In a board without other cards that trash, can Rats be good?
I thought about this examples:
1. Scrying Pool. In this case, each Rats is almost a cantrip trasher, since SPs will draw extra Rats without problems.
2. Vineyards. Seems narrow, maybe a nice endgame move, but I cannot imagine feeling my deck with Rats that I cannot use from the go.
3. HoP and Fairgrounds for extra different names (I cannot imagine Menagerie working). HoP seems incredibly narrow, but maybe the best 8th card for the megaturn. Fairgrounds seems reasonable, although it would be an endgame purchase, almost a Victory card in a sense.
4. Hunting Party to reduce different names (reduce Coppers, Estates, Curses and Ruins into just Rats). This seems weak. Maybe to clear up Curses in an awful game like HP + Marauder. If it works, sounds like a nice find, but I cannot estimate its effectiveness.
5. Wishing Well and Mystic may have an easier time guessing. This seems like a total nombo, though.
6. Journeyman could have an easier way filtering. Again, sounds like a nombo.
7. Library will also filter better if we replace Estates, Curses and Coppers with Rats. Especially with non-drawing Villages, it could work. I imagine Rats being a nice mid-game addition to Festival/Library, to clear up and make room for the green.
From all of these, only 1 and 7 seem to me that are decen on themselves. Fairgrounds may have a room for Rats, but is just a dead $4 cost, if all the alternatives to reach 15 or 20 different names are expensive or Curses.