Laundry Files: Magic

Casting Spells

Magic is just a highly specialised branch of applied mathematics and there are many different ways to perform the necessary calculations, some use computational sorcery to write apps that cast the spell for them, others inscribe circuit diagrams using pens with conductive ink. Most Laundry agents don't stoop to bloody pentagrams, chanting and ritual sacrifice but the cultists they face often do. Finally it's possible to cast a spell in your own mind, the brain is an incredibly powerful computational device and experienced mathematicians can visualize and compute the necessary algorithms in their head. This mental magic is faster and requires less preparation but those who use it risk K-Syndrome, a rather horrible form of brain damage.

Casting a Spell

When a character casts a spell the player rolls either their Computational Sorcery or Ritual Sorcery skill (their choice).
All spells have a class from 1 to 5 and a character cannot cast a higher class spell than they have in the skill (e.g. a character with Computational Sorcery 3 cannot cast a class 4 spell).

The casting roll is penalised by the class of the spell, making higher level spells harder to cast but a character gains a bonus based on how long they spend casting:
The more preparation put into a spell, the easier it is to cast. This preparation usually involves some form of ritual, whether it be archaic blood rites or connecting a microprocessor to a conductive grid.

Time	Bonus
1 Extra Round	+1
1 Minute	+2
1 Hour	+3
1 Day	+4
1 Month	+5

Example: A character with 3 in Computational Sorcery attempts to cast a Class 3 spell. They roll d6 and add their skill in an effort to get a 6 so normally they would need a 3+. However the roll is penalised by the rank of the spell (-3) so they need to roll a 6. If they spend a minute casting they get +2 and only need to roll a 4+.

Mental Magic

All magicians, whether computational or ritual can attempt to cast a spell using their own brain to perform the calculations but few would intentionally do so. While this technique has its advantages (it's faster, and can be done in any situation) the risk of death is very high. When you invoke eldritch mathematics in your own mind, things from other dimensions can take bites out of your grey matter, resulting in a form of brain damage called K-Syndrome.

Mental Magic works just like Ritual or Computational magic, except:

• You can always perform mental magic, even if you're tied up and gagged. No components, chanting, or preparation of any kind is needed.
  
• It's much faster. Each round that you run the calculations through your mind before casting gives you a cumulative +1 bonus to the casting roll (so it only takes 3 rounds to get +3 instead of an hour).
  
• It's subtle. There are no obvious signs that you are casting.
  
• It's harmful to your Sanity, casting a spell this way almost always results in Sanity loss.
  
• A failure is almost always extremely bad for you and certainly results in K-Syndrome.
  

Spells

Entropy Manipulation
Induce low level chaos in the area that causes a specific effect. The effect must be chosen when the spell is cast and cannot be changed without recasting the spell.
These effects are all stationary.
Sound randomization pattern: Create a spherical area in which people can talk privately. No one outside can listen in, even with a powerful microphone.
Invisibility Field: Create an area of randomised light, rendering everyone in the area invisible.
Start or douse a small fire, make an object to hot or cold to touch.

Exorcism

Gates

Geas

Glamour

Prognostication

Scrying

Summoning

Wards