The dark (and not-so-dark) arts are part and parcel of the Buffyverse, where anyone with the right books can summon forces from the beyond. Of course, calling on these occult powers does not mean your character can control and use them with impunity. More often than not, magic has unintended consequences. But the real kicker is that even succeeding does not mean everything works perfectly. There is always a price, both for success and failure. You have been warned.
Each spell has a Power Level. This determines the overall strength of the spell—the higher the Power Level of a spell, the more difficult it is to cast properly, and the more damaging the consequences of failure. Additionally, spells have Requirements—the ingredients or ritual components needed to attempt the magical endeavor. Finally, spells have an Effect. This is usually descriptive ("all the body hair is removed from the victim," for example), but can also include rules concepts like damage inflicted, area affected, and duration.
Once everything is in place, casting a spell requires a roll using Willpower and Occultism. Drama Points can be used normally to increase the spell’s chance to succeed.
Witches, meaning those with true power (or in this case, the Sorcery Quality), have an advantage when casting spells. Characters add their Sorcery level to any spellcasting roll, to a maximum bonus of +5. After that, additional levels of Sorcery stop adding up (although they still have other uses). With this bonus, Witches can cast high-power spells with a better chance of success than your typical book-reading spell-flinger.
If the roll fails (i.e, the total is less than nine), the spell doesn’t work — the ritual simply fails. Generally, there’s no other down side here; your character just wasted some time, candlepower and pretty speechifying.
If successful, the roll’s Success Levels are compared to the spell’s Power Level. If the number of Success Levels is less than the spell’s Power Level, something magical happens—but it may not be exactly what the caster intended. The spell’s intent may be twisted or perverted, and the caster may be injured — or even killed — as the magicks draw on her life force to fulfill their purpose. You can decide what happens, or you can roll on the Spell Side Effect Table.
|Spell Side Effect Table
Roll D10 and add to the Spell's Power Level.
|4 or less
||Phew! Lucked out, and the spell still works.
||The spell is delayed. It appears the spell failed, but it will work normally at a time of your choosing (ideally, a dramatically appropriate time).
||The spell works, but it’s less effective than expected. The duration, damage or effect is halved (if not applicable, then the spell is delayed as above).
||The spell works, but the caster is damaged by its energies. The magician takes five Life Points of damage per Power Level of the spell.
||The spell affects the wrong target (you decide who gets to be the lucky recipient).
||Spell has a completely unexpected effect. The magical energies run rampant, often causing physical damage to the area or summoning dangerous entities from beyond our reality. This can also happen if the spell is disrupted during a critical point.
If the roll results in Success Levels equal to or greater than the spell’s Power Level, all’s well and the spell works. Unless, of course, the spell takes an unexpected turn no matter how many Success Levels were rolled. In some cases, a spell might work too well. But no good and true Director would do something like that, now would they?