Ruinses, it turns out, are a pile of cards like Curses, with three ways to get them, besides just buying them or something. They only show up in games with a Looter, which is a word you may have been wondering about on Cultist.
Prediction:
(1) More than one type of Shelter (like more than one type of Ruin)
(2) You play with shelters instead of Estates whenever a Looter is present (Start conditions)
(3) "Three ways to gain Ruins" -> I'll bet it's not "Three cards that give Ruins", but rather "Three ways"
Way #1: Other player gives them to you like a curse
Way #2: You give them to yourself as a penalty for a card that would otherwise be too good (We've seen lots of fan cards like this before that have been poo-poo'd. Just like $1 cards and card that take from the trash were poo-poo'd)
Way #3: Something else? Maybe you start with Ruins? Or cards get transformed into Ruins?
I could be very wrong, but it seems to me only three cards that let you get Ruins ever is pretty limiting. There are 35 cards with DA's which means even a 100% DA's game would only have Ruins in it (and if my theory is right Shelters) in about a third of games (35% if I did my math right?) (vs. all of 100% prosperity games having Platinum/Colony). And it would mean overall if you played randomly you would barely ever play with Ruins -> 3 cards in ~200?
It would seem like a bit of a waste to have 50 Ruins and 50 Shelters (?) out of a 400 card set that only get played once in a blue moon...
Ed