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"Sunless Sea" Walkthrough: Terror and Nightmares

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Defeat Terror and avoid Nightmares in "Sunless Sea" with this detailed guide. "Sunless Sea" is owned by Failbetter Games. Images are used for educational purposes only.

Defeat Terror and avoid Nightmares in "Sunless Sea" with this detailed guide. "Sunless Sea" is owned by Failbetter Games. Images are used for educational purposes only.

How to Fight Terror in Sunless Sea

The Unterzee is a terrifying place. The incomprehensible blackness of its depths would get to even the most hardened of zailors eventually, no matter how long they've spent zailing. This pressure can be alleviated, of course—but with time, with horrors, with bad experiences piled on bad experiences, the Terror will eventually consume anyone.

Terror is a mechanic in Sunless Sea. In a way, it's your ultimate enemy while navigating the black of the Neath. Learn to fight it, and you'll find the game a lot easier. Fail ... well, if you fail, then you'll have to fight off Nightmares instead.

Who Is Terror?

Terror is one of Sunless Sea's most important mechanics and is displayed in the top-left corner of the screen, beneath Fuel and Hunger. It measures the stress level of your Crew. At zero, you and your men/women are at absolute peace; at 100, you are facing open mutiny. In most cases, reaching 100 will prove to be the end of the game. More on that shortly.

How to Accrue Terror

  • Zailing in the black. If you guide your ship into patches of blackened, unlit water, a small, brown counter will appear on the Terror icon. When it reaches ten dots, you'll gain another point of Terror. If you manage to hit a lit spot or a shoreline before the brown dots reach ten, they'll turn green and begin to backtrack.
  • Events. Many events throughout the game will add Terror to your counter. Most of the time, you'll gain Terror by failing events, while in other cases, you'll gain Terror by succeeding.
  • Locations. Visiting some places simply go over well with your Crew. For example, revisiting Hunter's Keep after completing its storyline will add Terror to your counter and little else.
  • Combat. Some creatures can use the Appalling Cry move. This will inflict small amounts of Terror damage.

Fortunately, there are just as many ways to counter the flow of Terror ... though they're slightly less omnipresent and typically more difficult to achieve.

The player visits Giannotti Harbour in "Sunless Sea."

The player visits Giannotti Harbour in "Sunless Sea."

Removing Terror

As noted above, you can dispel impending Terror while sailing by moving into a lit spot. But how can you fight Terror otherwise—or perhaps even reduce your counter? Here are a few suggestions.

  • Plot your courses carefully. Generally speaking, Terror will not accrue if you're sailing close to shore. This isn't true of all land formations on the Unterzee, but most of the time it's best to take a course that will keep you within sight of land. For example, rather than taking a direct course north from Fallen London to Venderbight, you should stick to the western coastline and follow it until you hit the Tomb Colonies. You'll use up more Fuel this way, but it's much easier to get Fuel than it is to remove Terror.
  • Worried you'll stray into deep water accidentally? Watch your ship. If you're in an area that accrues Terror, a green light will surround your vessel. Otherwise, it's a healthier colour.
  • Always sail with a large enough Crew to keep your engines at 100% efficiency. If you don't have at least half your full Crew complement, you'll lose speed. Not so bad if you stick near the shore, but if you need to slink through darkened waters ... needless to say, Terror accumulation doesn't slow down with your boat.
  • Don't participate in questionable activities. Many events that sound bad probably are bad, especially if you fail on challenges. You should also make a point not to repeat events that only raise your Terror over and over, particularly if they don't give you anything in return. (Duh.) In this vein, you really don't want to do anything that will irritate the gods, as this tends to terrify the heck out of your Crew.
  • Kill certain monsters. The Bat-Swarms that wander between Fallen London and Venderbight can be thrown overboard upon defeat, and doing so will remove between one and five Terror. Not great, but they're plentiful and easy to kill, sooo ...
  • Visit pubs. This isn't universal to every port, but in most places, you can pay a bit of money to drop your Terror while in port. Be wary of the costs! Where this is relatively cheap and useful in some places (Fallen London), it's very costly and somewhat useless in others (Venderbight).
  • Allow for activities that boost morale. Occasionally your Crew will ask to put on shows, plays, contests, and the like. Indulge them, and you'll typically see a drop in Terror.
  • Go to the Surface. If you head far south of London, following the shoreline, you'll eventually come to the Cumaean Canal Staging Area. Do so with a large amount of Fuel (30ish is safest) and a reasonable amount of Supplies (10+), and you can head aboveground to Naples. Naples is easily the best place to reduce your Terror in the game, though the cost of Fuel is high enough to make it a last-ditch resort for wealthy travellers. You also risk losing Crew up here, and you won't be able to replace them with guys from Naples.
  • Return to London. Every time you return to London, assuming your Terror has risen above 50, you'll drop back down to 50 automatically. This isn't the best way to manage your Terror, though, because coming back with a Terror count above 50 has ... repercussions.
The player has Recurring Nightmares after accumulating too much Terror in "Sunless Sea."

The player has Recurring Nightmares after accumulating too much Terror in "Sunless Sea."


The first time you return to Fallen London with more than 50 Terror, you'll have a Nightmare. From that point on, you'll gain the Nightmare's Strength story, noted in your Journal. Continue to return to Fallen London above 50, and Nightmare's Strength will increase, gaining even greater strength if you return with 70 or more Terror.

What does this mean? It means that you have the eye of some eldritch horror. No, no, the Eye, rather. Something is watching you, and occasionally while you're at sea, it will plague you with the event A Recurring Nightmare. In this event, you can attempt to challenge or flee from the Eye. Failing will inflict more Terror damage, as well as increase the Nightmare's Strength. Failing when challenging the Eye will increase your Terror by near-ridiculous amounts (50!) and is not recommended unless you have an insane hearts score.

What can you do about Nightmares? The best course is simply to avoid them altogether. Don't come back to Fallen London unless your Terror is below 50. Failing that, you can mitigate the effects of the Nightmare by getting a Restful Night in your Lodgings consistently. But be warned—you need to be very persistent in not returning to London with high Terror and in sleeping properly to shake off the Nightmare. Sleep well.