"From the bunker" misses an important point

[Plane Sailing]

The "from the bunker" article about Cover and Concealment on the wizards d20 modern site is interesting, and I like the way he talks about using another person as "cover", but the author misses one very significant point about concealment, summed up by his generalisation

Concealment provides substantial benefits, but it isn't as favorable as cover.

While his examples which illustrate this point are fine as far as they go, he completely misses the key benefit of concealment as a game convention - which is that it depends on an additional die roll.

Why is this significant? It means that someone can roll a 20 to hit and still miss due to concealment, even though no amount of extra cover can help you at that point... If the mook needs a 20 to hit you because of your defence bonus, you can step behind 90% cover and be no more difficult for him to hit! You're only chance of being harder to hit at that point is to have concealment.

I liked the article, and I think it is just a shame that he missed this important element of the cover vs concealment argument. I would guess because he was thinking in real-world terms rather than game conventions.

Cheers

 

[Ranger REG]

True, you can still miss, but the most concealment can provide you is a 50% chance. Also, any special attack that inflicts Area of Effect can ignore concealment, unless you can prove to me that a grenade shrapnel has to have a lock on your body to hit you.

 

[Plane Sailing]

True, you can still miss, but the most concealment can provide you is a 50% chance.

You're missing the point here though - it is an *additional* 50% miss chance, after all the other rolls are made.

How about I put it this way... Concealment can protect you from a critical hit, cover can't (by the rules mechanics).

 

[hong]

How about I put it this way... Concealment can protect you from a critical hit, cover can't (by the rules mechanics).

Cover can certainly protect you from a critical hit, if the cover bonus to AC is enough to make the confirmation roll a failure.

 

[Plane Sailing]

Hey, I was just struggling for an easier example to make the point I'll argue that I was talking about stopping confirmed criticals with concealment.

Yep, thats what I was talking about!

 

[takyris]

My party will almost always take concealmnet over cover. Cover decreases an enemy's chance to hit you by some specific amount, an amount that no longer applies once they need a natural 20 to hit you. Concealment decreases their chance of hitting you by a percentage.

Actually, I'm curious as to which is better...

Let's take an enemy who needs a 11 to hit you.

Chance to hit and damage: 50%

Half cover: He needs a 15.
Chance to hit and damage: 30%

Half concealment: He needs an 11, and he has a 20% miss chance.
Chance to hit and damage: 50% x 80% = 40%

Cover is better at half cover and half concealment.

Three quarters cover: He needs an 18.
Chance to hit and damage: 15%

Three quarters concealment: He needs an 11, and has a 30% miss chance.
Chance to hit and damage: 50% x 70% = 35%

Cover is better at three-fourths cover and concealment.

Now, for an attacker who needs a 16 to hit you:

Base chance to hit and damage: 25%

Chance with half-cover: 5%
Chance with half-concealment: 25% x 80% = 20%

Chance with three-quarters cover: 5%
Chance with three-quarters concealment: 25% x 70% = 17.5%

Now, for an attacker who needs a 6 or higher to hit you:

Base chance to hit and damage: 75%
Chance with half-cover: 55%
Chance with half-concealment: 75% x 80% = 60%

Chance with three-quarters cover: 40%
Chance with three-quarters concealment: 75% x 70% = 52.5%

Attacker who needs a 2 or higher to hit you:

Base chance to hit and damage: 95%
Chance with half cover: 75%
Chance with half-concealment: 95% x 80% = 76%
Chance with thee-quarters cover: 60%
Chance with three-quarters concealment: 95% x 70% = 66.5%


PS, you're right that concealment can negate a crit, but the general percentage seems skewed toward cover. I confess that that's not what I expected to find -- I thought that at one end of the spectrum or the other, concealment would be better. But it is at best equal to cover, and usually a ways behind it.

-Tacky

 

[Mistwell]

Interesting. Well, screw the smoke grenade, duck behind that car!

 

[Roland Delacroix]

I find myself liking cover more for the Reflex save anyway. Applies more in D&D but even in d20 Modern it can save your bacon.

 

[Pagan priest]

Ah, yes, but remember: with total concealment, they need to guess where you actually are... wrong location means miss chance is 100%

 

[takyris]

Well, sure. And with 100% cover, they can't target you even if they know exactly where you are. At 100%, either one of them is pretty good.

-Tacky