Infinite Depth in Yoth - Taboo

This deck is built to demonstrate that it’s possible for a solo investigator to descend into Yoth indefinitely. That is: With this deck it’s possible to enter a state such that you are guaranteed to be able to continue increasing your depth in Depths of Yoth indefinitely, with zero risk of failure. (Spoilers for Depths of Yoth, I guess.)

The core means of doing this is the fairly well known combo of All In, Quick Thinking, Double or Nothing, and possibly "Watch this!". If you haven’t seen the combo before, we’ll talk about it in depth later, but the short version is to have those three (or four) cards in your discard, and nothing in your deck. (For Sefina, we will also have a weakness in our discard.) When you take a test, you commit those cards, gaining two actions, possibly some money, and draw those cards from your discard pile, discarding the cards you committed, returning you to the same state you were in before, except with more money and more actions. If you spend fewer actions initiating the test than you gained from it, then you can go forever, assuming you also have a way to know for certain you don’t fail the test, and also assuming you have a way to soak the horror you get from reshuffling your deck. Our deck will use Olive McBride for both of these purposes.

We’ll start by looking at how the deck works in the end state of the scenario, when it's perfectly set up and able to go on doing the same thing forever. Once we understand that, we’ll look at what’s required to reach that state. Before the scenario starts however, we have to draw random basic weaknesses. With 49 xp in the deck (five extra for Streetwise under the May 2019 taboo list), we need to take 5 of them. Many basic weaknesses will stop the deck from going off, while others will work but need some alteration. For the purposes of this discussion, let’s assume our basic weaknesses are all enemies, as the scenario gives us a convenient permanent way to remove them from the picture. Other basic weaknesses that won't stop the deck from working include: The Tower, The 13th Vision, and Haunted.

The Endgame

We're home free once we’ve been able to pilot our deck so that at the beginning of the Mythos Phase the following are true:

We’re on Agenda 7a (VENGEANCE) with at least 125 doom on the agenda. All victory point enemies are in the victory display (Eater of the Depths, Serpent from Yoth, and Yig), and no vengeance enemies are in the display. The remaining eight enemies (3 Pit Warden, 3 Brood of Yig, and 2 Fang of Yig) are either in pursuit if we just increased the current depth, or are in play at our location but exhausted. Our basic weakness enemies are in the pursuit area and will never leave there: once you reach Agenda 7, only serpent enemies will ever leave pursuit.

Assume also that we have all assets in our deck in play except for our Lupara, one Elder Sign Amulet, one Bulletproof Vest, and one Olive McBride. Our The Chthonian Stone and Protective Incantations are sealing both s and the , with the The Chthonian Stone holding a . Our assets have no horror or damage, except that Joey "The Rat" Vigil may have a horror. Sefina has enough horror that she can use Run For Your Life, but fewer than three damage.

Assume all three of our The Painted Worlds were removed from the game before we ran out of cards under Sefina. This leaves 20 cards combined in our deck that aren't in play or removed from the game: 4 assets, 5 events, 10 skills, and 1 treachery. We have in our hand a Double or Nothing, a Quick Thinking, and an All In. Our deck has exactly 5 cards in it. The ten remaining cards in our hand and deck include another Double or Nothing, Quick Thinking, All In, and Olive McBride.

We have a lot of resources. More specifically—when we get back to the investigation phase, we’ll have the opportunity to use our loop to gain as many resources as needed. Assume we now have enough to pay for what will happen in the Mythos Phase in the worst case scenario, after which we’ll be able to go infinite and get our money back up to the level needed for the next cycle. I haven’t worked out how much that is exactly (it will increase over time, as the depth and the amount of doom in play increase) but there are only finitely many fairly predictable steps involved in getting back to a position where we have the ability to print money on demand, so the problem of working out how much is needed is solvable. Assume we solved it and have at least that much money.

Assuming all the above are true at the start of the round, we begin the Mythos Phase:

We add a doom to the agenda, and begin drawing encounter cards. VENGEANCE says we draw an extra encounter card for each doom in play, so this’ll take a while. We'll address what happens with the simple encounter cards later...the complicated part is how we take tests. When we draw an encounter card with a test we do the following:

--In the player window before committing cards: If this isn't the first or second test of the phase, we use Joey "The Rat" Vigil to play a Bulletproof Vest and an Elder Sign Amulet.

