By spending the right combination of resources, you can build roads, settlements, and cities. At any time during the game you can check the resource cost of each type of building by consulting the legend dialog.
At the start of the game, you have 15 road segments, five settlements, and four cities available. You will not be able to build more of any item than you have available. The identity panel tells you how many of each item you currently have available.
A city is built by upgrading a settlement. When you upgrade an existing settlement, that settlement is again available for building somewhere else on the map.
Buildings must not be placed next to each other. This means that a hex can have, at most, three buildings on it. During game play, you can only place a building adjacent to one of your road segments.
Roads must be placed adjacent to one of your buildings, or one of your roads. You cannot extend your road through a building owned by another player.
The first player to build a continuous path of five or more road segments will earn the longest road award. The length of your road is measured by determining the greatest distance that can be traveled from one point on your road to another without traveling over the same segment more than once, and without backtracking.
This award is worth 2 victory points. Only one player can have the longest road award at a time.
If another player builds a longer road, the longest road award will be transferred to that player.
If the longest road is cut by a player placing a building which divides the road, the ownership of the longest road award is re-evaluated. If after the longest road has been cut, and more than one player has the longest road, the award is temporarily removed from play. If no player has a road of five or more segments, the award is temporarily removed from play.