APPARENTLY, BEN JOHNSON scared off an intruder the other day by waving a pistol in his face. OK, it was a starter's pistol, but the intruder didn't know that.

Obviously, being the subject of world scrutiny, not to mention scorn, is wearing thin on the Canadian sprinter who still has about 710 days remaining on his two-year suspension for being caught with steroids in his system.There hasn't been anyone so roundly vilified since Idi Amin. He isn't in jail, but he might as well be. He is being put to ridicule and shame.

"How far we have fallen," said an editorial in the Toronto Globe & Mail, as reprinted in Sports Illustrated. "National celebration has become national wake. Parents struggle to answer questions from their teary-eyed children."

It's been like that since two weeks ago, when Johnson was found guilty of having the anabolic steroid stanozolol in his system after running the 100 meters in the Summer Olympics in Seoul in a now defunct world-record time of 9.79 seconds.

Conversely, the reaction to Jay Howell has been quite different.

Howell was caught with pine tar in his baseball glove - the better to grip the ball with - during a playoff game between the Los Angeles Dodgers, the team he pitches for, and the New York Mets. Howell was suspended for the rest of the game, and for one more game, and then had his sentence reduced so he could still help his team in the playoffs. The commissioner of the National League said it was in the best interest of the fans, who clamored for Howell's quick return.

Both Johnson and Howell had been caught cheating. But the hardly similar reactions to their crimes provided a rather dramatic essay on the wide variation that exists in the world of sports between right, wrong and what you can get away with and still stay popular and keep your endorsement contracts.

This is not a simple subject. The rules vary from sport to sport. In the interest, therefore, of keeping up with the times, and of putting this current wave of interest in steroids in perspective, here is a brief sport-by-sport primer on cheating in the '80s. What's OK and what's not OK and what's in the middle.

Track & Field: Since athletes and doctors seem to agree that 50 to 60 percent of all athletes cheat by using some form of performance-enhancing drug - out of testing, that is - it's obviously socially acceptable to cheat. But it is not socially acceptable to get caught. Getting caught means you got the wrong advice from your doctor and didn't get off the stuff on time and reflects poorly on your ability as an athlete to train properly by choosing the right aides.

Football: Performance-enhancing drugs - steroids mostly - are all systems go. Literally. In the NFL this seems to be particularly true, where the league doesn't test for steroids and looks the other way as linemen, who are big to begin with, turn into human wrecking machines that make Ben Johnson look like a pipsqueak. Also, amphetamines, like caffeine, are A-OK. No one says much about the fact that this rampant drug usage might be why NFL veterans hit old age at about 48, and, on the average, have more health and heart problems than people who live in nuclear war zones. The NFL does come down hard on cocaine, heroin and other illicit drugs that harm a player's attendance and also hurt the gate.

Basketball: Performance-enhancing drugs don't seem to be as big of a deal in basketball, probably because they haven't found any that dramatically increase your vertical jump, your hang time, or your ability to stick the 15-foot J. The only real cheating seems to lie with recruiting (in college ball) and the zone defense (in the NBA). Either are perfectly acceptable if you don't get caught, and if you do.

Baseball: Here is the sport for those with real larceny in their hearts. The baseball credo seems to be: Whatever you can get away with, more power to you. Cork in bats, sandpaper in the rim of pitcher's hats, K-Y jelly in the palm of your glove, stealing signs - hey, it's all OK. The Hall of Fame is loaded with spitball pitchers proud to tell about it. Like with football and basketball, the only seriously frowned-upon drug abuse is with the hard stuff that also carries a prison term.

So anyway, that's briefly the way it is. And if Ben Johnson, who is just sitting around now for two years with nothing else to do, is getting a little tired of his role as a worldwide villain, maybe it's because he turned on the TV and saw Howell back on the mound, or the NFL Game of the Week, or track people racing who have great timing, if you know what he's saying.

Maybe the old line that goes "Winners never cheat and cheaters never win," has him - like a lot of people - more than a little perplexed.