Dilution after Miskatonic: Sorta Solved

By AVEC2, in Arkham Horror Second Edition

Hi everyone. Sorry I've been away, work has been nuts. I've been wanting to post about the effects of Miskatonic Horror on dilution, but I haven’t been able to find the time.

Also, a few weeks ago, ricedwlit did a great post on this topic, followed by a great thread. If you haven’t seen it, here’s the link:

http://www.fantasyflightgames.com/edge_foros_discusion.asp?efid=5&efcid=1&efidt=525714&efpag=0

Some of my numbers don’t quite add up with ricedwlit’s, but the difference is never more than a couple percentage points.

Ricedwlit covered whether you could use a few expansions, but he didn’t say whether dilution is a problem if you use all the expansions. In my mind, that’s the real question. Hopefully, the numbers below should give us an idea of what is going on.

In each case, the top row is just the one (or two) expansions that are listed. With each new row you add a new expansion. So, if the first row is Dunwich only, the second row is Dunwich plus Miskatonic, the third row is Dunwich plus Misk plus Dark Pharaoh, etc. The bottom row is what you get if you use all the expansions. I added the expansions mostly chronologically. That’s why Lurker is last. I put Miskatonic in the second row, because I wanted to see how its effects dilute once you add multiple expansions.

This is what the percentages mean:
X% Dunwich: the chance of drawing a card that opens a gate in Dunwich
X% Innsmouth: the chance of drawing a card that opens a gate in Innsmouth, or a card that advances the DOR track (Plans In Motion)
X% Arkham: the chance of drawing a card that opens a gate in Arkham
X% Other: the chance of drawing an “other” card (Strange Sightings, Double Doomers, Next Act Begins, or Intermission)

In my opinion, dilution might not be a problem if you use both the Dunwich board and the Innsmouth board. But if you use only one expansion board, then dilution is definitely an issue.

Also, in the thread above, Tibs and Waddball each suggested rules to deal with dilution.

Tibs’ rule: “draw one, and draw again if it's not Dunwich or Innsmouth”

Waddball’s rule: “if you draw an AH gate or a non-gate, then if the last mythos card was an AH gate, draw and apply a new card”

Just for fun, I analyzed each rule for each of the three cases (Dunwich only, Innsmouth only, Dunwich and Innsmouth). (Disclaimer: As far as I know, both rules were intended to be used only when using board expansion boards.)

Playing with the Dunwich board, but not the Innsmouth board

24.51% Dunwich, 75.49% Arkham, 0.00% Other: just Dunwich
27.59% Dunwich, 67.59% Arkham, 4.83% Other: add Miskatonic
24.54% Dunwich, 69.33% Arkham, 6.13% Other: add Dark Pharaoh
21.05% Dunwich, 68.95% Arkham, 10.00% Other: add KiY
18.87% Dunwich, 70.28% Arkham, 10.85% Other: add Kingsport
17.02% Dunwich, 71.06% Arkham, 11.91% Other: add Black Goat
16.88% Dunwich, 70.46% Arkham, 12.66% Other: add Innsmouth*
15.44% Dunwich, 72.97% Arkham, 11.58% Other: add Lurker

*Even you’re not playing with the Innsmouth board, you might add the mythos cards from Innsmouth Horror don’t directly relate to the Innsmouth board. All two of them: Strange Sightings and Innsmouth Plague. I didn’t include “Plans In Motion” because it advances the DOR track. Not much point in including that card if you don’t use the Innsmouth board.

As you can see, if you play with Dunwich, Miskatonic, and only one or two other expansions, then dilution isn’t too much of a problem, like ricedwlit said. However, if you play with all the expansions, the chance of a gate opening in Dunwich goes down from 24.51% to 15.44%. The chance of a gate opening in Arkham also goes down, but not by much.

Basically, with all the expansions, about 10% of the cards are “other” cards. In order to make room for them, Dunwich takes a 10% hit. So, if you play with just the Dunwich board, Dunwich will be a very sleepy town, even with Miskatonic Horror added.

If Tibs’ rule was implemented, it would result in these probabilities:
28.55% Dunwich, 61.66% Arkham, 9.79% Other

As you can see, with this rule Dunwich would be okay. But Arkham itself would take a 14% hit in order to make room for “other” cards. Instead of Dunwich being sleepy, Arkham would be sleepy.

Waddball’s rule fares a little bit better:
25.19% Dunwich, 64.47% Arkham, 10.34% Other

Arkham still takes an 11% hit, though.

