So I have a question on Concealment from s spirit. The group has a mage who has bound spirits. These spirits are usually Force 7.
So what they did was use this spirit to enter the area. Meaning any perception test in -7 to the dice pool.

1) Do the bad guys get a perception test when the team enters an area? Since concealment covers sound, smell, etc..
The enemy is not aware they are there.

2) How does suprise work in this situation?

3) if the party has silencer and each member maintains LOS to the spirit they can basically each walk to an enemy. And then do Long Narrow Burst.
Does the concealment drop once they shot?
Is it still -7 dice pool for enemy to percieve them after they shoot since everything is concealed and they have silencer's?

It just seems to over powering since the party can basically walk up to the enemy unaware.

Yes, concealment is one of those powers which works hardly up to force 6 and is overpowered from there on...

1) Yes they get a Perception Test, assuming a) The team is attempting to Stealth, and b) they have dice left over to actually make the Test.

2) Surprise works as normal. If the enemies did not succeed on their Perception Test then they are unaware of the party.

3) First off, LoS is not required to be maintained for the spirit. LoS is required to begin the Power, afterwords it can be Sustained indefinitely (assuming you have enough Favors - have they seen Long Term Binding yet, page 94 of Street Magic?). Concealment does not drop when you attack, and it does not drop if the enemies spot you. Yes, they still get the -Force on top of any other modifier, such as Ruthenium Polymer or Adaptive Coloration, or Silencer/Electronic Firing/Subsonic Ammo.

It is only overpowering if you aren't clever about it. For example: giving the enemies TacNet will help offset it, as will remembering that enemy groups can do Perception Tests as an Opposed Test vs. A Group (SR4A, page 64, and third paragraph of Using Perception, page 135). Also, remember the cheap-and-available Betel (CorpCandy), page 74 of Arsenal as well. Through those few things it's relatively easy to get a +8 to Perception Tests (+1 Betel + 5 Group + 2 TacNet).

The other issue is that really obvious things can be perceived without a test.

Like that guy in an open field using a flamethrower at night. I don't care how much concealment the spirit is giving him, I don't require a test to notice that.

On the group's side, they can avoid that little problem if they keep trying to not get noticed by hiding, sneaking, using cover, silencers, etc. - aka, force the opponents to roll perception. The spirit makes them far more effective then, and is useful at any force.

Also, silencers are amazing in how much they can drop sound level, but not magic. Guns are very, very loud. For example an M16 rifle round is 165 dB. With a good silencer you can reduce the sound level by >1000 times, to 130 dB or so. That's still a thousand times louder then a jackhammer a meter away.

Wait, what? 130 is 79% of 165, or a 21% reduction. Not ">1000 times." 0.1% of 165dB (which could be said, albeit inaccurately, to be "a thousand times quieter"), would be 0.165dB. Moreover, a quick Googling puts the decibel level of a jackhammer right around 130dB (although no distance measurement is given). What are you trying to say, there?

It's not a linear scale. It's a log scale. 30 dB is 1000 times difference. To be precise "A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities." So technically the sound of a rifle discharge is a thousand times more powerful without a 30 dB suppressor.

However it will appear a listener to be a difference of 8 times, either louder or quieter.

That makes much more sense, thank you. (IMG:style_emoticons/default/smile.gif)

This is the salient point here for me. The spirit Concealment power (esp at high force) can be pretty useful when you are sneaking around, but shouldn't come into play so much during combat (unless the PCs are attacking from concealed positions) or if they are standing out in the open (Concealment will help, but the +6 or more DP bonuses for spotting something obvious should effectively nullify the Concealment DP penalty).

My group uses Concealment as a dicepool penalty to Ranged Combat Tests, essentially adding it to the Visibility Impaired option of the Ranged Combat Modifier Table, page 152, SR4A.

That's quite an interesting idea. I may yoink that.

Doesn't the spirit have to be manifest? So that's a mighty fine force 7 water elemental you have there sir:)
Also wouldn't a force7 power shine like a beacon on the astral?

Do you have a quote that states that a spirit has to manifest?

I do not recall reading that a Force 7 power has a Force 7 astral form or such an equivalent with respect to astral perception or assensing.

From the critter power chapter main ule book.
"Note that in order for a creature to use a power against a target, they must share the same “state:” astral or physical. Astral forms cannot affect physical targets, and vice versa (see The Astral World, p. 191)."

The second thing I'm not ure of but all magical effects are visible on astral so, maybe?

1) Do they need to be on the same plane to sustain it?

2) On your second point, do you have a quote for that?

1) it becomes kind of moot if they don't no?
2) I would take a look at the basic magic chapter if I was you. There is also the assessing test table that might give some guidelines.

1) Then it is moot, since they don't.
2) I already did. Which is why I am pretty sure that powers per se do not show up on the astral.

Why did you ask then?

Because I thought maybe you found some obscure quote somewhere that stated so.

"Materialization
Type: P • Action: Complex • Range: Self • Duration: Sustained Certain astral critters are capable of projecting themselves into the material world, thus allowing them to interact with physical beings.
When materialized, critters may affect physical targets. Additionally, materialized critters gain Immunity to Normal Weapon"

I think that's good enough no?

Please explain your reasoning.

My reasoning goes thusly, the spirit materializes. It then uses Concealment because when(not while) it is materialized, it can affect physical targets. Once the targets are affected, it dematerializes and sustains the effect.

1) No. They need to materialize to cast it, then they can go to their home plane and sustain it forever, or until they grow bored.

2) Concealment works on the astral.

The quote says they have to be on the plane they wish to interact with. Can I get a quote that says that they can sustain from another plane?

When it comes to powers being visible on the astral just like spells it seems that way from the assensing table. With three successes on an assensing test you can see the astral signature of a critter power. One more and you can tell what type of spirit caused the effect.

Thats my reasoning anyway.All things mana can be seen and interacted with on the astral.

This strongly suggests that Concealment can be sustained from another plane.

You have my apologies with respect to the astral signature caused by the spirit. However do note that going by the Assensing table it does not matter whether how powerful the effect that created that signature, it remains a flat 3 successes to detect the signature and 4 to tell its origins. I think the table also assumes that in order to detect that signature in the first place, you have first detected the subject the signature is on.