Powerlifting is a sport in which you compete in the squat, bench press and deadlift, and the athlete with the highest total in his weight class is the winner. Like any other sport, you must properly peak for competition, and tapering your training volume is an important part of it. Consult your physician before beginning any exercise program, and ensure you are familiar with the rules of the organization you will be competing in. Most powerlifting competitions are held on weekends, with Saturday the primary day, and two-day meets running into Sunday.
You do not quit training a couple of weeks out and simply rest; you need to slowly reduce your training volume. If you are following a periodized lifting program, you should be prepared to execute your heaviest singles at the meet, and begin dropping your assistance work. Three weeks out is a good time to slowly limit exercises that you are not going to perform in competition. Do not drop everything, but if you are performing four assistance exercises for your squat, drop the hardest one first, and two weeks out cut the volume in half on the other two exercises. Two weeks out from the meet is the last time you deadlift.
The Last Week
In a periodized program, where you slowly increase intensity and decrease volume, you should be ready to take your first and second attempts on the squat and bench press. If you are having trouble making weight, squat on Monday and bench on Tuesday, which will allow you to strain a little less in training if you are limiting calories. If your weight is on point, do all four lifts on Monday and call it a day. In between your singles, make sure you take three minutes to rest. This is the minimum time between lifts in competition.
If you are using a conjugated periodization training program, three weeks out you should be hitting at least 90 percent of what you want to open with on your first attempts with each lift, and the rest of your training should be unchanged. Two weeks out, work up to 95 percent of what you would like for your second attempts on each lift. Make this the last week you deadlift, to save your lower back. Monday of the last week out, take your first and second attempts in the squat with some light reverse hypers and possible abdominal work, and Tuesday or Wednesday hit your first and second attempts on the bench press.
Do not change your entire training program at the last minute before a meet; you have enough to focus on while competing. If you are having trouble making weight and this is your first meet, do not worry about it -- lift in the next higher weight class. You do not want to try to squat heavy while you are cramping from cutting weight; this risks injury. Skilled lifting such as powerlifting and weightlifting both have a lower injury rate than recreational lifting due largely to the planning that goes into them.