Graces

A Grace is an an exceptional skill or supernatural ability that people in the Seven Kingdoms can be born with. A Graceling, as they're called, can be identified by their eyes, which will be mismatched and occasionally unnaturally colored.

Information
Graces can be just about anything, from being talented at an odd and highly-specific skill (tree-climbing, swimming, talking backwards), to having an ability akin to magic (mind-reading, invisibility, glamour). A Graceling will only ever have one Grace, but how much they can do with it depends on how broadly their Grace is defined.

The eyes of a Graceling will usually settle a few weeks or months after they're born, occasionally taking a year or two. A Grace appearing past the toddler stage is exceptionally rare. It’s common practice for new parents and nursemaids to frequently check a baby’s eyes for signs of changing.

In most places, Gracelings are looked upon with wear and revulsion, and are little more than second-class citizens. A majority of kingdoms have a law dictating that all Gracelings are automatic property of the king, and will be taken and raised at the court till their Grace appears, at which time they’ll either be given a suitable job in the king's service or dismissed if their gift is considered useless. It’s not uncommon to see a king’s castle littered with Graced workers. Withholding a know Graceling is considered a form of treason.

It is unknown why some are born Gracelings, and if the nature of a Grace is determined at birth or if the person's upbringing has any influence.

Trivia

 * The source of Graces might also be what createsmonsters. Both Gracelings and monsters have unnaturally-colored physical features, and both have abilities beyond that of normal humans/animals. In the prologue of Fire it is noted that monsters crave the flesh of Leck, a Graceling, just as much as they crave each other's.
 * Despite being a fantasy series, Graces and monsters are the only magical elements to ever appear in the Seven Kingdoms trilogy.