Playing with the Innsmouth board, but not the Dunwich board

33.33% Innsmouth, 64.71% Arkham, 1.96% Other: just Innsmouth
37.93% Innsmouth, 55.86% Arkham, 6.21% Other: add Miskatonic
33.74% Innsmouth, 58.90% Arkham, 7.36% Other: add Dark Pharaoh
31.61% Innsmouth, 61.49% Arkham, 6.90% Other: add Dunwich*
27.95% Innsmouth, 62.19% Arkham, 10.45% Other: add KiY
24.66% Innsmouth, 64.13% Arkham, 11.21% Other: add Kingsport
22.36% Innsmouth, 65.45% Arkham, 12.20% Other: add Black Goat
20.52% Innsmouth, 68.28% Arkham, 11.19% Other: add Lurker

*These are the 11 cards from Dunwich Horror that open gates in Arkham.

We see pretty much the same story as with the Dunwich board. If you play with only one or two expansions, you’ll be okay. If you play with all the expansions, the Innsmouth board takes a big hit in order to make room for the extra “other” cards. Also, Arkham itself becomes slightly more active. I assume this is because of the 11 extra cards from Dunwich Horror.

If we try Tib’s rule here, the probabilities work out to:
32.42% Innsmouth, 58.06% Arkham, 9.52% Other

In this case, Arkham still takes a hit, but it’s only about a 7% hit. That seems pretty good.

With Waddball’s rule, it would be pretty much the same:
31.73% Innsmouth, 58.66% Arkham, 9.61% Other

Playing with both the Dunwich board and the Innsmouth board

18.12% Dun, 24.64% Inns, 55.80% Ark, 1.45% Other: Dunwich and Innsmouth
22.10% Dun, 30.39% Inns, 42.54% Ark, 4.97% Other: add Miskatonic
20.10% Dun, 27.64% Inns, 46.23% Ark, 6.03% Other: add Dark Pharaoh
17.70% Dun, 24.34% Inns, 48.67% Ark, 9.29% Other: add KiY
16.13% Dun, 22.18% Inns, 51.61% Ark, 10.08% Other: add Kingsport
14.76% Dun, 20.30% Inns, 53.87% Ark, 11.07% Other: add Black Goat
13.65% Dun, 18.77% Inns, 57.34% Ark, 10.24% Other: add Lurker

First of all, the “ideal” distribution of probabilities is:
18.44% Dun, 25.08% Inns, 52.74% Ark, 3.74% Other

The ideal distribution is where the undiluted probabilities are shrunk proportionally until they add up to 100%. If you’re playing with just Dunwich Horror, Dunwich cards have a 24.51% chance of being drawn. If you’re playing with just Innsmouth Horror, Innsmouth cards have a 33.33% chance of being drawn. The chance of Arkham cards being drawn is 75.49% (with Dunwich) and 64.71% (with Innsmouth). Those chances average out to 70.10%. There is also a 4.97% chance of drawing “other” cards. I got that last number by calculating the chance of getting “other” cards if you combine DH, IH and MH.

So, the “raw ideal” distribution is:
24.51% Dun, 33.33% Inns, 70.10% Ark, 4.97% other.

In order to get those probabilities to add up to 100%, you need to shrink them down to 75.24% of their original sizes. That results in the “ideal” distribution, above. As you can see, if you play with Dunwich and Innsmouth, but no other expansions (including Miskatonic), the distribution is actually really close to the ideal distribution.

If you add all the expansions, it also isn’t too far from the ideal distribution. Dunwich and Innsmouth are a little sleepy, and Arkham is a little busier than it should be, but it’s not too bad.

By the way, if you use Tibs’ rule, these are the results:
22.91% Dun, 31.50% Inns, 38.68% Ark, 6.91% Other

Those results are dreadful (sorry Tibs!). The values for Dunwich and Innsmouth are inflated, and the chance of drawing an Arkham location is way too low.

Waddball’s rule
18.97% Dun, 26.08% Inns, 46.63% Ark, 8.32% Other

Those results aren’t bad at all. Arkham frequencies take a 6% hit, which is probably tolerable. By the way, Waddball himself reported this distribution: 49% AH, 18% DH, 24% IH, and 9% non-gates. His numbers are close to mine, but I’m not sure why they don’t match exactly. It could be because I consider “Plans In Motion” to be an Innsmouth card, not an “other” card.

So, what’s to be done?

