Hey everyone, here's another card idea I've been thinking about.
Siege Engines
Action
Cost: $4
+1 Action
Each other player must discard a reaction card or reveal a hand with no reaction cards.
If no player discarded a card, +2 cards, then discard one card from your hand.
The first thing to notice about this card is that it is NOT an attack. Like masquerade, it feels like an attack in that it forces your opponents to discard reaction cards, but it can't be defended against with cards like moat or horse traders because it itself isn't an attack card.
The next thing to notice is that it will play quite differently depending on what other action cards are in the kingdom. A lot of the time it will show up in kingdoms without any reaction cards. In this case its a relatively vanilla sifter, somewhat comparable to warehouse or oasis. I think its certainly powerful at $4 since its basically a laboratory as long as you have a victory card in hand to discard, but I don't think it would be too strong for its price point.
I originally designed this card however thinking of its use in kingdoms with good attack cards and reaction cards which effectively block the present attack cards. In this case Siege Engine serves as an enabler for your attack cards, allowing you to play the Siege Engine first, discard your opponent's moat, and then have an action to play your attack card on your defenseless opponents! If you have the bad luck to draw multiple Siege Engines but no attack cards, your Siege Engines' sifting ability gives you a chance to draw your missing attack cards to complete the combo.
All in all I think its a neat card that opens up some unique possibilities for reacting to the way your opponent is building his or her deck in games with reaction cards.
It also has a really weird/hilarious interaction with Tunnel.