When we are interested in slam in a suit contract but have a void in one of the side suits, it adds some complexity to our slam bidding. We may be able to make a slam missing two Aces (or a grand slam missing an Ace), if partner does not have the Ace opposite our void. When exploring slam, we want to know if partner has that Ace or has the “good Aces”, the ones opposite our losers. One way that we find out about the location of partner’s Aces is by using control showing bids. This is especially effective if we use them to show first round control (if we play that our control showing bids could be 1st or 2nd round, then we know less about which Aces partner hold). There is a gadget that we can use in some auctions that allows us to try to solve this problem. This convention, called Exclusion Keycard, asks partner for their number of Keycards (or Aces if we play Blackwood), excluding one particular Ace – the place where we are void. This Exclusion allows us to find out if partner has enough of the “right Aces” for us to make slam.