If you play with all the expansions and both boards, you’d probably be okay if you didn’t do anything. Just put everything into one huge mythos deck. Dunwich and Innsmouth would be *slightly* sleepy, but it probably wouldn’t be enough that you’d notice. If you used Waddball’s rule, the probabilities would be even closer, though Arkham would be very slightly quieter than it should be.

I have a couple caveats with these approaches. The first is with Waddball's rule. With his rule, drawing an Arkham location will reduce the probability that the next location will also be in Arkham. The problem is that, if you could make an education guess about what the Mythos deck will do next turn, it may give you an unfair advantage.

My second concern is you will almost never draw “The Story Continues” or “Old Debts Come Due.” If you play with just the Dunwich Horror expansion, each of those cards goes into a 103 card deck. If you play with everything, the deck size is 294 cards, almost three times as big. This means that, if you play with just Dunwich Horror, in 15 turns you have about a 15% chance of drawing Old Debts Come Due. If you play with all the expansions, in 15 turns you would only have a 5% chance of drawing that card. If you play with all the expansions, you should seriously consider removing the Wizard’s Hill encounter where you can make a deal with the Dark Man. He will very rarely collect on his debt.

If you play with just the Innsmouth board, I recommend you use Tibs’ rule or Waddball’s rule. Arkham would be slightly sleepy, but not by much. The Dark Man of Wizard’s hill wouldn’t be an issue, since Wizard’s Hill isn’t in play. However, you would almost never see The Story Continues, which would be an issue with Bast.

If you play with just the Dunwich board, then you have a problem. Playing with all the expansions makes Dunwich way too sleepy. Playing with Tibs’ rule, or with Waddball’s rule, fixes Dunwich, but both rules make Arkham way too sleepy. And the Dark Man of Wizard’s Hill is a problem.

If you play with only the Dunwich board, I recommend you prep the mythos deck as follows:

• 24 Dunwich cards
• 72 Arkham cards
• 5 “other” cards
• The Story Continues and Old Debts Come Due
103 cards total

23.53% are Dunwich cards, which is 96.00% of its undiluted value.
71.57% are Arkham cards, which is 94.81% of its undiluted value.
4.90% are “other” cards, which is 101.49% of its undiluted value.

If you play with only the Innsmouth board, I recommend you throw everything in and use Tibs’ rule or Waddball’s rule. However, if you want the probabilities to be exact, or if you use Bast a lot, you can prep the mythos deck as follows:

• 32 Innsmouth cards (potentially including Plans In Motion)
• 64 Arkham cards
• 6 “other” cards
• The Story Continues
103 cards total

31.37% are Innsmouth cards, which is 94.12% of its undiluted value.
62.75% are Arkham cards, which is 94.12% of its undiluted value.
5.88% are “other” cards, which is 94.72% of its undiluted value.

If you play with both boards, I recommend that you just throw it all in. If you don’t mind playing with Waddball’s rule, it would improve the probabilities. However, if you still feel like things are off kilter, you can prep the deck as follows.

• 19 Dunwich cards
• 26 Innsmouth cards (potentially including Plans In Motion)
• 53 Arkham cards
• 4 “other” cards
• The Story Continues and Old Debts Come Due
103 cards total

18.45% are Dunwich cards, which is 75.26% of its undiluted value.
25.24% are Innsmouth cards, which is 75.73% of its undiluted value.
52.43% are Arkham cards, which is 73.76% of its undiluted value.
3.88% are “other” cards, which is 78.14% of its undiluted value.

Whew! If you made it this far, you deserve, um, something.

Wow, good bunch of numbers there. @@

I've got an untested theory to solve the dilution issue with my grand mixed together set. What I've done is put the Miskatonic Mythos cards that mention Dunwich and Innsmouth seperated and mixed with the original Dunwich and Innsmouth cards - forming 3 separate decks (Arkham, Dunwich, innsmouth). When using those boards, what I do is switch off on the boxes every turn when they're mixed. Now, you think this would lead to an over abundance of stuff happening on the expansion boards, but I believe Miskatonic has a way to solve that with the dual-gate cards. When one of those is drawn, I follow this procedure:

1) If the Expansion gate is Unopened, a Gate Opens.

2) If the Expansion gate is Opened, Check to see if the Arkham Gate is unopened, and open a gate there.

3) If both gates are open, a Monster Surge occurs.

This should balance out the Arkham and Expansion gates, causing the expansion boards to be more dangerous while still allowing a good healthy mix of Arkham happenings.

