Catan Glossary — Definitions of Terms, Rules, and Mechanics

A

Active player: The player whose turn it currently is. In base Catan, only the active player may trade with others, build, and roll dice. In the 5–6 expansion, non-active players may also build during the active player's end-of-turn build phase but may not trade.
Adjacency (number-token): Two hexes touching at an edge are adjacent. The generator's "no-adjacent-reds" constraint prevents 6 and 8 tokens from sharing an edge — by default, no high-probability tile is next to another.
Aqueduct: A Cities & Knights science-track level-3 improvement: on any production roll that yields you no resources, you may take one resource of your choice from the supply. Sharply reduces production variance.

B

Barbarian ship: Cities & Knights component. A token on a seven-space track that advances toward Catan each time a 7 is rolled. When it arrives, all active knights tally strength against city count for a defence check.
Bishop card: A Cities & Knights progress card (politics track) that moves the robber. Functionally similar to a base-game Soldier but doesn't count toward Largest Army.
Bridge: A Traders & Barbarians "Rivers of Catan" road piece spanning a river hex edge. Costs 1 wood + 1 brick, earns the builder 1 gold coin upon placement. Counts as a road segment for longest-trade-route purposes.
Build phase: The 5–6 expansion rule: after the active player ends their turn, every other player may build (roads, settlements, cities, knights, walls, improvements) and play one development/progress card before the next active turn begins. No trading allowed.

C

Caravans (scenario): One of the five Traders & Barbarians scenarios. The desert becomes an oasis with two desert cities; players move camel pieces between settlements and oases for VP and resource bonuses.
City: Upgraded settlement. Produces 2 resources per adjacent activated hex (vs. 1 for a settlement). Costs 2 wheat + 3 ore to upgrade from a settlement. Worth 2 VP. In Cities & Knights, upgraded cities also produce commodities on forest/pasture/mountain hexes.
City wall: A Cities & Knights component. Costs 2 brick. Raises the holder's hand-size limit by 2 (max 13 with three walls), reducing the impact of 7-roll discards. Does not affect barbarian-attack defence.
Commodities: Cities & Knights' second resource tier: paper (from upgraded forest cities), cloth (upgraded pasture), coin (upgraded mountain). Spent on city improvements; tradeable like resources.
Constraint solver: Common name for the algorithmic component of a balanced board generator. The solver places terrain and number tokens such that all enabled rules (no-adjacent-reds, terrain diversification, etc.) are satisfied simultaneously.

D

Defender of Catan: A Cities & Knights VP card awarded after a successful barbarian repulsion to the player whose single greatest knight-strength contribution exceeded all others. Ties produce no award.
Desert: A non-producing hex. The robber starts on the desert. Settlements adjacent to a desert produce nothing from that hex but still produce from their other two adjacent hexes. The 5–6 board has two deserts; Seafarers and base Catan have one.
Development card: A purchased card from the base-game deck. Costs 1 sheep + 1 wheat + 1 ore. Types: Knight (move the robber, counts toward Largest Army), Road Building (build 2 free roads), Year of Plenty (take 2 resources from the bank), Monopoly (claim all of a named resource from opponents), Victory Point (hidden 1 VP, revealed only at game end).
Diplomat: A Cities & Knights politics-track progress card. Removes an opponent's open road segment (a segment not directly connecting two of their own buildings). The opponent doesn't recover the road resources; you may then build a road of your own in the freed slot.
Discovery island: A Seafarers component. A small landmass separate from the main island, settleable via ships. Settling on a discovery island for the first time earns a bonus VP per scenario rules.

E

Endgame: The phase of a Catan game where one player approaches the victory threshold. Endgame in base Catan typically starts around 7–8 VP; in Cities & Knights around 10–11. Distinguished by defensive plays (robber/pirate placement, longest-road/army theft attempts) becoming more common than expansion plays.
Engineer: A Cities & Knights trade-track progress card. Lets you build a city wall for free (no brick cost).
Event card variant: A Traders & Barbarians short variant that replaces dice rolls with a 36-card event deck. Each card resolves the same as a specific dice outcome but in a fixed distribution, reducing roll variance.
Expected rolls (per 36 turns): A statistical measure used in probability analysis. A token rolls its expected count out of 36 turns based on its pip value: 6 and 8 are expected 5 times, 5 and 9 four times, 4 and 10 three times, 3 and 11 twice, 2 and 12 once.

