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Underwater Cities
#53BGG8.0RATING
Updated Sep 12
1–4
PLAYERS
80–150
MINUTES
2
BEST WITH
3.6
HEAVY
ERRATA3
Rulebook p.9 final-scoring example shows the wrong carddesigner
- RULING
- "Yes, it's a bad card. We'll change it." The card pictured in the final-scoring example on rulebook page 9 shows science instead of steelplast; the printed example is wrong. The rule itself is unchanged: the card lets you spend any number of kelp + steelplast pairs for an equal number of points.
Rulebook p.11 Brown Metropolis Special Cards description is wrongcommunity high-engagementdesigner
- RULING
- The correct text is: "At the end of the game, score 2 points for each Special card you played and paid for. This includes not only your claimed Special cards, but also those with instant effects. Discarded Special Cards (Instant Effect and Action Cards) are placed under the player board and count 2 points."
AUTHOR: UtterMarcus (thread compiler), sourced from sucd (Vladimír Suchý, designer)SOURCE: boardgamegeek.com(25 replies)DATE: 2019-04-13Production symbol on the "Trial Run" card is a printing inconsistencydesigner
- RULING
- The gear (production) symbol on this card marks that the yield shown equals a production yield; it should either appear on all such cards or on none, and its presence here is inconsistent. The card is used normally when you play it, not during the production phase.
DESIGNER CLARIFICATIONS14
A specified card cost replaces the normal build costdesigner
- CONTEXT
- A card reading "pay 1 steelplast → build a desalination plant" was read by some players as paying the steelplast *in addition to* the plant's usual cost.
- RULING
- "I will pay steelplast and build the desalination plant. I will not pay anything else."
A Special card discarded for the 4-card limit goes under your player boarddesigner
- CONTEXT
- A player at the 4 Action-card limit gives up an available Special card in order to claim a new one — does it go to the bottom of the Special deck, or under the player board?
- RULING
- "I would apply the rule: place under the board. The card will bring you 2 points with the right metropolis."
Card 66 is not multiplied by a x3 tunneldesigner
- RULING
- "For me, it means the effect works only for 1 credit, 1 varech and 1 science, otherwise, the infinity sign would be present. This is correct. Just one."
Card 124 "Demonstration" costs 1 credit total, not 1 per carddesigner
- CONTEXT
- The card text reads "You may pay 1 credit to use one or two of your action cards", but the iconography suggests 1 credit per action card used. The designer confirmed the reading "Up to two, for just one credit."
- RULING
- "correctly" — one credit total lets you use one or two of your Action cards. The card text is authoritative; the iconography is misleading.
Biomatter cannot pay surchargesdesigner
- CONTEXT
- Biomatter substitutes for kelp or steelplast when building a tunnel, building or city. Players asked whether it also covers surcharges.
- RULING
- "I can't use a biomater for surcharges."
Card 98 raises the hand limit you must discard down todesigner
- CONTEXT
- Rulebook p.16 tells you to keep 3 cards at the end of an era; a card that raises your hand limit appears to contradict it.
- RULING
- "Compare yellow text. Page 16. UNDERSEA SERVER FARM 'You must discard down to 3 cards at the beginning of your turn and at the beginning of each era. At any other time, it is okay to have more than 3. If a card increases your hand limit by one, then you must discard down to 4 cards at the beginning of your turn and at the beginning of each era.'"
Production from three or more upgraded farms in one citydesigner
- CONTEXT
- The rulebook covers a pair of matching upgraded buildings in a city, but not a third or fourth.
- RULING
- "example: 3 upgraded farms in one city: (3 kelp + 3 VPs) + (1 kelp + 1vp) 4 upgraded farms in one city 6 kelp + 6 VP". Building more than two farms in one city is disadvantageous.
"Build a structure, then upgrade it" is one indivisible actiondesigner
- RULING
- "this is one action. I have to build a structure and immediately upgrade it. you can not just build a structure or can not just upgrade it."
