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MAGELLAN and the Stuttering Bug

Shortly after Sunless Sea launched, some players reported experiencing a frame rate or stuttering issue. Now we’ve identified and fixed the cause, we wanted to explain what happened.

First, a big thank you to everyone who submitted bug reports on this issue and worked with us to resolve it. We could not have done this nearly as quickly without you. We’ve been listening in on forum discussions about the symptoms and possible causes of the problem, and they also helped us us get to the root of the issue faster than we could have otherwise. Cheers to the finest game community on the internet!

You may know that Sunless Sea is partly built around the same technology as Fallen London. This is a quality-based narrative system, where you qualify for certain stories based on the qualities you possess.

That’s great, because it's a robust, stable system that we have been working with for five years. It gave us a big head-start when creating Sunless Sea, and provided tools that our writers and artist were already used to working with.

In Fallen London, the system checks qualities whenever the player performs an action. However, in Sunless Sea you’re constantly on the move, so the system performs the same check every second - enabling us to present players with stories based on moment-to-moment changes. As a result, the game would sometimes stutter over frames while players’ machines were struggling to perform the checks.

During Early Access, we didn't encounter the frame rate bug frequently enough to identify it. There were fewer qualities in the game overall, and fewer players had reached the late game.

To fix the issue, we've made some changes to the way Sunless Sea deals with the quality-based narrative system. To use a convenient metaphor: before, the game was going through the whole book to find a single word. Now, we’ve added an index.

Initial feedback from our testers has been very positive. It took a bit longer than expected for this patch to be completed; this was a change to an essential part of the core codebase, so we wanted to make sure it was as well optimised and stable as possible.

As ever, if you experience any issues, we feast hungrily upon bug reports that are sent to

Magellan v1.02 Patch Notes

New feature

  • There are now some variations on the way victory screens look based on the win condition you achieved. We will be adding more to the game soon.
Bug fixes

  • The periodic frame rate drop/stuttering issue has been fixed.
  • A few edge cases that were occasionally preventing people from carrying forward their legacy items after exiting the game have been resolved.
  • Mt Nomad and the Tree of Ages will now spawn more often.
  • Some edge cases where trading vessels would pop into existence or get stuck on terrain have been fixed.
  • The descriptions of A Dream of Red and A Travelling Light now correctly state which stats they enhance.
  • The quantities of items usable in combat are now updated correctly when you gain more of them.
  • Fixed an issue where trading in a vessel occasionally resulted in you getting more money than expected (sorry!).
  • Zee-beast attacks that were reducing terror now increase it, as intended.
  • The audio no longer clips out when selling multiple items in the shop.
  • Removed an edge case that occasionally allowed you to carry legacy stat bonuses over from one set of character lineages to another.
  • If you have multiple copies of an item that is currently equipped to a slot on your ship, they should now appear in your hold as well.
Known issues

  • Though we have increased the spawn rate for some of the zee-beasts needed to complete certain quest chains, we still want to introduce a reliable way to 'summon' them to a given location. We'll look at adding this in an upcoming patch.