F

Fishermen of Catan: A Traders & Barbarians scenario where fishing-ground tiles attach to coastal intersections, producing fish tiles on relevant dice rolls. Fish are spent for resources, robber movement, or progress.
Friendly Robber: A Traders & Barbarians short variant: the robber cannot be placed on a hex adjacent to a player with ≤2 VP. Reduces "pick on the leader" pressure on new players.

G

Generic port (3:1): A coastal port that lets a settled-adjacent player trade any 3 identical resources for 1 resource of choice. Marked with a generic anchor symbol. Six exist on the 19-hex base board; nine on the 30-hex 5–6 board.
Gold field: A Seafarers terrain. When activated, the player receives 1 resource of their choice (or 2 for a city). Functionally a wild resource hex; high-pip gold-fields are among the strongest tiles in the game.
Gold coin (T&B): A Rivers of Catan currency earned by building bridges. Convert to VP at game end (2 coins = 1 VP, rounded down). Cannot be spent during the game.

H

Hand-size limit: The maximum number of resource and commodity cards a player may hold without being subject to 7-roll discards. Default is 7; city walls raise it by 2 each (max 13).
Harbor Masters: A Traders & Barbarians short variant: extra VP for owning ports of multiple types. Encourages port-targeting strategies.
Heading for New Shores: The introductory Seafarers scenario: a main island with two or three discovery islands. The layout this site's Seafarers generator emulates.
Hex: A six-sided tile representing a single terrain type. The base Catan board has 19 hexes; the 5–6 expansion 30; Seafarers and its variants 20+ depending on scenario.

I

Improvement (city): In Cities & Knights, a track-based upgrade purchased with commodities. Three tracks (politics, trade, science), five levels each. Each level grants an ability; reaching level 4 in a track lets you build a metropolis worth 2 extra VP.
Inactive knight: A Cities & Knights knight piece that has not been activated. Cannot defend, chase the robber, or contribute to the barbarian-defence tally until activated with 1 wheat.
Initial placement: The two-pass setup at the start of every Catan game: in turn order, each player places one settlement and one road; then in reverse turn order, each player places a second settlement and road. The second settlement's adjacent hexes also yield starting resources.

K

Knight (development card): A base-game development card. When played, the holder moves the robber to a new hex and steals one resource from a player adjacent to that hex. Each played Knight counts toward Largest Army (≥3 to claim the 2-VP bonus).
Knight (Cities & Knights piece): A physical knight piece built on an intersection adjacent to your road network. Costs 1 sheep + 1 ore. Must be activated with 1 wheat to defend, chase the robber, or contribute to barbarian defence. Three strength tiers: basic (1), strong (2), mighty (3).

L

Largest Army: A base-game bonus: the first player to play 3 Knight development cards earns the 2-VP Largest Army card. Transferred when another player strictly exceeds the holder's count.
Longest Road: A base-game bonus: the first player to build an unbroken chain of 5 or more road segments earns the 2-VP Longest Road card. Transferred when another player strictly exceeds the current holder's length. Broken chains lose the bonus; ties retain it.
Longest Trade Route: The Seafarers equivalent of Longest Road. Counts roads and ships as a continuous route. Same length and transfer rules as Longest Road.

M

Metropolis: A Cities & Knights upgraded city (flipped from a regular city). Worth 2 extra VP, immune to barbarian attack. One metropolis per improvement track may exist; transfers to the player who strictly exceeds the current holder's track level.
Mighty knight: A Cities & Knights knight at strength 3 — the highest tier. Promotion from strong to mighty costs 1 sheep + 1 ore and requires the politics-track improvement that unlocks mighty knights.
Monopoly card: A base-game development card. When played, the holder names a resource type and takes all instances of that resource from every other player.

N

Number token: A circular chip placed on a non-desert hex showing 2–12 (excluding 7). The chip indicates the dice roll that activates the hex's production. The 6 and 8 chips are marked in red and have pip-values of 5 each (the highest).

O

Oasis: A Traders & Barbarians "Caravans" scenario component that replaces the desert. Houses two desert cities — destinations for camel caravans. Not the robber's starting hex in this scenario.
Old boot (fish tile): A Fishermen of Catan fish-bag token. When drawn, the player gives the old boot to the current leader (or active player's choice among tied leaders). Acts as a small catch-up mechanic.

