It has been many years since any bridge author attempted a comprehensive description of preemptive bidding, and much has changed in the interim. Modern players open the bidding on lighter values, and preempts, formerly based in at least a semblance of sanity, are now made on the flimsiest of excuses. This is a comprehensive treatment of preemptive bidding – not just when to open and with what, but the issues surrounding constructive and obstructive bidding in the subsequent auction.