Bank and Port Trades: When 4:1 Is Fine and When It's a Leak

The bank never says no. It never haggles, never holds a grudge, and never asks what you are building. That is exactly what makes it dangerous.

This lesson is about the trades you make with the supply: the 4:1 bank trade and the better rates from ports. Used well, they turn dead cards into points. Used carelessly, they drain your hand a few cards at a time, and you never notice where the game went.

What trades can you make without another player?

As you saw in Lesson 3, there are three rates for trading with the supply. All of them happen on your own turn.

The board has nine ports: four 3:1 ports and five 2:1 ports, one for each resource.

What does a 4:1 trade really cost?

You hand over 4 cards and get 1 back. That is 3 cards gone for good.

Three cards may not sound like much, so put it in pips. From Lesson 6, a settlement on 11 pips collects about 11 cards every 36 rolls. To earn 4 cards, it needs about 13 rolls. In a four-player game, that is more than three full trips around the table.

So one careless 4:1 trade can throw away three rounds of your best settlement’s work. Do it every turn, and you are playing with one settlement fewer than everyone else.

When is a 4:1 trade the right call?

A 4:1 trade is fine, even smart, in a few situations.

• It finishes a build this turn. You are one brick short of a settlement and holding 4 wool. Trade and build. A settlement is a point plus income for the rest of the game. That is worth far more than 3 spare cards.
• Nobody will trade with you. You asked the table. No one has what you need, or the only offer comes from the leader. The bank does not care who is winning, and it never gets stronger from your trade.
• It wins the game. If a 4:1 trade gets you to 10 points this turn, make it. Nothing else matters.
• The cards are truly dead. Late in the game, with no open spots and no plan for Longest Route, a stack of brick may never be useful again. Turning dead cards into ore is fine, especially if it sets up a city soon.

When does a bank trade become a leak?

Here are the habits that quietly cost games.

• Trading to “save up.” You trade 4:1 now for a card you plan to use next turn. Then someone rolls a 7, the robber steals from you, or your plan changes. You paid 3 cards to hold 1.
• Dodging the 7 with no build. Holding 8 or more cards is risky, as Lesson 4 showed. But in a four-player game, three other players roll before your next turn. The chance of at least one 7 among those rolls is a little over 40 percent. A 4:1 trade costs you 3 cards every time. On its own, the trade often costs more than the risk.
• Forgetting your port. If you own a 3:1 port, every 4:1 trade throws away a card. Check your coast before you trade.
• Skipping the table. A player might give you 1 for 1, or 1 for 2. Always ask the table first, unless the only taker is the leader.
• Patching a broken income. If you are making a 4:1 trade every turn for the same resource, the problem is not the trade. It is your board position. Your next settlement should fix it, or reach a port that does.

When is a port worth building toward?

A port is only as good as the cards you feed it. Compare what 10 cards of one resource become at each rate:

A 3:1 port helps a little with everything. It is a good fit if your income is lopsided and you trade with the supply often.

A 2:1 port is a big deal, but only for its own resource. Say you have settlements on a 6 wheat field and an 8 wheat field. That is 10 wheat pips, about 10 wheat every 36 rolls. With the 2:1 wheat port, those become about 5 cards of anything you want. Now your wheat is every resource at once.

Without strong production, though, a 2:1 port does very little. A wool port next to a single 3-pip pasture will rarely get used.

Ports sit on the coast, and coastal corners touch fewer hexes, so a port settlement usually collects less. That is the trade-off. Most players reach a port with their third or fourth settlement, once they know which resource they make the most of.

How do you decide in the moment?

Before any trade with the supply, ask two questions.

1. Does this trade let me build something this turn? If yes, make the trade and build.
2. If not, can I wait? Usually, yes. Keep your cards, ask the table next turn, and let your income catch up.

The exceptions are rare: a trade that wins the game, or truly dead cards late. Everything else can wait a turn.

For more on trading with other players without feeding the leader, see our guide on how to win at Catan.

Try it this week

Your drill is simple and strict: no 4:1 trades unless they build something that turn.

1. Say the rule before the game. Out loud or in your head: “No 4:1 unless I build this turn.”
2. Name the build first. Each time you reach for the bank, say what you are about to build. If you cannot name it, keep your cards.
3. Check your ports. Before any supply trade, look at your settlements on the coast. Use the best rate you own.
4. Ask the table first. Offer a player trade before every bank trade, and note who says yes.
5. Keep a tally. On a scrap of paper, mark each 4:1 you made and each one you skipped. After the game, look back. Did any skipped trade really cost you? Most of the time, the answer is no.