Bivouac's reaction is a bit strange. So the way I read it, you don't have the option to just reveal it, like you do with Horse Traders or Watchtower, right? Rather it needs to get revealed by something else. But the rules don't specifically define when such a thing would trigger... do you intend for it to trigger anytime an effect says "reveal", and it is one of the cards that is shown to your opponent's this way? Or do you intend for it to trigger anytime the card becomes visible to your opponent?
The reaction is meant to trigger only when another card makes you explicitly "reveal" it. I'm trying to think of a wording that would make that very clear. Maybe I will just phrase it like "When another card makes you "reveal" this Bivouac,..." - the quote signs are uncomely, but it should be clear this way.
So for your examles the following applies:
You play Sage. As you are revealing cards, you reveal Bivouac. I'm sure the card allows you to react in this case.
Opponent plays Cutpurse. You have no Copper, so you reveal your hand. Bivouac is in your hand. I assume you can use the reaction now, but not 100% sure.
You can trigger the reaction in both cases.
You play Library. As you are drawing cards, you set aside a Bivouac. Can you react now? Nothing said "reveal", but the card was indeed revealed in that your opponent's can now see it.
During cleanup you discard your hand, and your hand included a Bivouac. You put Bivouac on top of the discard pile, so it in now revealed to your opponent. Can you react? (If so, that's a pretty strong ability).
You play Bivouac. When you need to discard a card to it, you discard another Bivouac. That second Bivouac is now revealed, so can you react? (If so, this card is VERY strong, since having another one in hand makes the first one as good as regular village).
As playing the card as an action does not trigger the effect, so does not discarding the card at any time or setting it aside. I should have thought about that. Like Hinterlands or Dark Ages, this set would need to come with some additional rules clarifications as to when a card is "revealed".
Suburbia... the way it is worded now, you can trash 1 card, then reveal Suburbia from your hand 30 times to draw 30 cards. You are always allowed to reveal the same reaction card multiple times to the same event. Cards like Horse Traders prevent this by having you set it aside, so you would need to do something like that.
You have a good point. Of course you should only be able to reveal the card once per trashing. But how do I phrase that? I do not want the card to be discarded from your hand when you use the reaction. Maybe have it set aside and returned to your hand
after the trashing? Or just an Outpost-ish phrase like "You may only reveal this once per card trashed or returned."
Town Portal A looks extremely weak. Without having other Action-Victory cards, or Vault/Cellar/Warehouse/Secret Chamber/Crossroads around, then the action seems to be 99% worthless, so it may as well just be 2VP for $4 (which you would still buy sometimes, but just as a regular VP card).
I like to think of it this way: $4 for 2VP may not be a good ratio but at least the card
does something, other than most other VP cards at $4 or $5. Scout does a similarly bad thing that only helps you in rare cases with specific cards in the kingdom. But Town Portal A is at least worth 2 VP. While still pretty weak, I would buy it over Scout any day.
Town Portal B seems very strong. WAY better than Great Hall at $4 instead of $3. 2 VP instead of 1, and the action is quite strong if you have several Town Portals in your deck. Basically, as long as you have at least 1 in your discard pile, playing 1 is as good as a Laboratory.
Yes, it's one of those cards that you don't want your opponent to get all 8/10/12 copies of, like Minion, Knights, Gardens, Tournament etc.. However, as you wrote, the Lab effect is conditional. There need to be other City Portals (or Great Halls, Nobles, Harems) in your discard pile, and any time you didn't draw a victory card from your discard pile with it, it's just a cantrip. Also, it's not technically a Lab variant, because you do not cycle 2 cards, but only 1. The second card, if there is one, is recycled from the discard. Playtesting will bring more clarity, hopefully. If anything, I might reduce the VP to 1.
Slurry Pit... I think another Masquerade-thing is a good idea. But note that the rare case of playing Masq when you or an opponent has 0 cards to pass will be a little more common here... as long as their discard pile is empty, they can't pass a card. And if you play it with an empty discard pile, you steal a card from them without giving anything back. It can't pin like Masq can, but it can still "trash" all the cards in their discard pile.
I think passing all your junk to your opponents is not a big problem with Slurry Pit, because they can easily return the favour the turn after. You have a good point with the "stealing" issue, however. I might add the condition that you need at least 1 card in your discard pile to make the action work. But then I would need to shorten the text in another place so it won't get too wordy.
The cards I didn't specifically mention, I like just fine. As a whole I agree with Scott that the returning to the supply is just a worse version of trashing (not worse as in weaker, but worse as in less good or fun for the game). I think it's fine if they just trashed instead. But I think there's some really good ideas in here!
The latter is great to hear
I plan to make cards that specifically care about the supply piles that should have some (hopefully fun) interaction with the returning actions. For example an inverted City that gets weaker the more piles are empty. If it turns out, I cannot make any interesting stuff with it, I might change it all to trashing. But for now, it's too early to decide.
