We analyze spread-spectrum and quantization projection data hiding methods from a game-theoretic point of view, using the bit error rate (BER) as the payoff, and assuming that the embedder simply follows point-by-point constraints given by a perceptual mask, whereas for the attacker an MSE-like constraint is imposed. The optimal attacking and decoding strategies are obtained by making use of a theorem that in addition states that those strategies constitute an equilibrium of the game. Experimental results supporting our analyses are also shown.