Hidden rules and randomness is intentional game design It causes a feeling in uncertainty, which is closer to a gambling game. Randomness prevents the player

Hidden rules and randomness is intentional game design It causes a feeling in uncertainty, which is closer to a gambling game. Randomness prevents the player to form strategies that allows him to win must of the time. Uncertainty is a bit similar. If the player could figure everything out, there would be less suspense. The players are frustrated because they naively expect that they should always be able to determine things in advance so they can be experts at the game and know if they can win or not. Sprinkling some randomness at such game is smart game design.