You would like to think that chess would be a rather noble game that was somehow exempt from the concept of cheating, but that is not the case. However, perhaps the most surprising thing is that we can go as far back as 1561 to see that the idea of trying to have any kind of an advantage over people is hardly new.
This book is referred to as being a book all about strategies for playing chess, and they are quite implicit when they state various ways in which you can try to get one up on your opponent. In the book, it tells you to play with the sun behind your back so it then blinds your opponent, or if you are playing in the evening and using light from a fire to then use your hand to create shadows on the board to hide or confuse.
OK, so it is hardly going to be the crime of the century, but it still comes across as being unfair in your approach so perhaps the game has never been as noble as we would like to think.