Fallen London – Analysis of the Stacks (EPA of Every Card)

This is an analysis of the EPA of every card in The Stacks, sorted from lowest to highest.

How to Understand the EPA of Every Card in the Stacks

Assumptions

• We always search for the FATE locked book, with a profit of 116 Echoes, and don’t ratket any of the items. As such, this guide should work if a free 116 Echo book comes out.
• We ignore A Chained Volume, the key required for A Chained Volume, the chance of failing the Shadowy check in Phase 3, and the chance of getting caught by the librarians in Phase 3. Because A Chained Volume is so profitable, the actual EPA should still be higher than shown here
• Taking only 5 progress actions in the stacks completes a loop in 22 actions (1+8+1+8+2+2). The EPA of this loop is about 5.2, and as such, 5 progress = 5.2 Echoes. This is our baseline action.
• Keys can be gained and used at a rate of 2 Actions for 15 progress. As such, gaining or using a key is worth 7.5 progress or 7.8 Echoes
• Routes can be fairly reliably used at A Stone Gallery at the rate of 2 Routes and an action for 10 progress. As such, I consider gaining Routes to be 2.5 Progress per Route, and spending 2 Routes for 10 Progress to be a baseline action.
• If you can’t use Routes at A Stone Gallery (because your book doesn’t give you that option), reliable options for using Routes go down to 3 Routes for 5 Progress using the Cartographer’s cards (FATE). If you can’t use either, you should only use Routes at A Tea Room.

• An Atrium (Phase 1) is played often enough to get rid of any incidental Fragmentary Ontologies, so they are worth nothing.
• This guide assumes Noises will never get to 8, as that just seems too unlikely.
• Checks are done with my stats of 336 Watchful, 331 Shadowy, and 15 KT.

• With all that out of the way, I have categorized the Library cards into three categories:
• Misses, that are significantly below baseline value
• Rerolls, which are about baseline value,
• Hits, which are significantly above baseline value

A successful Library strategy involves playing as many Hits and Rerolls as you can, avoiding Misses at all costs.

The Cartographer’s cards will be marked with FATE, and there are no Cartographer options on non-FATE cards that are worth playing over the non-FATE options.

• [L] means that the card is FATE locked
• [W] means that this card likely won’t be in your deck
• [R] means that this card is rarer than other cards

Misses

1. The Shape of the Labyrinth (Phase 2, 6+ Routes)
   • 1 action and 4 Routes for 10 Progress = 10-10 Progress = 0 EPA
   • If you pick up a Fragmentary Ontology from A Librarian’s Office, it can be used to make this card a baseline action, but you usually won’t have one of those.
   • Also clears your hand, improving your card quality
2.  An Atrium (Phase 2)
   • 1 action and 1 Route for 5 Progress = 5-2.5 progress = 2.5 Progress = 2.6 EPA
   • This is technically more profitable if you have 0 Routes, but you should keep a stockpile for A Tea Room
3.  A Discarded Ladder
   • 1 action for 1.5 Routes = 3.75 Progress / 3.9 EPA
   • However, if we assume that using this action leads to Route flooding, requiring spends of 3 Routes / 5 progress, this action has an EPA of 2.6
4.  [L] FATE
   • Best option is 3 Routes for 5 FOs
   • This leads to a loop of this and God’s Eye View, or 3 Routes and 2 actions for 15 Progress = 15-7.5 Progress = 3.9 EPA
5. [W] A God’s Eye View (2 FO per action)
   • 3.5 Actions for 15 progress = 4.28 P/A = 4.45 EPA
   • Get FOs through An Index -> Try to understand the organisation of the library
   • This is just to show that grinding FOs isn’t profitable, if you aren’t grinding FOs you’ll never see this card.
6. A Grand Staircase
   • 1 action and 1 Route for 5 Progress = 5-2.5 progress = 2.5 Progress = 2.6 EPA
   • This is better than it seems, because clearing your hand leads to getting some of the really good cards in the deck. Play this above the other misses, but below anything else.