--We commit All In, Double or Nothing, and Quick Thinking to the test, and pump the appropriate skill so that we’re 14 above the test value. (With Arcane Studies and Hard Knocks in play we can pump anything, although Streetwise might be cheaper.)

--When revealing a token, we activate Olive McBride. If is one of the three tokens chosen, we use the other two. If it isn’t, choose any two tokens other than . (We must avoid as it could draw into .) The result will be two tokens whose numerical modifier is at worst a combined -8. We succeed the test by 5.

--When activating All In twice, we’ve ensured that at some point we will draw Stars of Hyades with an empty deck. When this happens, since we can’t shuffle a card into an empty deck, Stars of Hyades stays in hand and we resolve its revelation effect. It deals one damage and one horror which we usually place on Olive, killing her. For most tests, we began the test with an empty deck and 6-9 cards in our discard pile, so we looped our deck once before Hyades hit us. If so, put that horror on Olive, and then kill Olive with the horror and damage from Stars. For the first test of the phase however, we looped our deck AFTER getting hit by Hyades. In that case, put the horror on the Alyssa Graham. For the second test of the phase, we might be getting hit by Hyades on BOTH All In's. If this is the case, put the damage and horror on Joey and Alyssa from the first All In, and then put the deck shuffling horror and second Stars' damage on Olive, killing her like usual.

After the test resolves, we have two actions with quick thinking. With our first action we replay Olive McBride. We may have as many as one enemy engaged with us. (If enemies were in pursuit and if the card we drew was Serpent's Ire.) If we do have an enemy, we take an attack of opportunity, putting one damage and one horror on our Bulletproof Vest and Elder Sign Amulet. (The relevant enemies all have a one horror one damage attack.)

With the second quick thinking action we do one of the following:

----If there’s an enemy engaged with us, evade it. This triggers a test--go back to the top of these ‘take a test’ instructions.

---Otherwise, if that was the first test of the phase, we drew our 5 card deck on the first All In, discarding Stars of Hyades and Olive McBride, putting our discard pile up to 9 cards. We then shuffled and drew 4-5 cards from the second All In. By the time we're taking our Quick Thinking actions after the test, we'll have 4-5 cards in our deck and 3 cards in our discard pile. (All In, Quick Thinking, Double or Nothing.) If we now take an investigate test following the same instructions, our All Ins will draw the rest of our deck (possibly hitting us with Stars twice if our deck had exactly 5 cards in it, as addressed above). We can go back to the top of these ‘take a test’ instructions.

---Otherwise, if that was our second test of the phase, we’ve avoided replaying our Amulet and Vest in order to be certain that we drew our entire deck. Take one more investigate test to give us a chance to replay our Vest and Amulet.

---Otherwise...we’re all set. Gain a resource with the action I guess.

After any encounter card with a test finishes resolving, if it was the first encounter card with a test on it, we’ll end up taking three tests, drawing our deck, at which point we have all cards in play or in hand, except for Stars of Hyades, All In, Olive McBride, and Quick Thinking which are in our discard pile. By the time we're drawing another encounter card with a test, we’ll have another two cards in discard (Bulletproof Vest and Elder Sign Amulet) either because we replaced them, or because they were destroyed from damage and/or horror, and then we replaced them. This means we’ll have 6 cards in our discard pile and no cards in our deck when the next All In doubling happens. As promised, for any test beyond the first encounter card with a test, we have that the first All In draws 4-5 cards, but the second draws everything causing our Stars of Hyades to hit us AFTER we take our deck shuffling horror, meaning that unless it was our first skill test encounter card of the phase, Olive can always soak Hyades and deck shuffling horror.