Of course, this is as-yet untested, but I'm hoping to give it a go over the next few days.

avec said:

If you play with only the Innsmouth board, I recommend you throw everything in and use Tibs’ rule or Waddball’s rule.

Throw everything in except for Dunwich cards, of course.

fantastic, keep it forever info - thanks! So, they *almost* fixed it - great news! What though of the frequency of gate bursts? They seem to have become quite a bit more frequent. I have changed my basic approach to "Ill need at least 7 and now maybe even 8 or 9 seals" This is from playing KH-BG-MH. Now my games are longer and often do not get completed before setdown.

Yikes, sorry about all the typos. I'll clean this report up before posting it to the Reference Materials section.

Master Fwiffo - I'm not sure what you mean by "switch off on the boxes." If you house rule it so that MH's alternate gate cards can potentially open either gate on the card, it may make the problem worse. If you play with all the expansions, Arkham tends to be busier than it should be, while Dunwich and Innsmouth tend to be quieter. Arkham doesn't really need a boost unless you're also using a house rule like Tibs' or Waddball's.

dj2.0 - Good question about the gate bursts. I'll check it out when I get a chance.

avec said:

Some of my numbers don’t quite add up with ricedwlit’s, but the difference is never more than a couple percentage points.

Being within a couple of % points is good news given that my figures where approximations (since # of mythos in small expansion / kingsport are close, but not exact).

avec said:

Whew! If you made it this far, you deserve, um, something.

As do you for crunching all of these numbers!

On side note: sometime this weekend I'll be posting an updated version of my encounter spreadsheet to BGG. In addition to including data for the CotDP (revised) and MH, it also has new sections on the breakdown for the gates appearing in each town as well as what % likelihood is for each type of environment card (for those who use the new Next Act mechanic).

avec said:

Yikes, sorry about all the typos. I'll clean this report up before posting it to the Reference Materials section.

Master Fwiffo - I'm not sure what you mean by "switch off on the boxes." If you house rule it so that MH's alternate gate cards can potentially open either gate on the card, it may make the problem worse. If you play with all the expansions, Arkham tends to be busier than it should be, while Dunwich and Innsmouth tend to be quieter. Arkham doesn't really need a boost unless you're also using a house rule like Tibs' or Waddball's.

I don't think I explained it clearly enough. For example, Turn 1, I draw from Arkham Mythos Pile, turn two, I draw from Dunwich, and turn three, back to Arkham again. Keep in mind the Dunwich pile has all the Miskatonic cards with the Dunwich gates, as well as all the Dunwich expansion mythos cards (including those that have Arkham on it).

This keeps Dunwich from being too quiet, and because it still has the potential to open gates in Arkham, it also doesn't make it too busy.

We played a test game on it earlier today. We got creamed by Glaaki (despite the fact the Terror Level never rose through the whole game - too many monster hunters, not enough gate sealers!), and Dunwich seemed appropriately busy. It was aproximately one gate in Dunwich to every two gates in Arkham, but again, that was just one.

The only problem I could forsee is that you know which turns a gate *won't* open in Dunwich, so it is potentially exploitable in a minor way.

I don't even know which of my rules you're talking about: I've made at least three anti-dilution techniques.

Lately I've said "screw it" and haven't used anything. Miskatonic handles things sufficiently for me. The Act cards are fixed, which is what I cared about the most, and with relatively quieter expansion towns I can get away with using four investigators instead of six. It's nice this way.

ricedwlit: Thanks!

Tibs said:

I don't even know which of my rules you're talking about: I've made at least three anti-dilution techniques.

Lately I've said "screw it" and haven't used anything. Miskatonic handles things sufficiently for me. The Act cards are fixed, which is what I cared about the most, and with relatively quieter expansion towns I can get away with using four investigators instead of six. It's nice this way.

Um, it's the rule that I quoted, from the thread that I cited. Here's the full text:

"By my calculations, using all expansions:

Dunwich gate: 14%
Innsmouth gate: 18%

The original percentages are 25% and 32%, which is very close to double. So playing with a "draw one, and draw again if it's not Dunwich or Innsmouth" rule would work very well. Act cards are no longer a concern."

When I got back to the forums, I saw there was extensive discussion about Miskatonic and dilution. I wanted to contribute without reinventing the wheel. So I read about everyone's ideas for fixing dilution and ran numbers on them. The rule you suggested works pretty well if you don't use the Dunwich board. Actually, it's one of the best fixes I know of in that case. But if you use both boards, the cure is considerably worse than the disease.