P

Pip value: The number of dots printed under each number token, indicating its rolling probability. 6 and 8 = 5 pips; 5 and 9 = 4 pips; 4 and 10 = 3 pips; 3 and 11 = 2 pips; 2 and 12 = 1 pip. A settlement's total pips across adjacent hexes is the standard metric of opening strength.
Pirate: The Seafarers sea-going analogue of the robber. Disables ships adjacent to it and allows card-stealing from players whose ships or coastal settlements neighbour the pirate's hex.
Pirate Islands (scenario): A Seafarers scenario where a pirate fortress sits in the middle of the sea and players race to defeat it for victory points. More combat-oriented than other Seafarers scenarios.
Progress card: A Cities & Knights card type (politics, trade, science decks) drawn when specific improvement levels or production rolls trigger. Replaces base Catan's development cards in C&K scenarios.

Q

Queue (build phase): The implicit ordering during the 5–6 expansion's build phase: every non-active player builds in turn order before the next active player begins. In a six-player game, five build phases run between each pair of consecutive active turns.

R

Red number: A number token marked in red — specifically 6 or 8, the two highest-probability rolls (5/36 each). The official rule "no adjacent reds" prevents two red tokens from sharing an edge, ensuring no settlement spot has access to two of the highest-probability hexes.
Resource: A card of one of five types: wood (forest), brick (hills), wheat (fields), sheep (pasture), ore (mountains). Earned when a settlement or city's adjacent hex is activated by a dice roll. Spent on building, trading, and development cards.
Resource-specific port (2:1): A coastal port that lets a settled-adjacent player trade 2 of one specific resource for 1 resource of choice. Five exist on the 19-hex board (one per resource); five more in the 5–6 expansion.
Rivers of Catan: A Traders & Barbarians scenario where three river hexes replace land hexes. Building a bridge across a river earns gold coins, which convert to VP at game end.
Road: A base-game building piece placed on a hex edge. Costs 1 wood + 1 brick. Each player has 15 roads. Roads must connect to your settlements/cities or to other roads of yours. Five or more unbroken roads earn the Longest Road bonus.
Road Building card: A base-game development card. When played, the holder builds 2 free roads anywhere their network allows.
Robber: A pawn-like piece that starts on the desert. Moved by 7-rolls or Knight cards. Blocks production on its hex; the moving player may steal a random card from a player adjacent to the new hex.

S

Seed (board URL): A short string in the URL of a generated board (e.g., /board/abc123def). The seed deterministically produces the same board layout every time it's loaded — the share mechanism for this site's generator.
Settlement: A base-game building piece placed on a road intersection. Costs 1 wood + 1 brick + 1 wheat + 1 sheep. Each player has 5 settlements. Produces 1 resource per adjacent activated hex. Worth 1 VP. Upgradeable to a city.
Seven roll: A dice roll of 7. Triggers: (1) every player with >7 cards discards half (rounded down); (2) the active player moves the robber and steals a card; in C&K, the barbarian ship advances instead of the standard rob.
Ship: A Seafarers piece built on a sea-edge. Costs 1 wood + 1 sheep. Each player has 15 ships. Connects to settlements/cities and other ships. Can be moved once per turn (open ships only). Counts toward Longest Trade Route.
Strong knight: A Cities & Knights knight at strength 2 — the middle tier. Promotion from basic costs 1 sheep + 1 ore.

T

Trade phase: The portion of the active player's turn between dice roll and building. Open to player-to-player trading and maritime (port/4:1) trading.
Tournament rules: Commonly: no-adjacent-reds enforced, no-adjacent-2s-or-12s enforced, no same-number adjacency, resource diversification across corners. The default constraint set in this site's generator.
Two-pass setup: See Initial placement. The standard Catan setup procedure.

V

Victory Point (VP): The win condition currency. Sources: 1 VP per settlement, 2 VP per city, 2 VP for Longest Road, 2 VP for Largest Army, 1 VP per Victory Point development/progress card, and 2 VP per metropolis (C&K). Threshold: 10 VP base, 13 VP in C&K, varies in Seafarers and T&B scenarios.
Victory Point card (hidden): A development card (or progress card in C&K) worth 1 VP. Held face-down in hand until the final reveal — opponents can't count it toward your visible VP total, which lets winning declarations come as a surprise.

Y

Year of Plenty: A base-game development card. When played, the holder takes 2 resources of any type from the bank, free.
Year-of-Plenty lock: A common endgame play: holding a Year of Plenty card until the moment it can be combined with on-hand resources to build the final settlement, city, or development card that pushes the holder past the victory threshold — typically at 8 VP, locking in the win the same turn.