Catan development cards: the exact odds, and when to buy one
The Catan development deck has 25 cards: 14 knights, 5 victory points and 2 each of Road Building, Year of Plenty and Monopoly. Each card you buy is a knight 56% of the time and a victory point 20% of the time. You need 5.2 cards on average to draw the 3 knights Largest Army takes, and 5 buys give a 70.8% chance of at least one point card.
What is in the Catan development deck
A development card costs one ore, one wool and one grain. You draw it blind, keep it hidden, and may play one per turn, but never on the turn you bought it (victory points excepted: they count the moment you can win with them).
| Card | In the deck | Chance on one draw | What it does |
|---|---|---|---|
| Knight | 14 | 56% | Move the robber and steal a card; counts toward Largest Army |
| Victory point | 5 | 20% | One hidden point |
| Road Building | 2 | 8% | Build two roads free |
| Year of Plenty | 2 | 8% | Take any two resources from the bank |
| Monopoly | 2 | 8% | Name a resource; every player gives you all of theirs |
The 5–6 player extension adds 9 cards: 6 more knights and one more of each progress card, for 34.
The odds of each card, buy by buy
These are exact odds for the cards you draw. They hold mid-game too: cards other players bought are unseen, so they don’t change your chances.
| Cards bought | At least one victory point | Knights expected | 3+ knights (Largest Army) | At least one Monopoly |
|---|---|---|---|---|
| 1 | 20.0% | 0.56 | 0.0% | 8.0% |
| 2 | 36.7% | 1.12 | 0.0% | 15.7% |
| 3 | 50.4% | 1.68 | 15.8% | 23.0% |
| 4 | 61.7% | 2.24 | 39.6% | 30.0% |
| 5 | 70.8% | 2.8 | 62.2% | 36.7% |
| 6 | 78.1% | 3.36 | 79.1% | 43.0% |
| 8 | 88.4% | 4.48 | 95.7% | 54.7% |
| 10 | 94.3% | 5.6 | 99.5% | 65.0% |
Two numbers to remember. Three cards are a coin flip for a victory point (50.4%). And Largest Army needs about five cards: 5.2 on average, with a 62.2% chance after five and 79.1% after six.
How many knights for Largest Army?
Largest Army goes to the first player to play 3 knights, and moves to anyone who later plays more. It is worth 2 points. Because 14 of the 25 cards are knights, an army costs about five cards, or 15 resources of ore, wool and grain, and it can be taken from you.
That price is why Largest Army is usually a side effect, not a plan. A player on ore and grain buys cards anyway, plays knights to move the robber off their own hexes, and the army arrives.
When to buy a development card
- Buy when you can’t build anything better. A city costs 5 cards for one sure point. A development card costs 3 for 0.2 points on average plus a knight more than half the time.
- Buy when you are holding too many cards. Spending ore, wool and grain before a 7 hits is often the best use of them.
- Buy when you are on ore, wool and grain anyway. Those are the city and card resources; wood and brick players build roads instead.
- Buy late to hide your score. Victory point cards stay hidden, so a player on 8 with two unknown cards might be on 10.
- Hold a knight for the turn the robber lands on your best hex. You may play it before you roll.
Our bots back the first point up. In 5,000 four-player games they bought few cards, 1.5 a game between all four, and mostly when they were already ahead: seats that bought 3 or 4 cards won 38.4% of games, against 23.4% for seats that bought none. That is cards following a strong economy, not cards making one.
How to play the progress cards
Monopoly is strongest when everyone has just been paid one resource, for example after a run of 8s on the only wheat hex, or when you hold a 2:1 harbor for that resource. Road Building wins Longest Road races and grabs a contested corner. Year of Plenty finishes a city or a settlement on the turn you need it, so keep it for the missing piece rather than playing it early.
Questions people ask
How many development cards are in Catan?
25 in the base game: 14 knights, 5 victory points, and 2 each of Road Building, Year of Plenty and Monopoly. The 5–6 player extension adds 9 more.
How many knights are in Catan?
14 of the 25 development cards are knights, so each card you buy is a knight 56% of the time.
How many development cards do you need for Largest Army?
About 5. Largest Army needs 3 knights played, and with 14 knights in 25 cards that takes 5.2 buys on average, with a 62.2% chance after five.
What are the odds of a victory point card in Catan?
20% on each draw. After 3 cards the chance of at least one point is 50.4%, after 5 it is 70.8%.
Can you play a development card the turn you buy it?
No, except a victory point card when it gives you the winning tenth point. You may play one card per turn, even before you roll.
Are development cards worth it in Catan?
When you can’t build a city or settlement, yes. A card costs 3 resources for about a fifth of a point plus a likely knight; a city costs 5 for a sure point.
Sources
Odds computed from the deck’s published contents on 19 October 2026; bot figures from our own 5,000-game simulation.
Keep reading
How to win at Catan-style games: a strategy guide
Catan rules people get wrong
We simulated 10,000 games of Catan
Test your timing against the bots
Hearthsea is free: every mode and every island, bots, online rooms with friends and quick match, with no daily limit. Every card comes from the same 25-card deck as the board game.
Hearthsea is free: every mode and every island, bots, online rooms with friends and quick match, with no daily limit. Every card comes from the same 25-card deck as the board game.
CATAN is a registered trademark of Catan GmbH. Hearthsea is an independent game and is not affiliated with, endorsed by or sponsored by Catan GmbH or its publishers. Other game names belong to their owners and are used here only to describe and compare.