This page is regularly updated, so it is not necessary to read the whole thread. If you have any questions or suggestions, feel free to post them here, I will update this page.
1) If a mage possesses himself with one of his spirits, can he cast spells or conjure spirits?
A: No, unless the mage possesses the Channeling metamagic ability, the spirit's special attributes override the mage's and the mage loses the ability to wield magic including casting spells, conjuring spirits, and enchanting items. (Street Magic p. 102 sidebar 2nd paragraph)
2) If a mage with the Channeling metamagic ability possesses himself with one of his spirits, can he wield magic?
A: Yes, the mage's special attributes override the spirit's special attributes and the mage can cast spells, conjure spirits, enchant objects, etc. (Otherwise, there is no point for Channeling.) The mage uses his own Magic attribute (not the spirit's).
3) If a mage possesses himself with one of his spirits, can he still control the spirit?
A: Yes, the mage retains complete control over the spirit. He can mentally command the spirit to walk somewhere, pick up something, say something, and so on without expending a service. He can also command the spirit to expend Services as usual. If the mage is possessed by someone else's spirit, he obviously would not be able to control the other mage's spirit without the use of Banishing.
4) Can a mage with the Channeling metamagic ability control a spirit possessing him that is owned by someone else?
No (well, maybe). By the RAW, the channeler only has to allow himself to be willingly possessed, no one has to give the channeler explicit control of the spirit. By this interpretation, in a sense, a Channeler can turn the tables on possessing spirits and can become a tarbaby for hapless spirits. (Street Magic p54). However, it also says that Channeling is used by magicians to "enhance their control over spirits", so it seems that in the spirit of the rules (no pun intended), it would seem the answer would actually be "No" unless the channeler was given control of the spirit (as a remote service) or if the channeler succeeded in Banishing and re-Summoning the spirit.
5) Can people notice the spirit in the mage?
A: Yes. Unless the mage (or the spirit) possesses the Masking metamagic ability (or Aura Masking spirit power), the spirit can be spotted with Astral Perception using the Assensing rules. Furthermore, unless the spirit has the Realistic Form power or is under the effect of a Mask/Physical-Mask illusion spell, a powerful spirit could be noticeable to mundanes using the shamanic mask rules. (Street Magic p. 102 sidebar 1st paragraph. See SR4 p. 168 for shamanic mask rules). Possible manifestations of this phenomena include (but are not limited to) glowing eyes, ectoplasmic wisps radiating from the body, otherworldly voice, and alien spectral facial features. Furthermore, unless the mage has acquired the Channeling metamagic ability, people who know the mage would notice that the hybrid being behaves significantly differently than the mage including a different gait, speech pattern, and possibly a different voice if the spirit was powerful enough.
5 b) What does the possessed character look like?
A: There's nothing in the rules about what a possessed character looks like or if there are any ways to modify that spotting role. P.102 says "Occasionally a possessing spirit’s nature manifests through the vessel in an effect similar to a shamanic mask (p. 168, SR4). Success not only notices the possessing/inhabiting spirit, but also delivers some clues as to what the spirit “really looks like." P. 95 has a little more detail and says "To notice a spirit possessing/inhabiting a vessel, an observer must make a Perception Test and beat a threshold of 6 – the spirit’s Force." If they are using their powers, they may be a little easier to spot: "At the gamemaster’s discretion, the use of the spirit’s powers may create an effect like a shamanic mask, adding a +2 dice pool modifier to the Perception Test." Spotters just get 6 minus spirit's force to spot the spirit in the person even if the possessed character is 10 miles down the street, hiding behind a curtain, wearing a trenchcoat sunglasses and hat, and standing deep in shadow. I've always taken the "traditional" approach and figured a possessed character could have an otherworldly voice ("THERE IS NO DANA, ONLY ZHUUL"), spectral eyes (Spawn), or (at higher force) more exotic effects like ectoplasmic wisps of shadow, writhing skin, and such. So by that paradigm, the possessed character gets perception mods to his concealment roll such as distance, shadow, heavy clothing, etc. Therefore the possessing character could conceal his nature (depending on what the GM says the "special effects" are of the possession) with a Physical Mask spell or even a mundane disguise. For example, an electronic speech synthesizer on the throat would conceal an otherworldly voice but wouldn't do anything to disguise transparent glowing skin.
6) Is the mage/spirit hybrid dual natured?
Yes, which means the mage/spirit hybrid is simultaneously astrally-perceiving and normally-perceiving all the time without the -2 penalty. (SR4 Errata v.1.5 p. 3). If the mage (or spirit) has the Masking metamagic ability, the mage can hide the fact that the being is dual natured.
7) Can a spirit that is possessing someone without Channeling use their Adept abilities?
No because the spirit's Magic attribute overrides the host's Magic attribute and the Adept loses all his adept abilities while possessed. (the example in Street Magic shows a Technomancer losing all his abilities while possessed).
8_) Does a Mystic Adept that is possessed and has Channeling keep access to his Adept abilities?
A: Yes because with Channeling, the Mystic Adept's Magic attribute overrides the spirit's Magic attribute and therefore can cast spells, conjure spirits, and use his adept abilities.
9) Can a person possessed by a spirit with a high force (and therefore a high essence) get a bunch more cyberware installed, using up that additional essence?
A: Nothing in the RAW prevents this. But the spirit might not like being stuck in the same body for the rest of the host's life and if the spirit was ever forced out or disrupted, the host would die instantly. *** Hopefully errata will eliminate this issue by changing the phrase "use the spirit's special attributes" to "use the lower of the host's or the spirit's special attributes". ***
10) Immunity to Normal Weapons:
10 a) Does Immunity to Normal Weapons stack with normal armor?