Rerolls

1. [L] FATE 
   • 1 action for 2 Routes = 5 progress = baseline action
   • However, if we assume that using this action leads to Route flooding, requiring spends of 3 Routes / 5 progress, this action has an EPA of 3.46
   • Try not to use this action, as there are better ways of gaining Routes and too many Route actions run the risk of flooding on Routes
2. An Index – Search for a reference card (Phase 1)
   • 1 action for 2 Routes = 5 progress = baseline action
   • However, if we assume that using this action leads to Route flooding, requiring spends of 3 Routes / 5 progress, this action has an EPA of 3.46
   • Try not to use this action, as there are better ways of gaining Routes and too many Route actions run the risk of flooding on Routes
3. A Stone Gallery
   • You generally want to keep at least 4 Routes for A Tea Room. If you can use 2 Routes and still have 4+, Follow a borehole through the back of a bookcase as a baseline action. This takes priority over most other cards by keeping you low enough to avoid The Shape of the Labyrinth.
   • Otherwise, if you don’t care about having Nightmares 5+, Make your way through the silent gallery can’t bring your Nightmares above 7 and otherwise acts as a baseline action.
   • If you do care about Nightmares 5+, A stone gallery gives .75 Nightmares CP if you have 2 Nightmares items. Getting rid of Nightmares is an exercise left to the reader.
4. A Poison-Gallery – Prepare an antidote
   • The best way to get Salts is from the Bazaar at .2 Echoes
   • Baseline action = 5.2 – .2 Echoes = 5.0 EPA
5.  The Grey Cardinal – Offer the cardinal a furry lunch
   • Baseline action = 5.2 – .01 Echoes = 5.19 EPA
6.  [W] A Terrible Shushing (Noises 4+) – Hurry along
   • Always gives 5 progress, but increases Noises
   • I’ve never seen this card in my 50+ runs
7.  [R] A Glimpse through a Window, A Flowering Gallery
   • Both have 5 progress baseline actions
8. A Black Gallery
   • Baseline action
   • The first time you play this, use a Woesel to fail at Light a Lantern to unlock the A Gaoler-Librarian card
   • After that, Navigate by alternate senses
9. A Dead End?
   • Baseline action, clears your hand
   • I would wait to play this until you only have cards from An Index or worse in your hand, because the miss cards are so bad.

Hits

1.  An Atrium (Phase 1)
   • I have a 67% chance of success with no FOs, and that’s the number I’ll use here
   • 67% of 5 progress + 1.5 Routes = 8.75 progress for 1 action, 33% of nothing
   • Average of 5.83 progress = 6.06 EPA
   • Failure at this card also opens the A Gaoler-Librarian card if A Black Gallery isn’t available
2. [R] A Librarian’s Office (Phase 2, 10 or less progress remaining or no keys) – Pick through the drawers
   • 10% of 2.5 Echoes (Failure), 30% of 4 Echoes (FO), 30% of 4 Echoes and 2.5 Progress (Route), 30% of 4 Echoes and 7.5 Progress (Key)
   • Gives an average of 6.97 EPA, worse than using a key but still well above baseline
3. A Gaoler-Librarian – Try to lift one of its keys
   • I have an 83% chance to pass this check
   • 83% of 7.5 progress for 1 action, 17% of nothing
   • Average of 6.225 progress = 6.474 EPA
   • Required to cash out the key users
4. [R] A Librarian’s Office (Phase 2, at least 15 progress remaining), A Locked Gate
   • These both use keys, which I treat as 7.5 progress = 7.8 EPA
5. [R] A Tea Room?
   • 1 Route and 1 action for 10 progress = 10-2.5 progress = 7.8 EPA
   • This assumes you have at least 5 Routes to 100% the check
6. A Map Room
   • I have a 91% chance to pass this check
   • 91% of 5 Echoes and 3.775 progress (1.5 Routes) for 1 action, 9% of nothing
   • Average of 8.122 EPA
   • [L] FATE: The Cartographer’s option to get progress and noises is slightly better than intentionally failing another action, and might be worth it if you don’t have access to A Black Gallery and can’t draw An Atrium enough to fail it

Conclusion

The Stacks are very random, but this guide should help you figure out why certain cards are good and exactly how good or bad your runs are.