Charlatan
$3 - Action/Duration/Attack
+1 Buy
Until your next turn, when another player buys a card, they choose a card they have in play and exchange it for a card costing at most the same as the chosen card with a different type. If they didn't, they return the bought card to the supply. At the start of your next turn: Gain a Silver to your hand.
I'm not sure "with a different type" is unambiguous in this context. I assume you can exchange a Chapel for a Moat, since Moat has a type which Chapel does not. But can I exchange a Moat for a Chapel, since Moat has a type which Chapel does not? If so, can I also exchange Moat for Moat, since Moat has a type that is different from one of Moat's types?
I think "with a different type" could be interpreted as any of the following:
1. B has a type which A does not have (I can exchange Chapel for Moat, but not vice versa)
2. A and B have mutually exclusive sets of types (I cannot exchange Moat for Chapel or vice versa)
3. A and B do not have exactly the same set of types (I can exchange Moat for Chapel and vice versa)
4. There exist different types x, y, such that A has type x and B has type y (I can exchange Moat for Moat)