|Type(s)||Action - Duration - Attack|
|At the start of your next turn, +. Until then, when another player gains an Action or Treasure card they don't have an Exiled copy of, they Exile it.|
 Official FAQ
- While under this attack, whenever you gain an Action or Treasure that you do not have a copy of on your Exile mat, you Exile the gained card.
- Gaining a card that you do have a copy of on your Exile mat is unaffected, and lets you discard copies from your Exile mat if you want to as usual.
- Other abilities that happen when you gain a card happen at the same time, and you can only put the card on your mat if it has not moved anywhere since gaining it; so you can, for example, use a Sleigh to put a gained card into your hand, then fail to put it on your Exile mat.
- Gatekeeper only Exiles Actions and Treasures, it does not Exile, for example, Province.
- It only cares about cards in Exile, it does not care how they got there.
Gatekeeper is viewed as one of the weakest cards from Menagerie. $5 cost actions can be very powerful, and Gatekeeper's effect is often too slow and not effective enough to be worth the opportunity cost of buying a different $5 Action. It is strongest against cards that gain Actions of different names, such as Black Market, or Prizes from Tournament.
 English versions
|At the start of your next turn, +. Until then, when another player gains an Action or Treasure card they don't have an Exiled copy of, they Exile it.||Menagerie||March 2020|
 Other language versions
|German||Wache|| Zu Beginn deines nächsten Zuges:
+ . Bis dahin: Nimmt ein Mit-
spieler eine Aktions- oder Geldkarte,
von der er keine gleiche Karte im
Exil hat, verbannt er jene.
|Japanese||門番 (pron. monban)|
 Secret History