Brown metropolis scores tunnels connected to the networkdesigner
- CONTEXT
- The tile text ("tunnels connected to cities") left players unsure whether every tunnel traced back to the starting city counts.
- RULING
- "correct interpretation: connected to the network"
The Always Available slot can be used several times per rounddesigner
- RULING
- "Yes, it is possible. You can use this slot several times per round." It is available to every player, including one who has already used it this round.
The Always Available slot costs exactly one carddesigner
- CONTEXT
- Players were unsure whether the card you discard as the slot's cost is in addition to some other card.
- RULING
- "You give one card. No second card."
Pay-for-benefit card effects apply only oncepublisher
- CONTEXT
- Card 44 (Black Market) converts steelplast into biomatter; players asked whether the conversion could be repeated.
- RULING
- "Rules page 19: PAY: Many cards allow you to pay a cost to get a benefit. As you would expect, if you can't pay the cost, you do not get the benefit (however, you may play the card with no effect). If not otherwise specified, you pay the cost and gain the benefit only once. Cards that allow you to pay more to gain more will say so."
AUTHOR: polanek (Katerina Sucha, publisher — Delicious Games)SOURCE: boardgamegeek.com(3 replies)DATE: 2018-11-12On "build and upgrade" cards the printed cost already covers the upgradedesigner
- CONTEXT
- Cards 135 and 141 read "pay X to build a structure, then upgrade it" — players asked whether the usual 1 science upgrade cost is added.
- RULING
- "card 141: all the cost of purchasing an upgraded farm is 1 biomass; card 135: all the cost of purchasing an upgraded tunel is 1 credit and 1 science." Asked directly whether the initial cost already covers the upgrade, the designer answered "YES".
Government Contracts #3–#5 give the building for freedesigner
- RULING
- "It is built for free." You also receive the resource shown and the points: "For example, on Contract 3 you build a farm free and you will receive a kelp and 3 points."
Q&A2
Card 171 "Pay 3 steelplast to build a city"community high-engagement
- QUESTION
- Does the 3 steelplast replace the city's normal cost, and can the city be symbiotic?
- ANSWER
- The 3 steelplast is the entire cost — rules page 19 states that when a card specifies a cost, you pay the specified cost instead of the usual one. Because the card says "a city" without qualification, it may be either a non-symbiotic or a symbiotic city. The effect applies once.
Can you discard the newly claimed Action card to stay at four?community high-engagement
- QUESTION
- With four Action cards already claimed, can the fifth card be discarded — and used as it is discarded — in order to claim it?
- ANSWER
- No. Per rules page 8 the discard happens before you claim the new card, so the card you are about to claim can never be the one you discard. You may discard any of the four you already hold, but you cannot use a card you have not claimed.
EDGE CASES1
City placement versus network connectioncommunity high-engagement
- SITUATION
- Players conflate two separate requirements — where a city or tunnel may legally be placed, and when it starts producing.
- RULING
- A tunnel may only be built if a line of tunnels traces back to your Starting City, so every tunnel is connected by definition. A city may be built on any site adjacent to a previously built city; that earlier city does not need to be connected to your network. Cities, their buildings and metropolises only become connected — and only then produce — once a chain of tunnels links them back to your Starting City.
Last researched: 2026-08-09
CATEGORIES
Card Game·City Building·Industry / Manufacturing·Nautical·Science Fiction
MECHANICS
End Game BonusesHand ManagementIncomeNetwork and Route BuildingSolo / Solitaire GameTurn Order: Claim ActionTurn Order: Stat-BasedWorker Placement
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An opponent's settlement blocks your road network — your road cannot be built through or past an occupied intersection.
◆ Catan — Roads & Building, p. 7
At the end of each round, the player with the most of the goal trait scores points equal to their amount; the player with the second most scores fewer.
◆ Wingspan — End of Round, p. 11
Null cards deal 0 damage regardless of base value or any bonuses applied.
◆ Gloomhaven — Attack Modifier Deck, p. 23
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