Bear in mind three essential qualities in all games of intellect: Never to show selfishness or to wound the feelings of your adversary. To be modest with a good game. To lose without ill-temper, and to win without bragging.
There are actually a lot of good reasons to employ randomness in game designs, including smoothing skill gaps, variability, and creating drama. But as with most tools, you get the best results if you know what you're doing and why you're doing it.