SOLVED. YA Fantasy read around 2010, book was older. People with magic could shapeshift and something to do with chess/cards and math. Spoilers ahead. [s]

[Tim]

YA Fantasy/Science Fiction read around 2010 but the book was much older. I don't remember much, but there are different cards or chess pieces(?) and people have certain magical powers. Some can change their shape, but only if there is enough mass, so they couldn't turn into very small animals without it hurting.

The book had something to do with math and probability, maybe. The twist was that it wasn't a fantasy book, but really was a science fiction book, that you only found out later on as they were from another planet. They discover a rocket and computer system with people connected to it. That about it all I remember!

[Kris]

Tim, what can people shapeshift into?

Can you describe the main character(s)?

[Tim]

Thanks for getting back to me Kris! Unfortunately I can't remember. I think there were different tribes, and the different tribes had certain magical abilities. I think someone had the power of speed, and another could change shape into maybe animals. That's all I remember really. I think I also remember that their ancestors were explorers that had come to this new planet, but they had forgotten this and it is revealed when the protagonist discovers the rocket ship they had come in.

[Ky]

Sounds like the The True Game series to me. The author is Sheri S. Tepper and the first book in the series is King's Blood Four.

[Tim]

Oh wow yes! That was it, thanks! Now I can go order it.