A preempt or pre-empt is a bid made in order to take up opponent's bidding space so that they cannot find the optimum contract. Weak two bids and suit opening made at the three level or above are preemptive openings. Preempts are made by length rather than strength. The law of total tricks gives a good indicator on how high to preempt. Preempts are rarely made at the pass-out seat, since there is no one to preempt.