Let's discuss how we react to other encounter cards: Serpent's Call: We draw the two encounter cards. (We’re good at those!) Snakescourge: Goes into play. Our items are all blank once we’re going through the entire encounter deck every round. Our Lupara isn't helpful anymore, but our Vests and Amulets don’t need text to soak for us. Ill Omen: We add doom and put the horror on Olive if she has no horror. If we haven’t taken a test yet this phase, we also put it on Olive even if she has exactly one horror. (She won't need to take the deck-looping horror if on the first test of the phase.) Otherwise, put the horror on Elder Sign Amulet.
Ancestral Fear: We do the doom. Deep Dark: Goes into play. We’ll be getting only one clue per location per round once we're going infinite. Low on Supplies: We pay the 2 resources. Lost in the Wilds: We pass the test and it’s discarded. Bathophobia: We pass the test. Children of Valusia: Goes into play. Lightless Shadow: We pass the test. Creeping Poison: We aren’t poisoned. Curse of Yig: Goes on us. We need to make sure we don’t take 3 damage getting set up, as we’ll spend the rest of the game with both of these in our threat area. Serpent's Ire: The first eight times we draw this after increasing depth, we'll draw the eight serpent enemies that are in pursuit. Over the course of three to five passes through the encounter deck (we have lots of doom in play) they’ll enter our location one at a time. Luckily, Serpent’s Ire gives us a test to take immediately after handing us a new enemy, so we’ll be able (with our second Quick Thinking action) to evade it immediately after taking at most one attack of opportunity from playing Olive. Put the resulting damage and horror on the Vest and Amulet.

Damage and Horror Management: We should verify that our plans to put all that horror and damage on our vest and amulet never leave them destroyed them when we still need more soak. We’ve already covered how most damage and horror from Stars of Hyades and from drawing our deck are soaked by Olive. The exceptions to this were in the first two tests of the game, which might have given an extra 2 horror and 1 damage. Because these are one-time hits, we can safely put them on Alyssa and Joey who have room for them. We'll get a chance to heal them in the investigator phase. We’ll also be taking horror from each Ill Omen we draw, and we’ll take a damage and a horror from attacks of opportunity from the first 8 times we draw Serpent's Ire.

A little verification shows that any time we draw an encounter card with a test, we will end up with a shiny new Vest and Amulet before we draw our next encounter card. (If we took attacks of opportunity, we took another test to evade the serpent that attacked, and we got new soaks during that second test, unless that was our first test of the phase, in which case we’re specifically taking three tests in a row to renew our soak before we go back to drawing encounter cards.) Before we took our first test of the phase, we might have taken as much as 4 horror, from drawing both copies of Serpent’s Ire in the deck at the end of one shuffle and then drawing them again at the top of the next shuffle. Two of those horror would’ve gone on Olive. One more horror from an attack of opportunity if this first test was Serpent’s Ire is still not enough to kill our Amulet. The situation between any other two tests will be the same, but Olive can only soak one Ill Omen horror, meaning our Amulet might take just enough horror to be destroyed. In either case we'll have a new Amulet before we draw our next encounter card, and we had enough soak to reach that point without Sefina taking any horror or damage to herself.

We’ve now shown that the deck can survive the Mythos Phase. When we get to the investigator phase we do the following:

--All serpent enemies are exhausted at our location, either from the start of the round or from drawing lots of Serpent’s Ire in the mythos phase. Engage one Pit Warden.We’ve spent an action. --Without spending an action, play a Swift Reflexes to make sure we have more than 5 cards in our discard. (We already had an All In, Double or Nothing, Swift Reflexes, Olive McBride, and Stars of Hyades.) We have 3 actions again. (With only five cards in discard, Stars of Hyades would hit us twice on a doubled All In.)

--We do the following loop to generate resources: Evade the pit warden, committing All In, Quick Thinking, Double or Nothing, "Watch this!", and Run For Your Life. Boost our agility three times with Streetwise. Our skill value is now at 4 (base) + 9 (streetwise) + 9 (committed) = 22. Spend 3 resources when committing "Watch this!". The test’s difficulty is (1 (base) + 3 (Children of Valusia )) x 2 (Double or Nothing)=8. Activate Olive, resolving two non-auto-fail tokens or else two non-tablet tokens. The worst our modifier can be is a -5 and a -3, putting our modified skill value at 14. We succeed by at least 5. We gain two actions, 12 resources, and draw our deck, first taking a horror from looping it (put it on Olive) then taking a damage and a horror from Stars of Hyades which kills Olive. --Use our two actions to first play a fresh Olive (no attacks of opportunity this time), then to engage a Pit Warden again. --Play a Swift Reflexes for an additional action which we use to evade the Pit warden returning to the top of the loop. We have exactly 8 cards in our discard now: the 5 we committed, an Olive, a Stars of Hyades, and a Swift Reflexes. Next time through the loop, we’ll draw 4 or 5 cards off our first All In, and the rest of our deck with the second.

