The issue of how arcanoi affect vampires and how disciplines, particularly necromancy, affect wraiths is a complex one. In order to simplify the question we have tried to break down powers into three distinct classes:

1. Those powers which are able to cross the shroud
2. Those powers which are unable to cross the shroud but can affect different creatures on the same side of the shroud.
3. Those powers which are limited to a particular physiology/biology.

Most wraith powers are designed to cross the shroud while only a few disciplines have that capability. Both groups have a number of powers which are specific to their own physiology. In each case we will list which arcanos/disciplines fit into each category and include some notes about certain special cases.

The notes presented here are guidelines mainly for Storyteller use in arbitrating cross shroud difficulties. For additional information see "Buried Secrets" for White Wolf's tabletop Oblivion series.

For the most part vampires count as mortals with regards to wraithly powers. Anything that affects human will usually affect vampires in a similar manner. For additional guidelines see the Risen rules.

Class 1, Powers that cross the shroud: Embody, Fatalism, Flux, Inhabit (as appropriate), Intimation, Keening, Lifeweb, Mnemosynis, Outrage, Pandemonium, Phantasm, Puppetry, Usury.

• These arcanoi can be used by wraiths in the shadowlands and work on vampires in either the skinlands or the shadowlands.
• Usury generally costs an additional point of willpower when used on vampires.
• The power of Obliviate attacks he soul directly bypassing the flesh. As a result it negates any powers of fortitude the vampire may possess. However, since it is affecting the soul directly the vampire may spend one point of willpower for a retest on the extended challenge.
• Mnemosynis: will detect any vampire using obfuscate and astral projection. Vampires using possession will show up as two minds cohabiting the same body unless conditioning was used on the "suit".
• Any powers that allow a wraith to send her corpus across the shroud can only be used one at a time. For instance it is not possible to use the Inhabit power of Ride the Electron Highway while using Flux to create an automaton. The same holds true for trying to puppeteer while being Embodied. The wraith must drop the first power before initiating the second.

Class 2, Arcanos that will work on Vampires on the same side of the Shroud: Argos

• Since Argos draws its powers from the Tempest it generally only works on this side.
• Should Oubliette work on the other side of the shroud if invoked on this side?

Class 3, Arcanos that only work on wraiths: Moliate, Castigate, Displace, Connaisance, Behest.

• The damage from Moliate Arcanoi such as Martially will work on vampires on the same side of the shroud. However, any power such as rend which require the shaping of corpus can only work on wraiths/plasmics.
• Castigate powers generally only work on creatures with a shadow.

Ultimately, the storyteller should use a certain measure of common sense to work through any questions they may have about how arcanoi should interact with vampires.

The most important thing to remember is that virtually all vampires are unable to see across the shroud. Even mediums with their sensory awareness of wraiths in the local vicinity can not actually see them. This proves something of a disadvantage, countering the wraiths disadvantage of a lack of a physical presence. Most disciplines, while they will work on wraiths, will not cross the shroud. There are however a number of important exceptions.

Class 1, Disciplines which can affect wraiths on the other side of the shroud: Auxpex, Melpominee, Necromancy (certain paths)

• Auxpex will cross the shroud. However, it requires the ability to actually see the wraith in question, either through the use of shroudsight or speaker with the dead. Medium does not qualify as sight.
• The paths of Sepulcher and Ash are designed to affect wraiths and the shroud. Bone is specific to zombies and Mortus is specific to vampire biology so neither of them will affect wraiths.
• In the case where a wraith is on the same side of the shroud as the necromancer, the test for Necromancy is static.
• The bond created by Haunting is very similar to the connection binding a wraith to his fetters. As a result the lifeweb power of sever strand can be used to break the Haunting.
• Like Auxpex, Melpominee generally requires line of sight. If Melpominee is performed from within the shadowlands it will not cross back, however.

