Do all Reaction cards completely block all Attack cards?

Question

I'm about to start a Dominion-day and need a question answered.

Do ALL reaction cards completely block all attack cards? i.e. does Tunnel block Witch?

Answer 1

Reaction Cards:

No. It's not an inherent property of Reaction cards that they protect you from attacks. What makes a card a Reaction is that it's used outside of the normal game sequence when something happens; they don't have to interact with attacks at all.

Moat protects you from attacks because it says it does. Tunnel gives you Gold when discarded, whether or not that is from an attack. Secret Chamber is revealed when an attack is played, but doesn't protect you from it; it just lets you manipulate your deck to attempt to lessen the blow.

Answer 2

Moat is the only Reaction card that blocks attacks. The only other card in the game that blocks attacks completely is Lighthouse, an Action - Duration card from the Seaside set which blocks attacks as long as it's in play (i.e. until the end of the turn after you play it).

Having said that, every Reaction card in the game except Fools Gold can be used in response to specific kinds of attacks:

Any Attack:

• Moat (Base). Completely blocks the attack.
• Secret Chamber (Intrigue). Before the attack, draw two cards then put two cards back on top of your deck.
• Horse Trader (Cornucopia). Before the attack, set Horse Traders aside. At the beginning of your turn, put Horse Traders back in your hand and draw a card. Since this card is no longer in your hand, it changes the number of cards affected by Militia, Ghost Ship, Goons, and Followers... and may cause the attack option of Minion to not affect you.
• Beggar (Dark Ages). Before the attack, reveal and discard Beggar to gain two Silvers, putting one of them on top of your deck.

Gain a card (meaning you can do it for each card from Montebank):

• Watchtower (Prosperity). You can choose to trash the card you're gaining.
• Trader (Hinterlands). You can choose to gain a Silver instead of the card you'd normally gain.

Discard cards:

• Tunnel (Hinterlands). If you discard this card to an attack, you gain a Gold.

Trash cards:

• Market Square (Dark Ages). Reveal and discard Market Square to gain a Gold.

Answer 3

Most defense reaction cards are returned to hand after each use as a reaction, and so possession prevents the attack card from affecting you.

Not all reaction cards do this, however. A few have other effects that result in either discarding or trashing the reaction card, which means they can only protect you from the first attack.

Further, not all reaction cards are defenses. One simply gives you a gold card when triggered.