Some actions can be counter-acted. If another player tries to perform an action and you want to block that action, you can use one of the counter-actions as follows:
• Claim the Duke to block another player's Foreign Aid.
• Claim the Contessa to block an Assassinate targeting you.
• Claim the Ambassador or Captain to block a Steal targeting you.
You must announce your counter-action after any challenge to the action has been resolved.
Like character actions, each counter-action depends on having a particular card. When you announce a counter-action, you are claiming that you have that card. You can be challenged on that claim, just like with character actions. But if you are not challenged, or if you are challenged and win, your counter-action automatically succeeds.