the bp glass they only get cover.

They would NOT have concealment from each other if what you previously wrote holds true:

There is a very clear distinction between soft cover and concealment. With concealment there is nothing physical between you and the bullet (or arrow, laser, blaster bolt, phaser beam, death ray, or whatever). Examples of concealment include smoke, shadows and darkness, tall grass and shrubbery, curtains and closed blinds, mist or fog.

Is that correct?

Because from this statement:

Concealment really means some kind of visual obstacle that would hinder a shooter's ability to aim, and therefore cause him to miss his shot when he might otherwise would have hit.

you seem to imply that bp glass WOULD offer concealment.



Yep! You guessed it, rules lawyer right here!

[Darthmoe]

Scenario of how cover also offers you concealment

Let's you are taking cover behind an M1A1 Abrams tank. Now that Abrams tank has both the qualities of cover and concealment and you gain the benefits of which ever one would be most beneficial which 99.9% of time would be cover. Cover is better than concealment in my system for two reasons. It gives you a better defense (okay technically it gives the other guy an attack penalty but no need to split hairs here), and according to the e20 lite rules cover also prevents attack of opportunity as well. Under ordinary circumstances that tank will project you as basically an extension of worn body armor. It's completely bullet proof and the AR-15s of the bad guys your fighting with have no chance of dealing any real damage to that tank. The concealment of the tank is irrelevant because you gain a better level of protection from it's cover value, and the is exactly a 0% chance of bullet passing through the tank's armor anyway. You may still get shot of course, but the bad guys will have to try and shoot around the tank and not through it.

Now let's change the situation a bit and say that the bad guys have and hand held railgun. For the sack of argument and this example lets also say that railgun ignores all object hardness, character damage reduction, armor defense bonus, and cover bonuses. Basically it can shoot through anything with ease. So now the question is does that Abrams tank offer you any protective value at all right? The answer to that is yes it does, it still acts as concealment. Technically that Abrams tank now gives what is pretty much the same level of protection you would get from hiding behind a thin sheet of plywood, or even a cloth curtain (assuming the tank does not blow up of course).

Now let's go back to the example of the bullet proof glass panel, and for the sack of argument let's say that this time the BP glass is an three inches thick and made from the highest quality materials available. This panel is see through so it gives you cover, but not concealment. The fact you don't have concealment really does not matter if your opponent is armed with a 9mm Glock. He can fire dozens of rounds into the bullet proof glass panel but he's not going to get through. But, if you're friend with the railgun comes back, that bullet proof glass which was completely impenetrable against the 9mm is going to be completely useless against the unstoppable railgun, you'd be better off hiding behind a curtain. Now if the BP glass were tinted or mirrored that would at least be something, that would be concealment.

Basically glass (be it bulletproof glass or ordinary glass) is one of the only examples I can think of in which cover wouldn't also give you concealment. The only other example is if your hiding underneath water, but even then the water could give you concealment if it's murky enough. But, with the exception of these two notable examples concealment is a lesser included value of cover.

Edit

Also I'm glad to have the support of a rules lawyer it makes it easier to ensure balance that way.

[Darthmoe]

A few extra notes about cover just encase somebody hasn't gotten tired of my talking yet. First and foremost I think that advance cover rules should sync up with ordinary cover rules because I want the ability to do things like shooting through cover to be optional for three very important reasons.

1. Casual gamers and Newbes - Quite simply this group of gamers probably isn't very interested in a highly tactical game so we shouldn't force it on them.

2. Setting - Sometimes the ability to shoot through cover just isn't suitable for all campaigns, for the same reasons that having the magical ability to shoot around (ex. skip fire) isn't suitable for all campaigns either. Maybe the GM wants to run a spaghetti western where an over turned table is an impenetrable bullet proof shield.

3. Progress Eras - Shooting through cover is more a less a theme of the modern firearms era. It's not so appropriate for the era of black powder muskets though still technically possible if the GM wants to allow it (I'd probably double the DR of all forms of soft cover). For that matter it's equally inappropriate for many futuristic eras as well. Star Wars, blaster bolts explode on contact for example, and for whatever reason Star Trek phaser beams do not seem capable of penetrating cover either.

