The saying "bring it on" is a lengthened version of “bring it,” basically meaning “I’m ready,” or that the speaker is confident in his or her ability to win a challenge. For example, when someone says, “I can score better on this test than you,” the challengee might say, “Bring it on!” in response. This slang idiom can be said in a playful manner or as an encouragement to violence. An infamous version of the phrase was said by former United States President George W. Bush in response to militants in Iraq attacking U.S troops. In popular culture there is a movie with the same name, featuring competitive cheerleaders who encourage their opponents to bring it.
There are several versions of "bring it on," including “bring it,” “bring them on,” and “bring your stuff.” Other variations of the saying are “show me what you’ve got,” “do your worst,” and “go for it.” They all essentially mean the same thing and can be used in a variety of informal situations. It is not always used as a friendly challenge; in fact, "bring it" is often followed by profanities or insults when said during conflicts. In general, it is not used in formal situations where people might simply say “I accept your challenge” or “I can do this” instead.
In 2003, George W. Bush encouraged militants in Iraq to attack U.S troops by saying “bring them on.” His speech was meant to convey that U.S troops are tough and could take whatever was thrown at them. Overall, his speech was meant to instill hope that Iraq would eventually be a free country run by Iraqis and that the United States would not withdraw until the job was done. The speech and especially the term “bring them on” was very controversial, however, because the U.S. troops were in a dangerous situation.
The movie Bring It On, also known as Cheers! in Japan, is sometimes credited as the origin of the saying, but it only served to further popularize it. Experts have failed to determine the exact origins of the phrase because it is an incredibly common slang term. Some people speculate that it started in the combat sport boxing. Boxers used to say “bring him on” to accept a challenge. It is also not known where in the world the phrase originates, even though it is commonly used in North America.