There are no gospel truths in Settlers of Catan strategy, as the game is designed to test the limits of a player's decision-making adaptability. However, a good player generally has a good memory, an understanding of basic probability, a cool head, and good rapport with the other players. The following section addresses fairly axiomatic strategic considerations. Controversial ones may be discussed on the discussion page.
Initial placement
The foundation for winning every game is laid during the initial placement phase. Common considerations include wanting a nice combination starting resources, seeing nice expansion spots within striking distance, or long-term planning to take the Largest Army or Longest Road. Some advanced players place with macro strategies in mind, such as those listed under the Victory points breakdown bullet point. Since the layout and properties of the board are different from game to game, and every player has personal priorities when choosing a position, this debate is left for the discussion page. The fastest way to learn how to place properly is to do placement exercises with a mentor.
Building order
Every resource gain has a relative cost. In other words, when a player gains resources from a roll, more often than not one or more of his opponents gains resources as well. Thus it is advantageous to have a production advantage over others on probable numbers and useful resources. Players should make decisions on building order with this in mind. For instance, a city upgrade tends to increase production more than the purchase of a new settlement. Likewise, building a principality increases production while taking the Longest Route does not.
Sometimes more than one player starts the game within striking distance of a good expansion spot. A player should be aware of such situations, and if the spot is a priority (for instance if the player will be trapped with no where else to go without it), then the player must work towards building that settlement before anything else.
Once a player has decided on what to build next, a change of plan is usually suboptimal from an efficiency point of view, particularly if several turns have already been devoted towards realizing the original plan.
Resource movement
Pay attention during all players' turns. A sharp trader should know the approximate value of each resource to each player at each turn, and use this information profitably. The production and trading of resources is public, but resource cards are held face down, which means that an alert player with a perfect memory can know exactly what everyone has in hand, whereas the inattentive player will often be wondering (or asking out loud), "Does anyone have grain?". The market value of a resource changes with any imbalance of supply and demand, but more importantly its value inflates when it enables a key purchase. When offered a trade on another player's turn, consider what the rolling player will build and proceed with caution.
Don't play with fire in the endgame. Absolutely refuse to trade with someone who may be in striking distance of victory. Unwittingly providing the resource necessary for the final victory point is... a blunder of a magnitude that is difficult to put into words.
Robber control
Don't waste robber control when you've got it. At a table of advanced players, one cannot afford to miscalculate who the strongest player is, at any given point in the game. Since all resource production has a relative cost, a quiet lead that goes unaddressed can snowball until the leading player has a firm grip on robber control (i.e. free reign) for the remainder of the game. Prioritize winning the game over getting the emotional satisfaction of robbing revenge.
When a player is close to being able to build something, he may need to rob the opponent who possesses the resource that he needs. Generally speaking, a leading player can better afford to choose robber placement by this criteria.
Victory points breakdown
Q: How many ways can one make change for a ten, with settlements, cities, roads, armies, and victory points?
A: 4 cities and 2 settlements? Yes, but a game rarely lasts long enough for this to be a viable strategy. Think again.
A: 4 cities and the Longest Road? Yes, a timber/grain/ore/brick strategy, getting warmer.
A: 3 cities, the Largest Army, and 2 victory point cards? Yes, a grain/ore/wool strategy. A few advanced players get kind of stuck in this mode.
A: 3 cities, 1 settlement, the Largest Army, and a victory point card? Yes, usually the product of a grain/ore/wool strategy supplemented with a decent supply of either timber or brick.
A: 3 cities, 2 settlements, and either the Longest Road or Largest Army? Yes, this outcome might result after a player gains an early production advantage, by building cities before others could.
A: 2 cities, 4 settlements, and either the Longest Road or Largest Army? Yes, a likely result of the most straightforward of strategies, involving all the resource types, though slightly dependent on how fast a player can build his first city.
A: 1 city, 5 settlements, the Longest Road, and a victory point card? Yes, a player owning 7 intersections had better have the Longest Road (dependent on good roading form). This strategy is luck-dependent if a player finds himself stuck at 9 points with no settlements, left hoping that a victory point card will materialize. However, a player who has acquired the victory point card at some point earlier in the game may safely pursue this outcome.
A: 5 settlements, the Longest Road, the Largest Army, and a victory point card? Yes, sacrificing cities for development cards, risky, but feasible.
Extrapolate to the other boards. Bear in mind that some (but not all) of the sea games permit a new two-point play, building a settlement on a secondary island. On the Great Crossing maps in particular, the rules governing trade routes enable a player to make a huge, multi-point play to end the game very abruptly.
