The best Catan expansions, ranked by what they add

In the base game there is really one plan: build settlements and cities faster than everyone else, which is why small edges like your seat and your opening matter so much. Cities & Knights adds a second axis. Cities next to mountains, pastures and forests produce one resource plus one commodity, and commodities buy improvements in three tracks that unlock abilities and progress cards. Meanwhile a barbarian ship sails toward the island, and its strength is the number of cities on the board. If the knights fall short, the least defended cities pay for it.

Ore and wheat was the best plan we tested in plain Catan (+14% against a fair share). In Cities & Knights cities do even more work: only cities make commodities, and the barbarians count them. We haven't simulated the expansion, so take that as a reason to try it, not as a result. Our Catan strategy analysis has the base-game numbers.

Seafarers is the expansion to buy when the base game has gone stale but your group doesn't want a heavier game. Each scenario sets up a different archipelago and usually a different target score, so the variety is in the maps rather than the rules. In the first one, bonus points for being the first to settle a new island turn the early game into a race. If you want more after nine scenarios, the Legend of the Sea Robbers box adds a four-scenario campaign on top.

If Seafarers is Catan with water, Explorers & Pirates is a different game with Catan's production engine underneath. You move ships across the sea, carry settlers to new islands, and compete for missions, each with its own bonus card. It is close to the top spot for groups who play a lot. We rank it under Cities & Knights because it asks more of everyone at the table for a similar amount of new decisions.

Traders & Barbarians is the expansion for groups that like Catan as it is and want to tweak it. The event cards are the variant we would try first: a deck of number cards replaces the dice, which evens out the hot and cold streaks that decide so many base games. The two-player rules use neutral players to make a duel on the board work.

With six players, waiting for the dice to come back around is the problem. The 5th edition fixed it with a special building phase between turns. The current rule pairs players instead: while one player takes a full turn, a second player gets an action phase to trade with the bank, build or play a development card. The rule first appeared in the Starfarers 5-6 player extension and is now the official rule for the whole series; owners of the older 5-6 boxes can use it too.

One catch for every big group: the 5-6 boxes don't stack across expansions. Six players of Seafarers means the base game, Seafarers, the base 5-6 Player Expansion and the Seafarers 5-6 Player Expansion.

Starfarers keeps the heart of Catan (produce, trade, build, expand) and adds a ship you build up piece by piece. It is the best pick for a group that wants something new but would rather buy one box than three.