Any wrestler using a non-regulation object as a weapon against his opponent is subject to immediate disqualification.
What's The "Wrestling Reason" For This Rule Existing?
This one should be obvious but a wrestling match is a test of wrestling skill between two men or two teams of men. There is no tolerance for chairs, belts, kendo sticks, ladders, tables, ring bells, garbage cans, cookie sheets, baseball bats, fire extinguishers, TV monitors, brooms, sledgehammers, mannequin heads, cinder blocks, ring posts, chains, or any other outside objects.
Note: For a short time in WCW in the early 1990s, WCW executives were worried that the term "foreign object" would be deemed offensive by some viewers. It was never mentioned which group could possibly be offended by the term "foreign object" but, because of this, WCW started calling these items "international objects" which sounds stupid even 20 years later.
What's The Real Reason?
Before the rise of ECW, and therefore the rise of the Attitude Era, weapon matches and hardcore matches were very few and far between. They were used about as often as cage matches (meaning hardly at all) and were only brought out to settle a major feud once and for all.
Thanks to the late 1990s, fans started expecting to see hardcore matches on every single show. In ECW, every single match was a hardcore match with no rules whatsoever. The World Wrestling Federation created the Hardcore title and WCW followed soon after. Suddenly, the wrestling world was saturated with guys delivering unprotected chair shots, matches filled with weapons, and Spanish announce tables that were broken on a daily basis
The problem with this is that audiences got used to seeing them. Once you get used to seeing something, you're no longer entertained by it. Jim Cornette described it as seeing two dogs humping on the sidewalk on your way to work. The first time you see the dogs, you think it's the funniest thing you've ever seen and can't wait to tell everyone about it. However, if you see the same two dogs humping in the exact same spot for 4 months, it's no longer entertaining and you no longer care.
Hardcore wrestling shortened the careers of countless wrestlers and caused too many injuries to count. Chairshots and bloody brawls were no longer special, there were commonplace. Wrestling isn't a bloodsport, it's supposed to be an athletic competition.
However, thanks to WWE's brand of "sports-entertainment", we are no longer watching professional wrestling. With a few notable exceptions, we are now watching actors who view wrestling as just another role. Swimsuit models who couldn't tell you who Lou Thesz is are sleepwalking through boring matches wondering if they are going to get a phone call to star in The Expendables 8 instead of thinking about psychology.
Professional wrestling is a dying art and the lack of rules and consistency is going to be the cause of death.