Hello!
First of all, sorry for my English; I'm from Spain and here I am, trying to ask about a little doubt about those 2 expansions.
The question is fast and easy: Mythos cards from Unseen Forces must be mixed with Gates of Arkham ones?
In UF Manual, it gives instructions about Mythos cards, but at the moment this expansion was released, there weren't any other expansions. However, in GoA Manual, the only reference i can find is the part in wich we're instructed to change Mythos cards from the Base game with the new Mythos deck.
So, if we follow what is literally written in instructions, AF Mythos cards shouldn't get mixed with the ones from GoA. But, if you read the instructions given in UF Manual, you should be able to add them to any Mythos deck.
I've searched for an official response, or anything in the FAQs in both English and Spanish... But no. There is no answer about this, as if nobody had asked this before. And i find it unusual, because it can change the game itself; they are part of the game and I think it's important to know if they should be, or not, in a regular game of GoA (of course, if you have the expansion).

So, does anyone know if there is any officil answer to my question, or how does it work? I would appreciate personal opinions too, but if there were any method to get an official answer, i would be grateful to know about it. It's a detail i find important.
Thank you and again, sorry for my English. If you don't understand anything, let me know and i would try to explain a bit better... ^^U

Gates of Arkham started what I would call a "reboot" of the Elder Sign game.

GoA and each subsequent expansion is more akin of a standalone game than an actual expansion.
Each of this expansions only uses its own mythos deck.

I don't know if there's an official answer but I'm certain you aren't intended to mix Unseen Forces mythos with Gates of Arkham mythos.
That mythos decks is specifically crafted to have a lot of interactions with expansion's mechanisms, like gates.
Mixing Unseen Forces in would dilute those effects.

But I would advise you to check it yourself. Play a few Gates of Arkham games without Unseen Forces mythos, then play a few games with them.
Then you'll be able to tell which experience you prefer. You might eventually decide that some of the Unseen Forces mythos cards are fitting leaving out the others.

I'm sure you're right; thank you, very much.
I've played until now mixing both Mythos decks (and it was hard and funny -harder with the red Mythos cards xD -) but re-reading the rules a doubt about that came to me and, after a midly-long search in these forums, i decided to ask, directly, creating this thread.
Since i have some free time these days, for sure i'll follow your advice (i'll give a try to both kind of games); but considering that there isn't any FAQs related to this and that you have explained everything really well reasoned, i don't have any reasons to doubt about what you explained. So i, probably, will play one or two more with both Mythos decks mixed by focusing my attention on the result (to notice what you say) and then i'll remove the cards from UF. So, I'll see better that difference that you've commented.
Thank you, very much, for everything! ^^

Hi,

Tsuma is right (as he often is); Gates come with its own Mythos deck and it's the only Mythos deck to be used when playing the Streets of Arkham mode. If you're looking for evidence in the rules, please refer to the 2nd panel of the English rules, Streets of Arkham Setup section, 2nd bullet point (emphasis mine):

"New Mythos Cards: Replace the Mythos deck with the new Mythos deck, made up of only the Mythos cards provided in this expansion."

"replace" is key here: it means you no longer use the previous deck.

Happy gaming!

1st of all, thank you for the response ^^
And about your last point, yes; same in spanish. My doubt was caused because, when i read about mythos cards (and the other points), i assumed they were referring to the basic game. Iassumed all the rules are written counting you only have the basic game, unless they state another thing (for example, there is one point -in the last paragraph of page 4- where they explain what to do do with blessings rewards or curse penalties, if you have UF. But they don't explain anything about black and white dice (obviously, because it is explained in its own rulebook). Then, they have the basis that UF is explained using its rulebook, but they specify the variations of that add-on game. So, if they don't specify, i understood they only referred to the basic product.
With this basis, when i read your paragraph, i assumed i had to change the basic Mythos deck with the new AND THEN, add the UF mythos deck, same as i added b&w dices, investigators, monsters, ancient ones, blessing/cure cards, items/spells........
I don't know if i've explained well, sorry ^^U
In any case, last weekend i played one and a half games (xD i had to dinner and go really early to bed... that's what jobs have... they enslave us xDDDD). And i could see the difficulty change. No... i could LIVE it. xD Almost time mythos cards were opening portals and/or adding tokens to the doom track. It really increased the difficulty. I said before i was sure he was right... and after give a try to this, i've got clear the ideas... Even if it could be played with the UF Mythos cards, it would only lose difficulty.
But, by my part, it's clear how does mythos cards deck works: Only GoA Mythos deck.
Thank you, very much to both for the responses and sorry if it's difficult to understand what i write ^^U (i've got all the words underlined in red xDDD). But thanks for all. Same to you, Julia, happy gaming!

10 hours ago, HaidesTunicaRoja said:

With this basis, when i read your paragraph, i assumed i had to change the basic Mythos deck with the new AND THEN, add the UF mythos deck, same as i added b&w dices, investigators, monsters, ancient ones, blessing/cure cards, items/spells........

Almost correct. You don't add the UF Mythos deck. The UF Mythos deck is used ONLY with the Museum setting provided in the core game.

All other components (investigators, blessings, curses, items, spells, monsters, ancient ones, investigators) are mixed in

After 3 more games, i feel this expansion harder, but still fairly beatable with the correct control... and if you fail, you can still beat it with some more effort. I like it : ) And it's very different the experience using only its mythos deck. Perfect.
If you don't mind, i would like to ask you about an Ancient One: Yog-Sothoth: When i bought UF, it was specified, in the manual, the Ancient Ones that should be replaced with the new cards. But i was reviewng the carss, after the last game and i saw that i have 2 Yog-thoth!! One from the basic game and another one from GoA. The GoA one has the restriction icon, but it only means that this card must be used only in GoA game mode; if it's played another game mode the card should be removed from play.
Then, it gives 2 options:
1- The strict one: Reading rules, nothing specifies to remove the older one, so, you must have both in the Ancients deck.
2- The "human" one: One thinks that, if we use logic, the old one should be removed from game in GoA game mode, but it should be used in the other game modes, removing the new one.
So... I think it's not really important at all, but if they have done again Yog-Sothoth it must be because they think this new one is more "flavoured" and then, it must be better for this game mode, so i think i should remove the old one to increase de difficulty, shouldn't I?
Cheers

If you look at what's stated under the name "Yog-Sothoth", you'll see there's a different title: one's called "The Lurker at the Threshold", and the other one - IIRC - "The Key and the Gate": it's two different versions of the same Ancient One. Thus, the Yog-Sothoth coming with Unseen Forces is supposed to replace the one from the core set, and the Yog-Sothoth coming with Gates is a different version of the same Ancient One

(for the record, we even have a third version, released at Arkham Nights)

I got it; thank you, very much : )