Yes, Ron did really get hurt in the game of Wizard's Chess. Although not lethal, Ron sacrificed himself with the expectation of getting killed in that game. This might be because the chess pieces were designed to thwart an adult who would want to steal the Philosopher's Stone from where it was kept. Since Ron is a boy, he didn't get the full blow of being hit by the chess pieces. Instead, the chess piece he sat on was completely destroyed and Ron fell to the ground, only to suffer minor injuries. Frankly, the chances of Rowling writing off one of her major child characters in a children's book that early was slim to none.