Today I thought I'd provide some more details on how magic works!
Casting a spell is an ability check that works just like firing a gun, throwing a punch, deducing an answer to a clue, and so on. You add your MGK (Magick) core value statistic to the statistic of whatever Sorcery or Witchcraft sub-skill you're using, then roll the Flux Dice (taking the highest), and compare the total to a Target Number or opposed roll. The Target Number depends on the difficulty of the spell. Of course, since you can cast whatever you can think of within the limits of your discipline (aka school), the Director sets this TN for you. Assuming, that is, that you're not using one of the sample spells. Here's a sample formula for a Sorcerer with MGK 3 and Kinesis 2, who needs to meet or beat a TN of 7:
MGK 3 + Sorcery: Kinesis 2 + Flux Dice roll (result of 4) = 9. Success!
Sorcery disciplines are: Holography, Kinesis, Metamorph, and Technomancy. Witcher disciplines are: Charm, Elemental, Perception, and Spiritism.
The following text comes from the Spellcaster asset:
Spellcaster. An aspiring Sorcerer or Witcher must purchase this asset and have at least 1 point in any Sorcery or Witchcraft discipline in order to cast spells. If he wants to hurl bolts of raw arcane energy, or boost his natural ‘casting ability, he also needs a magical implement (i.e., a wand) to assist.
Spells. ‘Casters can cast almost any spell that they can imagine, within their spell disciplines and certain natural limits. Magic may be bleeding into the world, but nature has a way of regulating itself. No matter how much imagination a ‘caster has, there isn’t enough magical energy in the world (yet!) for a spell to turn the oceans to blood or cause the forests to wither and die. There’s also a limit to how much energy a ‘caster can channel through his body each day without suffering ill effects.
Casting Spells. Each spell has a maximum range, area or number of targets, and duration. These limits may be defined by a set number or, more often, based on a [MGK + discipline] total. This is displayed on spell lists as the ✪ symbol. To summon magical energy, your character attempts to beat a certain Target Number. If successful, the spell functions. Living creatures, and any items touched by the Flux, may attempt to resist your character’s spell – as seen on the Sample ‘Casting Checks sidebar, below. Non-magical objects have no resistance to spells, though objects held by (or in!) a living being resist in the same manner as that being.
‘Casters require a combination of specific ingredients (i.e., material components) to cast spells. For Witchers, this may be herbs, bones, salt, chalk, candles, and so forth, while Sorcerers use spray paint, computer chips, and so on. Such items are readily available and can be considered part of the Knightwatch loadout.
Counterspells. ‘Casters can attempt to block an enemy’s spell with a counterspell. This requires the character to cast a spell of the same type [MGK + appropriate discipline] and meet or exceed the opponent’s original casting TN. If successful, the spells cancel each other out. If unsuccessful, the enemy spell functions normally.
Spells Per Day. A Sorcerer or Witcher can cast a number of spells per day equal to his MGK score, without harm. For each additional spell cast beyond this limit, the character suffers a cumulative –1 penalty to the casting. Furthermore, any time a ‘caster fails his TN with one of these excess spells, he suffers painful mental feedback and can no longer cast for the rest of his current turn and the entirety of the next. For example, a character with MGK 4 can cast 4 spells per day with no ill effects. On his fifth spell, he suffers a –1 to his Flux Dice roll. On his sixth spell, the penalty increases to –2. On his seventh, the penalty increases to –3, and so on. If the fifth, sixth, or seventh (and so on) casting fails to meet or exceed the required TN, the caster loses all casting for the remainder of the current turn and the entirety of the next. Afterwards, he can attempt to start casting again. Valyant research predicts that areas of Flux exist where such limits do not apply, and that (should the Flux not be stopped) they will eventually envelop the planet.
Modifying Spells. A caster can double (triple, quadruple, etc.) the range, duration, and targets as desired, with limitations. For each improvement, the TN increases by a cumulative one step. Furthermore, the character suffers a cumulative –1 penalty for each improvement. If a modified spell fails, the caster suffers an agonizing mental feedback equivalent to 1 head wound. For example, if a character doubles the range of a TN 9 spell, the TN increases by one step to 11. If he doubled range and duration, the spell increases two steps to TN 13. Likewise, if he triples the range of a TN 9 spell, it becomes TN 13 (doubling takes it to TN 11, and tripling to TN 13). If the modified spell fails to meet or exceed the required TN, the caster suffers 1 head wound and associated penalties.
If the number of steps in a spell modification would increase the difficulty beyond TN 17, simply calculate the appropriate TN (such as TN 19, 21, 23, etc.) as needed. Modifying spells that have a range or target of “Self” to work on other creatures or objects also increases the TN by at least one step.
Learning Spells. For your PC to invoke a spell, determine what you’d like the spell to do. You might want to wave your wand and short-circuit a character’s EyePhone, cast a bolt of ultraviolet light (i.e., artificial sunlight) at a suspected vampire, slow a bullet in midair, raise a wall of earth, or something else entirely. Exactly what you’re able to try is limited only by your imagination. It’s the level of your magic skill specialty, and the difficulty of the spell, that determines what you can actually do. Casting a small fireball at a single person is much easier than conjuring a fiery cloud to rain blazing hail down over a city block. Sample spells for each discipline are listed beginning on the following pages, but your Director has final say on your casting’s TN, range, targets, and duration. Copying a spell your character has seen another ‘caster use is fairly simple; just succeed at a [MGK + KNO] check vs a TN 13 – X (where ‘X’ = your character’s MGK score). For instance, if your MGK is 5, then the TN is 8 (since 13 – 5 = 8).
Wands. Wands are special ranged weapons usable only by ‘casters. To hurl a bolt of raw magical energy, a ‘caster must have a wand to serve as a conduit. For 'casters, this is as easy as firing a pistol and requires only a successful Firearms attack to hit the target. The bolt deals damage equal to the 'caster’s MGK ability. For example, a caster with MGK 4 may fire a magical bolt dealing 4 points of damage. Range varies by distance in the same manner as other ranged weapons. This power bypasses Damage Reduction from armor and shields.
A caster may own as many wands as he can collect, but must choose one as his ‘signature’ piece that he will wield for the rest of his life. Using another wand has a greater chance of failure, equal to [50 – X ]%, where X is the ‘caster’s relevant [MGK + discipline] score. For example, a character with MGK 4 has a 46% chance of failure (50 – 4 = 46) when using a wand other than his signature piece. The wand may be some cheap plastic wand from a toy store, an old wand from a stage magician’s kit, or a petrified bit of wood found in a relative’s belongings. Its composition helps to boost certain spells cast through it (see the Wands chart).
Witchers may only utilize wooden wands, just as Sorcerers are limited to artificial wands. Otherwise, the attack roll has a significant chance of backfire, equal to [90 – X ]%, where X is the ‘caster’s [MGK x 2] score. For example, a character with MGK 4 has an 82% chance of failure (90 – 8 = 82) when using a wand other than his signature piece.
Augment Penalties. Biotech augments disturb your character’s connection to the forces of magic. Each permanent augment applies a cumulative 1-point penalty to all MGK related checks. Non-permanent, easily removable pieces of tech (e.g, the EyePhone) do not cause this penalty.