A: Yes (with clarifications). The extra damage resistance protection provided by Immunity to Normal Weapons stacks with the extra damage resistance from body armor just like the extra damage resistance from Hardened Armor critter power, dermal armor, cyberlimb armor, Mystic Armor adept power, etc. At no time do armors reduce incoming power, but they always give you extra damage resistance dice. However, only the "hardened armor" provided by Immunity to Normal Weapons bounces weapons, so you'd need to keep track of which armor is which (SR4 p. 288).
QUOTE (Frank Trollman)
If you have 8 points of Hardened Armor and 8 points of regular armor and are hit by a 9P attack, then the Hardened armor does not completely stop the attack, and the regular Armor does not downgrade the attack from lethal to stun. But both give you +8 dice to your damage resistance test, which is a lot. Also, AP applies towards each set of Armor/Hardened Armor separately as per the rules, reducing both the DV that they have a special effect against and the amount of bonus damage resistance dice they add.
10 b) Does APDS ammo affect Immunity to Normal Weapons?
A: Yes. Immunity to Normal Weapons power is the same thing as the Hardened Armor power (i.e. is reduced by -4 by non-magical AP weapons) but just doesn't work AT ALL against magical attacks (such as a critter power, adept power, spell, or weapon focus) or non-magical attacks that are made from a substance or energy the spirit is allergic to (SR4 p. 288). As for fluff justification: APDS ammo isn't necessarily made from mundane steel jacketing. You could say that it is made from alchemically purified radical depleted-uranium (called "munchkinbanium" maybe?) which not only gives it armor piercing qualities towards body armor but also against Immunity to Normal Weapons paracritters like spirits and vampires.
10 c) Does shock ammo and shock weapons bypass Immunity to Normal Weapons?
A: No. Unless the weapon or ammo is magical (i.e. a critter power, adept power, spell, or power focus) or is made from a substance or energy the spirit is allergic to, the spirit/host is protected by the full value of the Immunity to Normal Weapons power. SR4 p. 288. From a fluff justification for the Rules As Written, shock weapons like tasers work by running an electric current through an living creature's nervous system, disrupting brain, nerve, and muscle function. Spirits are not living creatures nor do they have muscles or a nervous system.
11) If I have a possession tradition, does my Ally have the Possession or Materialization power?
A: Possession replaces the Ally's Materialization power (just as with all their other spirits).
QUOTE (Synner)
The errata for Street Magic will clarify that, during design, ally spirits can be given either Materialization/Possession (depending on the tradition of the conjuror) or Inhabitation at the initiate's choice (note - don't forget you now have to invest in an ally conjuring metamagic to get an ally in the first place). Inhabitation (much like Materialization and Possession) is not a power you can otherwise buy/assign during ally creation, so such spirits should never possess any combination of the aforementioned powers at the same time.
http://forums.dumpshock.com/index.php?showtopic=1725912) Does a mage have to expend services to make a spirit possess/de-possess a vessel?
A: No (but with clarifications below). Just like with Materialization, the "service" is "Protect me and my team with Guard for 12 hours" or "Kill these people with your powers", you don't spend a service to bring the spirit into the Material world and then another service to have it use physical powers or do a physical task. However, if you just ask for Guard protection, it's possible the spirit will just possess you long enough to cast his power, then return to his home plane. You should specifically ask for "possession enhancement" (i.e. all the benefits of being possessed) as your service in order for the spirit to possess you for 12 hours. However in the case of possessing, de-possessing, then re-possessing a host (for example when trying to enter a Ward undetected while protected by a possessing spirit), it is possible that a grumpy spirit may demand an additional service in order to re-possess a host. This situation would be a good reason to have the Negotiation skill or the Spirit Affinity positive quality. See Street Magic pages 94-95, "Spirit Services":
QUOTE
Therefore, a spirit ordered to use Guard on someone would need to use Materialize or Possession before it could do so, and both actions would only require one service (though it might immediately go back to astral plane while sustaining the Guard effect, depending on what other services it was performing at the time).
13) Does it cost a service to de-possess a vessel?
A: No, it never costs a service to end a service.
14) Does it cost a service to ask a spirit to use a metaplanar shortcut to cross a mana barrier (such as a Ward)?
A: Yes, it costs one service to ask a spirit to use a metaplanar shortcut (p. 94 Street Magic).
15) What is the augmented maximum of a possessed host?
A: (host's maximum + spirit's Force) * 1.5. E.g. A human possessed by Force 4 spirit has an augmented maximum of (6 + 4) * 1.5 = 15.
16) If I bind a spirit, can I make it possess me forever?
A: Yes, but even if the command is "Possess me forever", it still costs you one service every dawn and dusk (i.e. every 12 hours unless you're in Antartica or the Arctic circle). This could get expensive since you still have to re-bind the spirit (consuming binding materials) when you run out of services.
17) Can a possessed car drive itself?
A: Yes. A possessing spirit has complete control over the mechanical aspects of it's vessel, so it can roll a car on its wheels (nice way to save gas), push the touchscreen buttons on the radio, and could even start itself if it uses an old-fashioned mechanical ignition switch. A spirit could walk around when possessing a vessel built with moving parts (such as a manikin, anthropomorphic golem, or chain), but could not walk around when possessing a table or gun. It could fire the gun, but it can't move the gun or aim without using spells or other powers.
18) Can a possession spirit control the electronics in its vessel?
A: Possession spirits (as well as Materialized spirits) can control electronic devices using their built in controls (including AR controls if they have AR gloves and goggles) just like a metahuman. However, they don't have the ability to control electrical devices internally or use its host's DNI to control devices. The example in the book lists starting a car (just like Christine), but it isn't clear if the author was thinking of antique cars that have mechanical ignition switches or cars in 2070 which have electronic fob starters.
[spoiler/]