Over the years, I've worked with a lot of inventors and seen a lot of games.  Most of the games never made it into a casino at all.  While casinos are more receptive to new games today than they were years ago, the odds of getting your game into a casino are pretty long.  The odds of the game being successful are even longer.  If you look at the games that are in the casino, most of them are poker based and nearly all the rest are blackjack variants.  Once in a while, I'll get an inventor who will try and convince me how desperately the casino needs a game based on neither of those - whether it be dominoes, backgammon, 3 dice or a 14-sided die.