How does the bidding auction work in skat?

In the card game skat, the bidding auction determines which player becomes the declarer. Players do not bid on specific contracts; instead, they bid on the potential game value (score) of their hand.

The auction proceeds as follows:

• Roles: Players are designated as forehand, middlehand, and rearhand, starting from the dealer's left.
• Sequence: Middlehand initiates the bidding by naming a game value (starting at 18). Forehand responds by either accepting the bid (if they can match or exceed it) or passing.
• Progression: If middlehand passes, rearhand may bid against the survivor. If a player passes, they are out of the auction.
• Outcome: The last player remaining becomes the declarer and must play a contract with a value at least equal to their final bid.
• Passes: If all players pass, the deal is annulled and passes to the next player.

Once the auction concludes, the declarer announces their chosen contract—such as a suit-trump game, a grand bid, or a null bid—ensuring the chosen game meets or exceeds the value of their winning bid.1