http://games.asobrain.com/A lot of people were wondering how to play the game, so here is in-depth description of the rules.
Settlers of Catan (basic game)
The object of the game is to accumulate 10 points. You gain points by first gathering resources, using them to purchase developments, and some of those are worth points. Each turn, you roll 2 dice and total it up; each resource tile on the map is assigned a number from 2-12 (7 excluded) that represents when a resource is harvested. If you have a settlment adjacent to a resource when its number is rolled, you acquire one of that resource (two if you've upgraded to a city).
Resources: The resources are as follows (actual names may vary): Wood, Clay, Wheat, Sheep, Ore. It takes 1 wood and 1 clay to build a road. It takes 1 wood, 1 clay, 1 wheat, and 1 sheep to build a settlment. It takes 3 ore and 2 wheat to upgrade a settlement to a city. Finally, it takes 1 wheat, 1 ore, and 1 sheep to purchase a development card. Each settlement is worth 1 point, each city is worth 2 points, having the longest road is worth 2 points, having the largest army (I'll explain later) is worth 2 points, and there are 5 development cards that are each worth a point.
Robber: Since none of the tiles are numbered 7, the 6 and 8 tiles are the most likely to produce. When a 7 is rolled, a few things happen. First of all, everybody who has more than 7 cards in their hand must discard half (round down what you throw out, round up what you keep). Note that handsize refers to resources only, not development cards. Next, the person who rolled the 7 moves the "robber" to any tile he chooses. That tile will no longer produce any resources until the robber leaves. Finally, the 7-roller gets to steal 1 resource card at random from the hand of one of his opponents; he must choose an opponent who has a settlement or city adjacent to the robber's new tile.
Soldier: The most common development card is called the Soldier. Playing the soldier on your turn (after the die is rolled) immediately moves the robber and you get to do everything as if you had just rolled a 7. There is no discarding though; only discard on a natural 7. Having 3 or more *played* soldiers could earn you Largest Army. You must have 3 or more, and you must have at least 1 more than whoever currently holds that title, if any.
Settlements: To build settlements, you must first build roads from some of your current roads or settlements. You can not build a settlement on an intersection adjacent to any other settlement/city, including your opponents'. If you have multiple settlements/cities on the same hex, you produce that many more resources when that number is rolled.
Roads: To gain largest road, you must have at least 3 continuous, uninterrupted roads in a path. Roads must be built on the sides of the hex tiles, and may be built on the coast. You must build your roads off of your settlements and cities, and you may NOT build through an opponent's cities or roads. Furthermore, if an opponent later builds a settlement in your road, it interrupts the road for purposes of longest road. You can still build off of your road (I think). To count a path, you must ignore any forks and never count the same segment twice; your path can begin or end in a loop, but can not loop in the middle.
Pieces: You are limited to a certain number of each piece; I don't know the numbers offhand, but it should say under the build category. If you run out of settlements and later upgrade to a city, you reclaim one settlement piece that may be used again.
Setup: The default map has randomly placed hex tiles, with the numbers laid out in a circular pattern; there is an order to them but I don't know it offhand. There are 19 tiles; 1 desert (produces nothing, originally houses the robber), 3 mountains (ore), 4 forest (wood), 3 clay, 4 wheat, and 4 sheep. The first player places one of his settlements and one road off of it. Then player 2 does the same, then player 3, then player 4 (if there is one). Then it goes backwards, starting with the last player, again placing one settlement and one road. The second settlement does not need to be connected to the first in any way. As with standard rules, none of these settlements may be placed adjacent to any other. Finally, each person takes 1 resource for each tile adjacent to the second settlement; so if I place my second settlement between 3 forests, I start with 3 wood. Btw, there are 2 of every number except 2, 7, and 12. Only one 2 or 12.
Turns: First roll the dice. Every player who has a settlement/city on the appropriate hexes gathers resources.. Then you can trade and purchase stuff (technically trade first, but the online version doesn't care). Before or after trading, you may play a single development card, though not one you purchased that turn.
Trading: You can offer any resource for any resource to any player, and you can counter offer as you desire. You may not trade pieces, settlements, roads, cities, or development cards. You may agree to such things as not robbing each other or such, but nothing really holds you to it. Additionally, you may trade to the bank 4 of any 1 resource for 1 of any other. If you built one of your settlments along the coast on one of the special trading port tiles, you may trade at better rates; some of these offer a specific resource at 2 of those for 1 of any, the rest offer 3 of any resource for 1 of any resource.
Development cards: Most development cards are soldiers. 5 of them are worth a victory point each. 2 of them are Road Building (build 2 roads for free; still requires pieces). 2 of them are Year of Plenty (take any 2 resources from the bank). And 2 of them are Monopoly (name a resource and take all of those from any player who has them). I could be wrong on the specifics, the counts, etc. Anyway, you may only play 1 per turn, and never one that you just bought; the exception is victory point cards. You can play as many of them as you like in a turn, even the turn you bought them. Keep them for a suprise victory if you want.
Variants:
Knights and Cities
Seafarers/Alternate board setups.
Different point goals
