Magic
Most of the Arcana work normally in the Underworld. Awakened magic works by drawing down the natural laws of the Supernal Realms and imposing them upon the Fallen World, but such magic does require that a given Arcanum’s purview be represented. Put another way, an environment completely devoid of matter, if such a thing were possible, would render the Matter Arcanum nearly useless not because it wouldn’t work, but because there would be nothing for it to work on. Similar principles are at work in the
Underworld, as discussed below.
Death: For the most part, the Death Arcanum works normally, but it is easier to use in the Underworld. All Death spells receive a +1 modifier in the Underworld. In addition, the mage may use factors in Death spells as though her rating was one dot higher. For instance, the Death spell “Suppress Other’s Life” could be used at sensory range at Death 4, rather than Death 5. This bonus does not increase the mage’s rating in Death for the purposes of what spells she can cast, only in applying factors.
Also, spells that deal with Twilight (Touch of the Grave, Twilight Shift) do not work in the Underworld.
A mage can open an Avernian Gate with a Perfecting Death spell (Death 3), regardless of whether she knows the key. Opening a gateway into the Underworld without an existing Avernian Gate requires a Making Death spell (Death 5).
Fate: Works normally, and can be used to affect the Old Laws of Dominions (see below).
Forces: Works normally. Spells that allow reception of radio waves and the like obviously have little utility in the Underworld.
Life: The beings in the Underworld, for the most part, are not alive and cannot be affected by this Arcanum. Mages can use Life spells on themselves or other living travelers, but Life cannot be used to affect the environment.
Matter: Works normally.
Mind: Works normally, except that spells like Beast Control do not function on psychopomps.
Prime: Works normally.
Space: It is possible to scry for a ghost in the Underworld, subject to the usual modifiers to sympathetic magic. If the mage is not in the Underworld, she can only scry for the ghost if she is also a Master of Death. Teleportation within the Underworld works normally, but opening portals to the living world is, again, only possible for Masters of Death. Other than that, the Arcanum works normally.
Spirit: This Arcanum has little utility in the Underworld. The beings there aren’t spirits, after all, and as such aren’t subject to these spells. A mage can use spells like Coaxing the Spirits on objects that he brings with him, but spells meant to summon spirits to the Underworld are automatically considered vulgar in aspect and suffer a -5 penalty.
Time: Works normally, except that Postcognition spells encounter the same penalties and difficulties as The Spirit’s Touch (p. 55).
Laws
Unless the Old Laws of a given Dominion mention mages specifically, they are considered living beings under those Laws. It is possible, however, for a practitioner of Fate to circumvent those Laws, at least temporarily. Using the Alter Oath spell (Fate 3), the mage can attempt to break one of the Old Laws without attracting notice. This imposes a -10 penalty on the spell, however.
The mage can also use the Fabricate Fortune (also Fate 3) to avoid notice after she has already broken one of the Old Laws. In this case, the Resistance of the responding Kerberoi is subtracted from the mage’s casting pool. Finally, a mage can use Death 3 to alter herself so as to appear dead for the purposes of a Dominion’s Laws. If she wishes to use this tactic, it must be done before she enters the Dominion.