That being said I particularly like Gary's for cover and I feel that my rules easily fit with his to make the ultimate tactical game. The two things I like the best about Gary's rules is that there is a clear distinction between concealment and cover because cover stops attacks of opportunity where as concealment does not. But that being said in order for that difference to have real meaning you need to be able to threaten attacks of opportunity with firearms as well (at least under some limited conditions).

The thing I like the best about his cover system is the ability to lean into cover to enhance the value of cover that you receive. If I had one thing to change about it, it would be increasing the degrees of cover one could have. The way I would fix that is by implementing my idea for poor or improvised cover. An example of poor cover would be my example of the knee high rock, too small to offer you protection under normal circumstances, but if you actively seek cover behind it (lean into it) then it could give you a +2 cover bonus.

Another option I would like to see in addition to leaning into cover is ducking behind cover. Ducking behind cover would be a completely defensive maneuver, that prevents you from being able to attack, but improves the value of you cover by 2 degrees.

Here is an example of this could work. The numbers outside of the parenthesis and brackets is the regular value of cover. That's the bonus you would get if you just happen to be standing behind cover, but not actively seeking cover behind the said object. The number in parenthesis ( ) is the cover bonus you would get if you were actively seeking cover behind the said the object ie leaning into your cover. The numbers in brackets [ ] is the value for ducking behind cover. When you are ducking behind cover you are trying to make yourself as small as possible with out any thought of fighting back. You might do this if you were expecting an explosive or area attack to come your way.

Poor Cover = +0, (+2), [+5]
Good Cover = +2, (+5), [+10]
Improved Cover = +5, (+10), [full cover]

Note I changed Gary's rules for leaning into improved cover, but I think this more accurately depicts the feel Gary may have been going for. Also I suppose it may be possible to blindly fire over the top of your head or around the corner while you are ducking behind your cover. Your shots wouldn't amount to anything more than spray and prey of course, but you would be protected. It's not likely something you would do behind improved cover though, because there would be basically no incentive. Your defense would not be improved (as you certainly would not have full cover if your hand(s) are exposed), and you would be taking some major penalties to your attacks as well.

[Darthmoe]

Well for those of you who are following this there is some exciting news on this front. These rules actually made it into version 2!!! Well not exactly these rule Gary expanded on them, and I think that we made a pretty good team on this.

One question I do have is what about stacking multiple layers of cover. The reason why I ask is that on one hand the version 2 rules for cover are awesome!!! But, know that one hangup other gamers will have with it, is that Gary made it so that if you strike the cover instead of the defender you automatically have a chance of shooting through the defender's cover and injuring him anyway. I am cool with that actually, because I admit it's the way it should be, and that was in fact my original idea. The problem is that it now somewhat invalidates the benefits of cover, though on the other hand there are no longer any techniques to easily defeat by ignoring (such as ricochet shot in d20 modern, point blank shot in 4.0, or the aiming mechanic in SAGA) so in that regard cover is more beneficial, even at high levels. Still I think it's beneficial and realistic to stack the hardness values from multiple objects of cover.

I also wanted to inquire about another classic example of cover that we somehow over looked. We have the hardness for an barrel, but what about a full barrel? Somehow a hardness of 20 seems about right.

[Darthmoe]

Okay I took a long hard look at the cover and concealment and how they interact and this is what I think happens.

Concealment does not give you a bonus to defense it all it instead gives your enemy a penalty to hit. A simple distinction but it matters, especially in cases where you have things like darkness combined with spotlights, and in instances where the defender has both concealment and cover at the same time (which is almost any time the defender has cover).

Cover does not give you a bonus to defense either, instead it simply means your opponent is going to have beat your primary defense score by a certain number of degrees in order to avoid having his damage roll nerfed.