Tibs said:

Lately I've said "screw it" and haven't used anything. Miskatonic handles things sufficiently for me. The Act cards are fixed, which is what I cared about the most, and with relatively quieter expansion towns I can get away with using four investigators instead of six. It's nice this way.

I'm in a similar spot; basically, at some point I just sort of decided that I no longer have any sense of what the "correct" distribution of gates should be. Comparing it to that in the base set and a given board expansion does seem like the best way to capture the designers' original intent, but really, as long as it's a challenge and I don't feel like entire boards are going to waste, it's all good.

That said, I am still completely fascinated by mathematical breakdowns of this stuff, so thanks for that, Avec

Oh jeez yeah, there it is. Now I remember saying it, too.

That was also based on my rough calculation about what MH gate frequency could be. Of course, now we know the true percentages are.

Actually, avec, I re-did the numbers with the actual known MH frequencies, and you may like what you see. When using the rule, "if your first Mythos card does not open a gate in Dunwich or Innsmouth, draw again":

Chance of getting a DH gate: 23.0%
(compare that to the chance of getting a DH with just the DH expansion: 24.5% )

Chance of getting a IH gate: 31.0%
(compare that to the chance of getting a IH with just the IH expansion: 32.4% )

Chance of getting an Arkham gate: 38.9% (Its 39.8% if you count Lurker "double" gates twice)

The remaining unaccounted 7.2% represents non-gate Mythos cards.

It looks pretty good. The chances of a gate opening is pretty level between all three towns, and the individual chances of DH and IH gates are extremely close to their originals. No towns will be ghost towns.

Tibs said:

Oh jeez yeah, there it is. Now I remember saying it, too.

That was also based on my rough calculation about what MH gate frequency could be. Of course, now we know the true percentages are.

Actually, avec, I re-did the numbers with the actual known MH frequencies, and you may like what you see. When using the rule, "if your first Mythos card does not open a gate in Dunwich or Innsmouth, draw again":

Chance of getting a DH gate: 23.0%
(compare that to the chance of getting a DH with just the DH expansion: 24.5% )

Chance of getting a IH gate: 31.0%
(compare that to the chance of getting a IH with just the IH expansion: 32.4% )

Chance of getting an Arkham gate: 38.9% (Its 39.8% if you count Lurker "double" gates twice)

The remaining unaccounted 7.2% represents non-gate Mythos cards.

It looks pretty good. The chances of a gate opening is pretty level between all three towns, and the individual chances of DH and IH gates are extremely close to their originals. No towns will be ghost towns.

Heh, I'm starting to think my original post wasn't very well organized. Or maybe it just had too much stuff in it, because there seems to be some miscommunication.

If you go back to my original post, you'll see that I got virtually the same numbers that you did:

"if you use Tibs’ rule, these are the results:
22.91% Dun, 31.50% Inns, 38.68% Ark, 6.91% Other"

I'll tell you why I don't like this distribution. If you play with just Dunwich, 25% of the mythos cards should open gates in Dunwich. The remaining 75% of the cards should open gates in Arkham. If you with play just Innsmouth, 33% of the mythos cards should activate the Innsmouth board, either by opening a gate there, or by advancing the DOR track. 65% of the mythos cards should open gates in Arkham. If we use the rule you described, then the Dunwich number is right, and the Innsmouth number is right, but the Arkham number plummets from 75% (or 65%) down to under 40%. Yeeouch.

That's why I think this distribution is ideal:

18.44% Dun, 25.08% Inns, 52.74% Ark, 3.74% Other

The "undiluted" percentages for each board are: 25% Dunwich, 33% Innsmouth, 70% Arkham, 5% other. Trouble is, that doesn't add up to 100%. If you squeeze each of those numbers proportionally, so that they add up to 100%, you get the ideal distribution.

So, when I compare the ideal distribution with your distribution, it looks to me like your percentages for Dunwich and Innsmouth are too high and the percentage for Arkham is too low.

Master Fwiffo said:

avec said:

Yikes, sorry about all the typos. I'll clean this report up before posting it to the Reference Materials section.

Master Fwiffo - I'm not sure what you mean by "switch off on the boxes." If you house rule it so that MH's alternate gate cards can potentially open either gate on the card, it may make the problem worse. If you play with all the expansions, Arkham tends to be busier than it should be, while Dunwich and Innsmouth tend to be quieter. Arkham doesn't really need a boost unless you're also using a house rule like Tibs' or Waddball's.

