The Gift
Some people in Mythic Europe are blessed with the Gift of Magic. Aligned with the Magical Realm of power, these people are capable of wielding magic. If left untrained, their magical aptitude will usually manifest in idiosyncratic ways, in a specific Supernatural Ability and Virtues reflective of their nature and circumstances. If properly trained, a Gifted child can learn to master the Hermetic Arts and be inititated into the secrets of Hermetic magic. Magi are often very keen on locating promising Gifted children, to be raised as apprentices.
Social Effects
The Gift is unnatural, and repulsive to mundanes and animals. This makes it difficult for magi and other Gifted people to have normal relationships with people. The so-called Gift is a mixed blessing, and the term itself is tinged with irony.
Some characters are blessed with the Gentle Gift, or with a Gift amicable to certain kinds of creatures (see HoHMC). Others have a Blatant Gift, or a Gift particularly intolerable to certain beings (see HoHMC again).
Social Effects in Fifth Edition
The social effects of the Gift have definitely changed from Fourth Edition to Fifth - In Fourth Edition, the Gift provided a penalty to social rolls with mundane beasts and people. (ArM 4 p. 17. p. 35 describes the penalty with regard to normal people and animals for the blatant gift). In Fifth Edition, the social affects of the Gift apply to other supernatural beings as well, including other magi, unless such a being or its race specifically isn't affected by the Gift. Magi in Fifth Edition are able to interact with each other because the Parma Magica now blocks the unease and distrust engendered by the Gift.
The social effects of the Gift are explained on pages 75-77 of ArM5. A lot more text is devoted to explaining the Gift than has been done in past editions, and the description of the social effects of the Gift is harsh and unequivocal. This has led many veteran players, who had interpreted the Gift's effects more moderately, to regard the rules as changed (and these players generally think the change is for the worse). Other people say the description of the Gift in Fifth Edition matches the way they've always played it.
So, the extend of the difference depends on how you played the Gift before Fifth Edition came out. If you think the effects of the Gift have changed for the worse, don't feel forced into a different intepretation just because a new edition came out. You can always overrule the book.
What Causes the Gift
The origins of the Gift are mysterious and unclear. While it can potentially be obtained in the Garden of Eden, it can also be gained by one who undergoes Odin's Sacrifice, meaning it may not necessarily be a Divine gift. Its provenience and nature remain unknown.
Legacy Page
The history of this page before August 6, 2010 is archived at Legacy:the_gift