Something from my home rules. Don't say I never gave you anything.

CURSING
Cursing is a metamagical technique. It requires the Cursing magical skill, linked to Willpower, and the expenditure of good karma.

Cursing Individuals
The magician pronouncing the Curse chooses who the subject of the curse will be, and which of the subject’s skills or attributes he is cursing. He then spends any number of good karma points, and rolls his Curse skill against a target number of four. Every two successes on the Curse skill roll increase the curse subject’s target numbers in that skill or attribute by one, with a maximum modifier equal to the number of karma points spent. Curses have a drain code of (number of karma points spent)M. Only Willpower may be used to resist curse drain.
Physical and Mental attributes may be cursed, as well as any skill. Special attributes may not be cursed.
In order to pronounce a curse, a magician must speak the curse either within a number of meters of the target equal to the curser’s Magic attribute (regardless of whether or not the target can hear him), or so that the target can clearly hear the curse. Curses don’t work through any sort of telepresence or electronic assistance; you can’t curse someone over the phone, or using an electronic loudspeaker.
A curse may also be handwritten for the recipient to find. If the recipient sees the markings on the paper (she does not have to read it, nor even be able to read it), she is cursed. The danger to this is that the first person to see the curse after it has been written will suffer its affect, and that person might not be the intended target.
The curse must be handwritten in hardcopy. Display screens and email don’t count, but a curse written on a sheet of paper or on a wall does.
A curse takes ten turns to pronounce or write, and its effects are permanent until removed. See Removing Curses later in this article.

For example, Nautilus the rigger manages to offend the shaman of an Inuit tribe during a trip to the Transpolar Aleut. The shaman, Seal Finder, decides to curse Nautilus’ Motorboat skill. Seal Finder spends three karma points and rolls his Curse 5 skill against a target number of 4, and scores all success. Dividing his 4 successes by 2, Seal Finder gets a result of 2...and all of Nautilus’ Motorboat skill target numbers will be at +2 until he gets the curse removed. Good luck surviving those Arctic waters, Nautilus.

Cursing Places and Objects
Places and objects may be cursed in a procedure very similar to cursing individuals, with the following differences.
When an object is cursed, the curser must have his hands on the object. Anyone who uses the object suffers the target number modifiers of the curse, regardless of what skill is being employed to use the object. If a rifle is cursed for a +2 modifier, for example, anyone using the rifle gets +2 to all target numbers, whether the rifle is being used with Clubs skill, Rifles skill, Intimidation skill (a -2 instead of a +2), or any default skill or attribute.
When a place is cursed, the pronouncer must be in that place. He must specify what skill or attribute he is cursing. He may then make up to two more specifications for who suffers the effects of the curse in that place. He then follows the procedure for cursing described under Cursing Individuals. The area a magician may curse is equal to the area he may ward: Magic attribute times 50 cubic meters. Cursing a place has a drain code of (karma points spent)S.

For example, Loyal T, a dog shaman in the Ice Gun street gang of New York, is a first level Initiate with the Cursing metamagic and the Curse skill at five. After the Ice Guns lose a shootout in a diner versus the Brotherhood Squad, a rival gang, Loyal T curses the diner.
He spends two good karma points, and spends ten turns pronouncing his curse in the diner (or a portion of it equal to his Magic times 50 cubic meters) one night. He specifies that he’s cursing Intelligence for the Brotherhood Squad. Having specified the attribute being cursed and given one specification of who suffers the curse (the Brotherhood Squad), he may make one more. Knowing that the Brotherhood work as muscle for a Mafia family, Loyal T also specifies that made guys of that family suffer the effects of the curse while in the diner.
He then rolls his Curse skill and scores two successes. Until the curse is removed, any Brotherhood Squad or Mob soldiers for that particular family will suffer a +1 modifier to their Intelligence tests while inside the cursed area.
Alternately, Loyal T could have just cursed the diner, so that everyone who entered it would have suffered the effects of the curse. Or he could have just specified the Brotherhood Squad and left out the Mob family. Or he could have used his second specification so that only blonde members of the Brotherhood Squad, or male members, or ork members, suffered from the curse in the diner.

Detecting Curses
The chances are good that a character will know he has been cursed when it happens. If not, she may begin to suspect it when her target numbers are suspiciously high.
Curses may be detected as an astral signature on the subject through assensing.

Removing Curses
Because cursing is a metamagical technique, it requires the metamagic of cleansing to remove.
Any initiate with cleansing may attempt to remove any curse. To do so, the magician makes a Sorcery test against a target number of (total karma spent on the curse plus curse modifier). This takes a number of Complex actions equal to the karma spent on the curse, and has a drain code with a power equal to the target number and a damage level of D.
If the magician fails to remove the curse, he may not try again for 28 days.

For example, Nautilus wants to get his Motorboat skill uncursed. He goes to a Hermetic mage he knows in Anchorage named Carpenter. Carpenter has the Cleansing metamagic and Sorcery 7.
Carpenter rolls his Sorcery against a target number of 5 (the 3 karma Seal Finder spent cursing Nautilus, plus the +2 curse modifier to Nautilus’ Motorboat skill), and scores a success. After three complex actions, Nautilus is uncursed, and Carpenter resists 5D drain.

I like it. I was a little confused about the karma expenditure but I think I got it now. So, to break it down:

• Curser choose number of good karma points to spend.
• Rolls a Cursing(4) test
• For every 2 successes on Cursing test, a +1 is added to the attribute/skill being cursed up to a limit of the number of good karma points spent.

Is that right?

What about modifiers to the TN of 4? Perpahs if the target of the curse knows how to curse it should be harder to curse them (+1 to Cursing TN). Or, perhaps initiates are harder to curse (+ (Initiate Level) to Cursing TN). Could background count impede a curse on an area? Would it help!? Should foci be harder to curse (i.e. cursing that katana adept's uber-weapon-foci-of-doom ™)? Do cursed foci work as foci?

Interesting ideas.

-- Dash --

can someone remove their own curse without resorting to cleansing metamagic? also, can curses be placed through ritual magic?

How about different TN’s depennding on what your target is?

Cursing a living being
Mundane 4+
Awakened 6 (Magic Rating)
Initiate 6+Initiate Grade
IE & Dragons GM’s Choice
Horrors Immune, can reflect back against caster
Spirits / Elementals Force of spirit

Item
Mundane item 4+
Foci 4+Grade

Area/Building
Area/10 equals the TN for cursing a building. A building 100 square feet would have a TN of 10.

Resisting a curse
A target will resist the curse ONCE with a TN equal to the casters magic rating (adding possible initiate grades).

Dashifen:

Yes, that's right. But karma spent on the curse also makes the curse harder to remove, the TN being karma spent on the curse plus the curse modifier (curse test successes divided by 2, up to the number of karma spent).

No, magicians and/or those with Cursing skill should not be harder to curse, but Cursing may be used as a complementary skill to a perception test to notice the curse attempt.

Yes, background count affects cursing the same way it effects other magical operations.

I hadn't thought of it before, but I do think that a focus's rating should be applied as a modifier to curse the focus. The focus would "work", but with the modifiers caused by the curse in effect.

MFB:

No. Throw curses, suffer the consequences.

Jop:

Curses aren't resisted, but they can be dodged or interrupted. A curse target further away than the curser's magic attribute in meters has to hear the magician speak the curse -- so if she starts firing her weapon in the air, or turns off her cyberears, or revs her engine really loud, she's unaffected.

Also remember that cursing costs karma, so it's not something that a magician is just going to throw around all over the place. This restricts its utility and preserves game balance.