I don't think I explained it clearly enough. For example, Turn 1, I draw from Arkham Mythos Pile, turn two, I draw from Dunwich, and turn three, back to Arkham again. Keep in mind the Dunwich pile has all the Miskatonic cards with the Dunwich gates, as well as all the Dunwich expansion mythos cards (including those that have Arkham on it).

This keeps Dunwich from being too quiet, and because it still has the potential to open gates in Arkham, it also doesn't make it too busy.

We played a test game on it earlier today. We got creamed by Glaaki (despite the fact the Terror Level never rose through the whole game - too many monster hunters, not enough gate sealers!), and Dunwich seemed appropriately busy. It was aproximately one gate in Dunwich to every two gates in Arkham, but again, that was just one.

The only problem I could forsee is that you know which turns a gate *won't* open in Dunwich, so it is potentially exploitable in a minor way.

Ok. If I understand correctly, on Turn 1 you have a 100% chance of opening a gate in Arkham. On Turn 2, you draw from the Dunwich deck. That deck has 25 single gate Dunwich cards, 15 mutl-gate (Miskatonic) Dunwich cards, and 11 Arkham cards. That gives you a 40/51, or 78% chance of drawing a Dunwich card. Let's say that a gate opens on Wizard's Hill on Turn 2.

The next time you draw from the Dunwich deck is Turn 4. Because there is a gate open on Wizard's Hill, 8 cards in the Dunwich deck will switch from being Dunwich cards to being Arkham cards. So, on turn 4, you have a 31/50, or a 62% chance of getting a Dunwich card and a 19/50 chance of getting an Arkham card. Let's say that a gate opens on Gardner's Place on Turn 4.

On Turn 6, 4 cards will switch to being Arkham cards. You now have a 26/49, or a 53% chance of getting a Dunwich card, and a 23/49 chance of getting an Arkham card.

For the first 6 turns, your chance of getting Dunwich cards are as follows:

Turn 1: 0% Dunwich, 100% Arkham
Turn 2: 78% Dunwich, 22% Arkham
Turn 3: 0% Dunwich, 100% Arkham
Turn 4: 62% Dunwich, 38% Arkham
Turn 5: 0% Dunwich, 100% Arkham
Turn 6: 53% Dunwich, 47% Arkham

On average, over your first six turns, for any given turn, you have a 32% chance of drawing a Dunwich card. That's pretty high. If you use both boards, and have an Innsmouth deck, percentages look like this:

Turn 1: 0% (draw from the Arkham deck)
Turn 2: 78%
Turn 3: 0% (draw from the Innsmouth deck)
Turn 4: 0% (draw from the Arkham deck)
Turn 5: 62%
Turn 6: 0% (Innsmouth deck)
Turn 7: 0% (Arkham deck)
Turn 8: 53%
Turn 9: 0% (Innsmouth deck)

The average chance of drawing a Dunwich card over nine turns is 22%. That's still pretty high. Also, if you draw a low frequency Dunwich location in your first couple of draws, the average chance of drawing a Dunwich card will be even higher. This is because fewer Miskatonic cards will switch from Dunwich locations to Arkham locations.

I may have said this before, but so what if Arkham's gate frequency is 40%? Innsmouth and Dunwich have mechanics that are directly proportional to the frequency of gates opening. Arkham's mechanic isn't as critical in that regard. It will still be above Innsmouth's and Dunwich's frequencies. Remember that Innsmouth is an entire town , like Arkham, and Dunwich covers the entire countryside. It makes sense that gates are nearly identically frequent between all three regions. Plus, more gates in other towns means more need to travel, which justifies the board handicap.

Just finished an everything-game with my rule, and it worked well. Two gates in Innsmouth, three gates in Dunwich, and like 6 or 7 in Arkham. One rift opened and another nearly opened. Act II was out. Five investigators, and came quite close to sealing even though we blew a ton of clues in bad luck early on. Good game; I think I'll play another!

Obviously, you can play however you want. Arkham has 9 neighborhoods, Innsmouth and Dunwich each have three. If you want to, you can say that Innsmouth is just as big as Arkham. You can reduce Arkham's gate frequency down to 40%, or even lower. You can say that Innsmouth hotspots like Devil Reef are super, super hot compared to hotspots in Arkham. And cool spots in Arkham like the Science Building are super, super cold compared to cool spots in Innsmouth.

