None of them change the fundamental feeling that Catan brings to the table, but they do offer a nice twist on it. They've created house rules that alter the game in big and small ways. People have been playing so much that standard Catan isn't enough for them anymore.
It's no mystery why the game's been translated into 30 different languages. That same roll could start an equally as decisive chain that lands you in fourth place. One roll of a seven could start a chain reaction that leads you to victory. Settlers of Catan's standard set of rules has a wonderful mix of skill and randomness.
