I can't remember the name of a book I read as a child, before 2005.
The main character is a fairly young girl, I think around 13 years old. I can't remember if she was living in an orphanage, or was some sort of slave, but her life was quite harsh, and i think a Palace or castle was described or referred to.
The story centred around some sort of board game, something like chess. I can't remember if it was played only by two people, but it could be played that way. Lots of people would gather to watch when it was played, and I remember her being average at best at it, if she even played at all in the beginning. This game was also a way of getting out of poverty that she and the others around lived in.
At some point I think she may have gotten lost and may have ended up in part of the Palace, but she definitely should have been there. She encountered some rare variant of reptilian creatures that were perhaps golden in colour, and not as aggressive as the normal wild creatures. I don't think she was bitten, but she definitely had some sort of physical contact with one of her arms, then somehow escaped and ended up back where she usually lived.
After encountering the creatures, her arm was blessed with luck, and whenever she played the game, if she used that arm/hand to move the pieces, she would magically win, as if the game was being influenced by higher powers.
An adult was intrigued by her winning streak and took her under her wing. He played against her and she would always win, and I think he made some sort of connection between her winning and the creatures she encountered before. He wanted her to keep this secret, so he made her play with her other hand against him, which resulted in her loss, and he taught her to improve so she could play without relying on her lucky arm.
That is all I can remember. Any help in finding this would be much appreciated.