Catan rules
The robber, trading, longest road and the rules people quietly get wrong.
The base game, third and fourth editions. Expansion rules are noted where they differ.
Rolling a seven and the robber
On a seven, three things happen in order.
- Every player holding more than seven resource cards discards half, rounded down. Eight cards means discarding four.
- The player who rolled moves the robber to any other land hex, or the desert. It may not stay where it is.
- They then steal one random card from any single player with a settlement or city touching that hex.
A hex with the robber on it produces nothing for anyone until the robber moves.
Trading
You may trade only on your own turn, and only after you have rolled. Players may trade any resources at any ratio they can agree, but never a promise, a development card or a future favour: only cards on the table now.
With the bank, four of one resource buys any one. A general port makes it three to one, and a special port makes it two to one for that resource only.
Two players may not trade with each other through you, and the active player must be part of every trade.
Longest road
Worth 2 victory points, and it goes to the first player to build a continuous road of five or more segments. Someone else takes it only by building a strictly longer one.
Placing a settlement on an opponent’s road breaks it at that point. If a break leaves nobody with five, the card goes back to the box until someone qualifies again. If a break creates a tie, the card stays with whoever holds it.
Largest army
Worth 2 victory points. Play three knight cards and take it. Another player needs a strictly greater number, so four, to take it from you. Knights already played stay played.
What everything costs
- Road — brick and lumber.
- Settlement — brick, lumber, wool and grain.
- City — three ore and two grain, replacing one of your settlements.
- Development card — ore, wool and grain.
Settlements must be at least two roads apart from any other settlement or city, yours included.
Winning
Ten victory points wins, and you may only declare it on your own turn. Victory point development cards stay hidden until you win with them, which is how a player on eight visible points suddenly finishes.
Questions
Do I discard on a seven if I have exactly seven cards?
No. Only players with eight or more discard, and they discard half rounded down.
Can I trade on someone else’s turn?
No. All trading happens on the active player’s turn, and they must be one of the two parties.
Can a settlement break a longest road?
Yes, and it is one of the strongest defensive moves in the game.