Class 2, Disciplines which will not cross the shroud but will affect wraiths: Celerity, Chimerstry, Dementation, Dominate, Fortitude, Obfuscate, Obtenebration, Potence, Presence, Protean, Thaumaturgy (Conjuring, Flames, Mind)

• Physical disciplines require being able to touch the wraith in question. (Includes wolf claws, tongue of the asp)
• Chimeristry can only be used in the skinlands.
• Dominate: Forget Mind will leave a suture which can be seen by a mnemoi using an appropriate power such as soul keeper.
• Fortitude only protects against those powers that do physical damage, excludes such powers as Obliviate.
• Remember, wraiths can use their innate heightened senses to see through Obfuscate regardless of which side of the shroud they are on. However, the bonus trait system given in laws of the Night Rev. is not appropriate to wraiths using their innate Heightened Senses as there are no levels with a wraiths abilities. Therefore any challenges involving Auxpex/obfuscate and a wraiths heightened senses neither side gains any bonus traits.
• Generally, wraiths can not see through Obtenebration. However it only obscures what is seen in the skinlands, not the shadowlands.

Class 3, Disciplines which are specific to vampire physiognomy: Animalism, Obeah, Quietus, Thanatosis, Thaumaturgy (Blood, Destruction), Vicissitude.

• Embodied wraiths are not flesh. They are more akin to illusions made solid. Fire will damage but acids require a substance to react with.

It is not possible to characterize every possible interaction so storytellers are best advised to rely on common sense when the rules fail you.

Retests and Wraith Arcanoi
In most cases the issue of retests is straitforward one. For instance wraiths can learn most any ability that vampires can, certainly all of the abilities used for discipline retests are available to wraiths. However, there are a few of the arcanoi retests that vampires do not have access to. For each of these, we will give a recommendation for a possible substitute. Regardless of which skill is chooses as the retest be consistent. Pick one retest for vampires and stick with it, do allow ambiguity to multiply the number of possible retests.

Phantasm - Dreamcrafts: Since vampires have no direct contact with dreams (Excepting certain Sabbat Thaumaturgists) we recommend using the vampires primary Expression (Poetry, Art, etc.) skill. Art is the result of dreams and the creator of future dreams in others. Therefore an understanding of Art lends to it an instinctive understandings of the power that dreams have over mortals. Other options include:

Puppetry - Performance (Puppetry): While Puppetry is not a common skill it is one that vampires can learn. However, if you would prefer a more common skill we recommend that you use medicine for both the Human and Medicinal Arts.

Mnemosynis - Memory: Investigation or Subterfuge. Generally we recommend investigation as it is more appropriate to the nature of the arcanoi. However, it could be argued that subterfuge is appropriate for defending such an attack.

Moliate - Soulshaping: In general this arcanoi should never present a direct effect on a vampire. Most encounters with Moliate will usually involve powers like martialry. Therefore, the appropriate retest will be something like dodge, brawl or melee depending on the circumstances. If a vampire wishes to detect a Masque employing a high level of Moliate to blend into the surroundings (literally) or to detect changes due to moliation then the correct ability to use is bodycrafts. Obviously most vampires will not be able to due this unless they have some other supernatural power of detection.

Important: Wraith Lore should never be used as a retest for an arcanoi. Wraith Lore specifically deal with general knowledge about the world of wraith, its inhabitants, politics, and cultures. While it might tell a vampire what effects are possible to do with arcanoi, it doesn't deal with the specifics of how the powers operate.

There are a few rules regarding vampires in the shadowlands. The first is the difficulty that they have in feeding. There are no humans for them to feed. As a result it is necessary for them to return to the skinlands every time they wish to eat. Usury can (in theory) be used as a substitute for feeding.

Vampires however continue to need to sleep twelve hours every day. However, they will not be harmed by the daylight. This can create a strange situation with vampires sleeping at night and not the day if the vampire moved from one side of the earth to another time zone. However, if they return to the skinlands during the day they will find themselves overcomed by lethargy.

Necromancy works basically the same on either side of the shroud. For instance shroud sight will allow a necromancer to see from the shadowlands through the shroud and into the skinlands. Lifeless tongues works similarly allowing conversation to pass through.