RIGGED dice! Don't play this game >:(
The dice rolls will typically favor the AI opponents. Trust me, i even jotted down what numbers were rolled and how many times. It usually rolls in benefit of the computer. If you have more than 7 cards, the chance of a '7' being rolled statistically DOUBLES (in Hard mode) even though it should only be like a 1 in 10 chance of it rolling a 7.
This type of tampering of the dice is cruel to the human player because the AI gets control of the robber way more than you and in general has more favorable dice rolls than you. I can't count how many times I was on the verge of winning when SUDDENLY it stops rolling the number I need the most, even though previously it rolled my number about 1 in 10 times, it suddenly rolls numbers for the AI to win (I swear one time it rolled a '3' FOUR times in a row, which the AI just so happen to have a city on that resource).
. Just last night, I had a city on an "8" square. the "8" is one of the more common numbers rolled. But when I had my city on it, it only landed on "8" about 1 in 10 times or something. As soon as the AI put the robber on that square... guess what? It hit "8" about 5 times in a row. I was f'n livid. The game is totally rigged and the difficulty is cheaply made harder simply by giving the probablility of the dice landing on your square a smaller percentage. In real world terms that is totally unrealistic because dice rolls are supposed to be random. Not only that, even when you have cities on the most commonly rolled numbers, the stastical chance of it actually hitting those numbers becomes mysteriously low... but suddenly the AI knows it has to make it up for that because the player will see in the post-game stats how often your number was rolled. To alleviate the cheap dice rolls, it will roll your number as much as it can IF there's a robber on it). Totally friggin rigged man. If they wanted to up the difficulty, they shouldn't change something that is supposed to be randomized and use it against you. Make the AI smarter, unwilling to trade, etc.... But they shouldn't have tampered with the dice rolls. It doesn't make the game more challenging, just cheap).
It's f'n cheap most of the time and will drive you crazy trying to beat it on 'moderate' level.