Every time through this loop, we’re spending 11 resources: 3 on Watch This, 2 on Swift Reflexes, and 6 on Streetwise. But we gained 12 resources from Watch This. So every time through this loop nets us a resource. Repeat until we have a lot of resources. How many? Enough to make it back to the next investigate phase.

(Note that this can loop can be made more complicated but more efficient by using both Swift Reflexes and playing a Hot Streak. This fact may be be relevant if you're trying to figure out exactly which basic weaknesses the deck can still work with--something I haven't thought that hard about yet.)

Once we have a lot of resources, we can do a variation of that loop where we play Swift Reflexes twice instead of once to accumulate useful actions. The above loop left our space in the discard pile very tight, but once we’ve got lots of money again, we can omit Run For Your Life and "Watch this!", spending extra money on Streetwise to make up for it. Because of the restriction that Swift Reflexes can’t be used during an action, the timing on this is a little finicky. We use our Quick Thinking actions to play Olive and engage the enemy, then play a Swift Reflex to do something useful, then use our second Swift Reflex to evade again. This version of the loop leaves 7 cards in our discard, meaning we can continue the loop indefinitely as long as that useful action doesn’t put more than two cards in our discard pile.

We now have unlimited actions, with slight restrictions, but with the ability to pass any test using the usual Olive trick.

At this point, the problem branches in a few big ways. For the moment, assume that we can explore the map, we find enough 1-clue locations that we can find depths of Yoth and get the three clues needed to increase the depth. Since we can only get one clue per round because of Deep Dark, this isn't guaranteed--we'll address how to handle the other case in a moment.

If we're in this best possible case, we explore, get the necessary clues, and go to Steps of Yoth, ready to advance at the end of the round. Before that though, we heal our Joey and Alyssa if necessary by running the loop as usual but putting the reshuffle horror on Joey/Alyssa until it kills them, then playing them again fresh once we redraw them again.

Once our board is in good shape and we are ready to go to the next round, we execute the evade loop in such a way that there are exactly 7 cards in our discard pile. We spend our free action drawing a card (put the deck-looping horror on Joey this time) and hope it’s not a Stars of Hyades. If it was a Stars, we put the damage and horror on Joey, killing him, go back into the loop to refresh him and to top up our resources, and then we try again. Eventually we’ll try succeed and get a non-Stars card in hand, so that our deck has exactly 6 cards in it. Instead of evading to go back into the loop, we end our investigation phase, using Alyssa Graham to make sure the top card of our deck isn’t Stars of Hyades. (We can savely give her the horror to move Stars to the bottom if need be.) In the enemy phase nothing happens as all enemies are exhausted. In upkeep we draw a non-Stars card, and then discard down to 8, shedding only cards that aren’t All In, Quick Thinking, Double or Nothing, or Olive McBride. At the end of the round, we increase our depth. As the round ends, we’ve now met the requirements we had at the top of the Mythos Phase, and we're ready to start all over again but with one extra depth.

Now what happens if we can't advance in one round? We won't be able to go through the mythos phase with 8 ready enemies engaged with us, as playing Olive will kill us with attacks of opportunity, or will at least wreck our allies. Instead, we use our infinite action loop to engage and evade the enemies with Slip Away one at a time, succeeding by two. This ensures no enemies are ready during the next mythos phase. We get an additional clue from every location we can reach, and go back to the room full of monsters to set up for the next round.

So that's the end of the loop. We'll be able to descend as long as we can get to the starting position described at the top of this. But how can we get there?

BEGINNING THE LOOP

In the above, we had the weird requirement that there be 125 doom on the Agenda. The reason for this is we wanted to make sure a Pit Viper was in play in the investigation phase, and that requires drawing Serpent’s Ire at least 7 times, and that might require drawing through the encounter deck almost 5 times to ensure. If we can pilot the deck into the infinite loop at least once with a Pit Viper in play, we can run the loop without increasing depth until we get the necessary amount of doom in play, or alternately we can bank enough resources to know that they’ll last us until 125 doom, at which point we’ll be able to refill our resources again.

To reach the point that we can kick the loop off once, the strategy isn’t too complicated: we need to draw cards and putting all those assets into play. Drawing your whole deck and surviving may seem daunting, but remember we also have this neat combo of All In-Quick Thinking-Double or Nothing which is actually pretty helpful at drawing lots of cards as it turns out, so it isn’t nearly as rough as it seems. I’ve been able to do kick off in 10 rounds.