You could make it so that the Woods is only about as active as the Marsh Refinery, that the Unnameable is no more active than Y'ha-nthlei, and that activity at the Science Building is so rare as to be almost negligible. It doesn't sound like very much fun to me personally, but if that's your style then go for it.

avec said:

Master Fwiffo said:

avec said:

Yikes, sorry about all the typos. I'll clean this report up before posting it to the Reference Materials section.

Master Fwiffo - I'm not sure what you mean by "switch off on the boxes." If you house rule it so that MH's alternate gate cards can potentially open either gate on the card, it may make the problem worse. If you play with all the expansions, Arkham tends to be busier than it should be, while Dunwich and Innsmouth tend to be quieter. Arkham doesn't really need a boost unless you're also using a house rule like Tibs' or Waddball's.

I don't think I explained it clearly enough. For example, Turn 1, I draw from Arkham Mythos Pile, turn two, I draw from Dunwich, and turn three, back to Arkham again. Keep in mind the Dunwich pile has all the Miskatonic cards with the Dunwich gates, as well as all the Dunwich expansion mythos cards (including those that have Arkham on it).

This keeps Dunwich from being too quiet, and because it still has the potential to open gates in Arkham, it also doesn't make it too busy.

We played a test game on it earlier today. We got creamed by Glaaki (despite the fact the Terror Level never rose through the whole game - too many monster hunters, not enough gate sealers!), and Dunwich seemed appropriately busy. It was aproximately one gate in Dunwich to every two gates in Arkham, but again, that was just one.

The only problem I could forsee is that you know which turns a gate *won't* open in Dunwich, so it is potentially exploitable in a minor way.

Ok. If I understand correctly, on Turn 1 you have a 100% chance of opening a gate in Arkham. On Turn 2, you draw from the Dunwich deck. That deck has 25 single gate Dunwich cards, 15 mutl-gate (Miskatonic) Dunwich cards, and 11 Arkham cards. That gives you a 40/51, or 78% chance of drawing a Dunwich card. Let's say that a gate opens on Wizard's Hill on Turn 2.

The next time you draw from the Dunwich deck is Turn 4. Because there is a gate open on Wizard's Hill, 8 cards in the Dunwich deck will switch from being Dunwich cards to being Arkham cards. So, on turn 4, you have a 31/50, or a 62% chance of getting a Dunwich card and a 19/50 chance of getting an Arkham card. Let's say that a gate opens on Gardner's Place on Turn 4.

On Turn 6, 4 cards will switch to being Arkham cards. You now have a 26/49, or a 53% chance of getting a Dunwich card, and a 23/49 chance of getting an Arkham card.

For the first 6 turns, your chance of getting Dunwich cards are as follows:

Turn 1: 0% Dunwich, 100% Arkham
Turn 2: 78% Dunwich, 22% Arkham
Turn 3: 0% Dunwich, 100% Arkham
Turn 4: 62% Dunwich, 38% Arkham
Turn 5: 0% Dunwich, 100% Arkham
Turn 6: 53% Dunwich, 47% Arkham

On average, over your first six turns, for any given turn, you have a 32% chance of drawing a Dunwich card. That's pretty high. If you use both boards, and have an Innsmouth deck, percentages look like this:

Turn 1: 0% (draw from the Arkham deck)
Turn 2: 78%
Turn 3: 0% (draw from the Innsmouth deck)
Turn 4: 0% (draw from the Arkham deck)
Turn 5: 62%
Turn 6: 0% (Innsmouth deck)
Turn 7: 0% (Arkham deck)
Turn 8: 53%
Turn 9: 0% (Innsmouth deck)

The average chance of drawing a Dunwich card over nine turns is 22%. That's still pretty high. Also, if you draw a low frequency Dunwich location in your first couple of draws, the average chance of drawing a Dunwich card will be even higher. This is because fewer Miskatonic cards will switch from Dunwich locations to Arkham locations.


Actually, those percentages are EXACTLY what I was shooting for. If you go by percentages based on unstable locations, there's 11 in Arkham, 5 in Dunwich and and 4 in Insmouth.

With Dunwich, there's 5/16 Unstable locations in Dunwich, which, all things being equal, should create 31% of the gate draws. With a 32% chance of drawing one of these, that's almost exactly the same percentage. Wow.

Throwing insmouth in, that's 5/20, or 25% compared to 22%. For what I was shooting for, my method seems to nail it exactly. If the Insmouth numbers are even half that good, that's astoundingly close to what I wanted.

