Bests & Worsts Reviews from Amazon

I got this expansion along with the original game and played it after playing a couple games with the original rules. The basic changes to the original game include: 1) Instead of the development deck, you now have three progress decks (sciences, trade, and politics) which offer a broader selection of usable cards than the development deck and it's 90% knights and 10% events/actions. These decks correspond to three possible areas of improvement (see next item) and have some interesting effects (everything from allowing you to take cards from another player to pulling resources for free). 2) Cities can now be improved. You get a set of flip cards that you flip as you purchase city improvements. There are two benefits to city improvements: a) when you achieve the 3rd level of improvements you gain some bonus like the ability to trade two of any commodity for one resource or commodity (note: as commented on, this is not like the harbor benefit of 2:1 resources which limit you to trading resources for resources; however, it still comes in handy despite the limitation), and b) each improvement increases the changes you'll get to pull from one of the three progress decks. 3) The addition of an event die that you roll along with the standard 2d6. The event die will either move the barbarians closer (50% chance) or trigger a chance to pull from the progress decks (16% chance). As mentioned, city improvements increase your chances of scoring a card when one of the progress areas are rolled (i.e. if you get a 1 or 2 on the red die and a blue icon on the event die and you have the first city improvement in the science area, you can draw a card). 4) barbarians have been added on top of the robber that still plays as it does in the original game; the barbarians show up after the barbarian icon shows up on the event die (which is more often than not). When the barbarians reach Catan and if there aren't enough knights in play to protect Catan, then the weakest player (in terms of knights) who has a city will lose that city (it gets downgraded to a settlement) as it gets razed by the barbarians. 5) knights are now pieces in play rather than a drawn card; they can bump other knights and the roober and play a crucial role in dealing with barbarians: if the number of knights who are active exceeds the number of barbarians (= number of cities in Catan), then the players win and the player that contributed the most will receive a special Defender of Catan card (ties result in progress card draws) which gives you a victory point. 6) Lastly, to make things interesting, there are commodities now, coin, paper, and cloth (which correspond to iron, wood, and wool resources) which are primarily used to buy city improvements. You get them if you have cities (i.e. instead of getting 2 iron if you have a city next to an iron spot, you get 1 iron and 1 coin). Yes, it's definitely more complicated than the original rules but it offers a choice for anyone who wants that complexity (me!). It makes the game deeper and in some respects fixes issues I had with the previous game (like the knights being way too easy to pull up off the development deck given their numbers). Once you get used to the rules (one or two games will usually do it), things move along and tides can turn pretty quickly (like when you were unable to active your knights before the barbarians came and you end up losing a city...or when Catan still wins but you just handed your opponent a Defender of Catan card which secured another victory point). All in all, if you liked the original game and are either bored with the simpler rules or want to mix up the game a bit more, then I highly recommend this expansion. The added rules and expanded progress cards and city improvements really evolve the game in a good way and bring out the best of this game. Oh, and note that you need to use this with the 4th edition (Amazon made sure to label these with that big "New 4th Edition!!!!" tag...). I never had the original versions so it didn't matter to me but some reviewers seemed to have an issue with getting the wrong edition so...