I'm thinking Scylla's Well is going to create some confusion. It tells us "Attach to a Location you control. Attached Location becomes a character with..." This is different language than Guardian Pillar.

For example, does the attached Location remain a Location and gains the additional characteristic of Character, or does it lose the original Location qualities and transform into a character? This might be addressed in the FAQ and I missed it, so apologies if this is a moot point.

I think that is the intent, that it is both a Location and a Character.

I'd have to look at the FAQ but my impression is that it becomes both... if it didn't the changing of one from the other I think would discard the attachment...

Penfold said:

No, that wouldn't be a problem. The FAQ tells us:

An attachment only checks the requirements for attaching it when the card enters play. For example, if an attachment had the requirement “Attach to a Servitor character,” and if the Servitor character it was attached to later on loses the Servitor subtype, the attachment would still remain.

I'm also thinking that MAYBE we can learn something from Guardian Pillar (even though the language is different)? It makes me think it will become a Character and not be a Location. The FAQ says:

Also, it is important to note that Guardian Pillar is no longer a support card while it is a character, and that it does retain its name and uniqueness.

Not sure on that one... You can argue from that FAQ entry that Character/Support/Event are mutually exclusive types of cards, but the Well isn't using those types. Location is merely an a subtype, so it shouldn't be affected.

The rulebook states on p4 "There are five different types of cards in the Call of Cthulhu LCG". I didn't notice anyplace that said that a card must belong to only one of these types, but the Guardian Pillar ruling sort of implies that maybe this is the case. Even so, Well sidesteps it because even if Character/Support are mutually exclusive Character/Location don't seem to be.

Got a rapid response from Damon:

[after attaching Scylla's Well] The location is both a character and a support card with the location subtype.

The discard I was referring to is this one,

from the FAQ
1.3 When a card changes type (character,
support, event, or story), any cards
that are attached to it are immediately
discarded from play.

The implication is that I attach Syclla's Well and the support becomes a character and then the attachment falls off because the card changed types.

I think the solution to 1.3 is that the change happens during the attachment, so by the time the attachment is complete the card is already a Character.

At Kellen's insistence, I asked Damon about the precedent from Guardian Pillar in the FAQ. He reversed his decision, in the following reply (emphasis mine):

Thanks for that... I'll have to take a look at what implications there are for the existing card pool, but until a new FAQ comes out you should treat Syclla's Well as a Character card and as a Location, but not as a Support card . Confusing I know, but until a FAQ can clearly outline what happens with cards gaining or changing card types specifically rather than in passing, SW needs to conform to the precedent set by Guardian Pillar.

Sounds good, and I agree that consistency is important.