Here's the thing when you have cover you also have a like level of concealment. An example a detective McCall is taking cover behind his unmarked squad-car, he has both normal concealment and cover against his opponent Bad Guy Billy. McCall has a primary defense of 17, Billy rolls a 19 on his attack roll. Billy's attack roll is reduced by 2 because of the concealment offered by McCall's squad-car (19 -2 = an attack roll of 17). Billy hits McCall, but Billy also has to beat McCall's primary defense by 2 degrees/points in order to bypass the hardness granted by McCall's cover. Billy does not roll high enough (after you account for McCall's concealment) and so Billy's damage is reduced. Billy is using armor piercing rounds (penetrating 5) the GM rules that McCall has two layers of thin steel in front of him, plus the engine block of the car which the GM rules gives McCall an additional 10 points of hardness. The total hardness offered by car is 20 (5 for each side wall of the car, and 10 for the engine block). Billy rolls a damage of 16 against McCall's hardness of 20. The armor piercing rounds in Billy's gun reduce the effective hardness of McCall's cover by 5 effectively giving him a a hardness of 15. 16 damage - 15 hardness = 1 point of damage for McCall.

This is the way that cover was intended to work, but there might be a bit of an issue with stacking Hardness values together. This is the way the rules were intended to work, but I am not sure how far we want to take the advantage offered by cover. My gut instinct is that anyone using this high level cover/concealment should also be playing with "don't get shot rules ie high lethality games", we might want a cover system that can scale down a bit for high heroic games. It seems counter intuitive but if PCs can already survive a high amount of punishment to begin with, throwing in cover/concealment rules like this will probably make combat last forever, as bad as 4.0 if not worse. No matter what tactical movement will become far more important in e20 than in any other d20 game before it, because with cover rules that are this strong you will need to out flank your opponents.

[Darthmoe]

Alright I've been doing a bit of thinking on this and I came up with three different ways of stacking cover hardness values.

The first and most obvious and the method I would recommend for high heroic games is to simply take the highest hardness value and only apply that. In my example of McCall vs. Badguy Billy only the engine block would count.

The second method which I am still working on would involve the strongest barrier adding full hardness and all secondary barriers would give a bonus but would not add the full amount. One idea is that secondary barriers would add hardness as if they were one or two levels or lower. So if we go back to the example of the detective taking cover behind his car the engine block would give him the full 10 points of hardness. The side panels of the car are secondary barriers so they would be treated as one level lower and that would give them a hardness bonus of +2 each. The detective would then have a total hardness of 14 that would be given to him by all of barrier levels.

The last and most advance method is stack all hardness values of all barriers on top of each other (the example I already described). This method works best for don't get shot rules, and probably works the worse for high heroic games. As it is already our cover and concealment rules are already the most advance ones that have ever appeared in a d20 game and it would have been that way even if we didn't implement the pass-through rules, but we did implement pass-through rules and I think that officially makes our rules the most awesome ever. That being said the rules take up a lot of space in the combat chapter and so the mechanics used for stacking hardness values together need to be very simple and streamline. My gut feeling is we don't want to use more than a short paragraph to explain the mechanic.

Edit

It occurs to me that the engine block in my first example is probably along the lines of a 50 point barrier or at least a 20 point barrier. We also included empty barrels and in the case of barrels I don't think it makes a whole lot of difference if they are made out of wood or metal, but with if they are filled with liquid or some kind of powder? A filled barrel is probably in the 50 point hardness area, because bullets don't penetrate the kinds of substances that barrels are usually filled with very well at all.

[Squangos]

You could have values for the amount of soft cover rather than the type of soft cover, which would solve the stacking problem. Something like:

• Not a lot: DR 1 (thick glass, overturned mattress, several layers of cardboard)
• A fair amount: DR 3 (thin wood, dry wall, plaster, sheet rock)
• Quite a bit: DR 5 (thick wood, car door, empty barrel)
• Quite a lot: DR 10 (brick wall, stone wall, thin layer of steel)
• A lot: DR 20 (Tree trunk, bulletproof glass)
• An awful lot: DR 50 (statues, sandbags, full barrel, engine block)

Then when the GM needs to rule on how much DR you get from cover, he can say "A park bench, two bicycles and a billboard? That's quite a bit of cover between you, so DR 5." or "You're shooting through two lanes of busy traffic? That's an awful lot of cover - DR 50."
_____

You might be able to use natural language to determine the Defence bonus too (knee-high, waist-high, chest-high, neck-high?), but finding the right terms could be tricky.