Master Fwiffo said:

Actually, those percentages are EXACTLY what I was shooting for. If you go by percentages based on unstable locations, there's 11 in Arkham, 5 in Dunwich and and 4 in Insmouth.

With Dunwich, there's 5/16 Unstable locations in Dunwich, which, all things being equal, should create 31% of the gate draws. With a 32% chance of drawing one of these, that's almost exactly the same percentage. Wow.

Throwing insmouth in, that's 5/20, or 25% compared to 22%. For what I was shooting for, my method seems to nail it exactly. If the Insmouth numbers are even half that good, that's astoundingly close to what I wanted.

Glad to hear that it works for you. Keep in mind that Dunwich has only one hotspot (Wizard's Hill) and three cool spots. If that's not an issue for you, more power to you.

avec said:

Master Fwiffo said:

Actually, those percentages are EXACTLY what I was shooting for. If you go by percentages based on unstable locations, there's 11 in Arkham, 5 in Dunwich and and 4 in Insmouth.

With Dunwich, there's 5/16 Unstable locations in Dunwich, which, all things being equal, should create 31% of the gate draws. With a 32% chance of drawing one of these, that's almost exactly the same percentage. Wow.

Throwing insmouth in, that's 5/20, or 25% compared to 22%. For what I was shooting for, my method seems to nail it exactly. If the Insmouth numbers are even half that good, that's astoundingly close to what I wanted.

Glad to hear that it works for you. Keep in mind that Dunwich has only one hotspot (Wizard's Hill) and three cool spots. If that's not an issue for you, more power to you.


It might be artificially inflating the 'cool' spot percentages, but that's not necessarily a bad thing - after all, if it becomes too predictable, everybody knows to just seal Wizards Hill first, and there's no actual indication in the game which spots are more likely.

Well, not necessarily. Hot spots like Wizard's Hill have more gate bursts, so if you're looking for a permanent seal, it's best to avoid them.

Master Fwiffo said:

It might be artificially inflating the 'cool' spot percentages, but that's not necessarily a bad thing - after all, if it becomes too predictable, everybody knows to just seal Wizards Hill first, and there's no actual indication in the game which spots are more likely.

Technically, all of Dunwich is inflated. I mentioned the cool spots to illustrate that Dunwich is quieter than its number of unstable locations would imply.

dj2.0 asked about the frequency of gate bursts. I ran the number of gate burst cards in the total mythos deck (not counting The Story Continues)

Base Game: 0 of 66 (0%)
Add CotDP: 0 of 85 (0%)
Add DH: 14 of 121 (11.57%)
Add KiY: 14 of 147 (9.46%)
Add KH: 21 of 170 (12.35%)
Add BG: 28 of 203 (13.79%)
Add IH: 33 of 239 (13.81%)
Add LT: 40 of 261 (15.33%)
Add MH: 48 of 294 (16.33%)

Turns out dj2.0 is right. When gate bursts were first introduced in Dunwich Horror, their frequency was 11.57%. That number has been edging up with nearly every expansion, until now it's 16.33%. Think twice before sealing high frequency locations, I guess. It's even more dangerous than it used to be.

avec said:

dj2.0 asked about the frequency of gate bursts. I ran the number of gate burst cards in the total mythos deck (not counting The Story Continues)

thanks for this! yes this is really significant...so much so that i have written elsewhere here about changing the way I play - rather than seal straight away if all the locations open as gates are frequent ones, I will close a couple and save up all the clues I need for a run at all the seals at once. Since I did this things started working out more.

Glad I could help! I was pretty surprised to see that the gate burst percentages have been creeping up. Maybe that's why the revised Dark Pharaoh doesn't have gate bursts.

By the way, a revised version of my original post is up in the Reference Materials. The numbers aren't changed, but it's been slightly rewritten to make it (hopefully) easier to read.

avec said:

By the way, a revised version of my original post is up in the Reference Materials. The numbers aren't changed, but it's been slightly rewritten to make it (hopefully) easier to read.

cool! yes it is easier to read, at least for me, so thanks again!. As for the bursts, I am not surprised as it fits my experience of how play has been going since Kingsport.

As for DP, I am not sure FFG can be credited with such arcane insight. I am more inclined to believe they just goofed and forgot to update that part, but its a good reason if they did see it that way. Although given that the small boxes add only about 1.5%, I think I would have preferred a few gate bursts in it.

I cant believe I just said that. All is lost!