Endowment Magic from The Runelords
The fantasy series The Runelords by David Farland (The Sum of All Men and The Brothers of the Wolf, and Wizardborn, so far) presents a system of magical gifts called Endowments. Here is my GURPS conversion of this system.
Endowments are magical gifts of abilities from one person to another. The known endowments are Brawn, Grace, Stamina, Wits, Hearing, Sight, Smell, Feeling, Metabolism, Glamour, and Voice. A person may give an endowment to another and thereby lose the use of that aspect of their character. Therefore, a person who gives their Brawn to another becomes very weak, and one who gives their Glamour becomes very ugly.
Givers of endowments are called Dedicates for they "dedicate" their abilities to another. One must be willing to give an endowment, out of love or duty, for money, or through threat or coercion. Endowments are permanent, until the Dedicate dies, where the recipient loses the Endowment, or until the recipient dies, where the Dedicate gets the faculty back.
One-shot magic devices known as forcibles, specialized to a particular endowment, are used to transfer the endowment. A forcible is a long metal shaft with a head covered in a rune, much like a livestock brand. Each forcible can only be used once. The process is painful to the Dedicate, as an aspect is ripped from them by the forcible; it is nearly orgasmic for the recipient. Forcibles require a special ingredient called Blood Metal, a rare ore that many wars have been fought over. The Item Cost for all forcibles is 1000 ST.
Rulers and their families are often recipients of endowments, as well as other important persons in the land. In the Kingdoms of Rofehavan of The Runelords, Dedicates are honored citizens, and the Dedicates of the royal family are permanently cared for in the Dedicate's Tower on the castle grounds by the King's staff. The royal family never buys endowments, and "good" characters never coerce them, though the bad guy does.
In general, the transfer of endowments is not perfect, so the recipient does not receive as much of the attribute or advantage as the Dedicate loses. All attribute loses (Brawn, Grace, Stamina and Wits) by the Dedicate are rounded up, and all attribute gains by the recipient are rounded down. There is no limit to the number of endowments someone can receive though a point of diminishing returns is usually reached at some point. The main bad guy in the series has thousands of endowments. One favorite wife in a harem has over a thousand Glamour endowments and several hundred Voice endowments.
Brawn: the Dedicate loses half of their ST (rounded up) while the recipient gains half of the lost ST (rounded down). The fatigue levels of both are not affected.
Grace: the Dedicate loses half of their DX (rounded up) and the receiver gains half of the lost points (rounded down). Once a recipient reaches DX 20, they receive only one-quarter of the lost points (1 DX minimum).
Stamina: the Dedicate loses half of their HT and fatigue, and the recipient gains half of the lost total in each category. Hit points are not affected. Once a recipient reaches HT 20, they receive only one-quarter of the lost points of HT (1 HT minimum), though they get the normal amount of fatigue.
Wits: the Dedicate loses half of their IQ and the recipient gains half of the difference. Once recipients reach IQ 20, they receive only one-quarter of the lost points (1 IQ minimum).
Feeling: the Dedicate loses all sense of touch and the receiver gains the Sensitive Touch advantage. Each additional Feeling endowment adds +1 to the IQ roll required for Sensitive Touch. Dedicates of Feeling must be very careful about injuries because they could easily bleed to death without knowing they are hurt.
Hearing: the Dedicate gains the Deafness disadvantage and the recipient gains Acute Hearing/+2. Once a recipient reaches Acute Hearing/+10, they receive Acute Hearing/+1 for each additional Hearing endowment.
Sight: the Dedicate gains the Blindness disadvantage and the recipient gains Acute Vision/+2. Once a recipient reaches Acute Vision/+10, they receive Acute Vision/+1 for each additional Sight endowment.
Smell: the Dedicate gains the No Sense of Smell/Taste (Anosmia) disadvantage and the recipient gains Acute Taste and Smell/+2. Once a recipient reaches Acute Taste and Smell/+10, they receive Acute Taste and Smell/+1 for each additional Smell endowment.
Metabolism: the Dedicate falls into state of suspended animation and ceases to age, while the recipient gains one level each of Altered Time Rate, Regeneration, and Short Lifespan.
Glamour: a Dedicate of average appearance or less gains the Appearance: Hideous disadvantage and the receiver gains one increased level of Appearance. If the Dedicate is of better than average appearance, the receiver gains one additional level of Appearance. Once the recipient is Very Beautiful/Very Handsome, each endowment adds +2 reaction to members of the opposite sex and +1 reaction to members of the same sex.
Voice: the Dedicate gains the Mute disadvantage and the recipient gains the Voice advantage. After the first Voice endowment, the recipient gains +1 in all the skills listed under the Voice advantage.