Deception means deliberately making someone believe something that isn't true. When you practice deception, you're trying to trick or mislead another person on purpose. A magician uses deception to make you think a coin has vanished when it's really hidden in their palm. A student practices deception by claiming they turned in their homework when they actually forgot to do it.

Deception is different from an honest mistake or misunderstanding. If you accidentally give someone wrong directions because you misremembered the street name, that's not deception. But if you send a rival team to the wrong field on purpose so they'll miss the game, that's deception.

People use many forms of deception: hiding the truth, making up false stories, pretending to be someone they're not, or leaving out important information. A clever deception might fool people temporarily, but most deceptions eventually unravel.

While harmless deception exists in magic shows and surprise parties, serious deception destroys trust. Once people discover you've deceived them, they question everything else you've said. A person who practices deception regularly is called deceptive or deceitful, someone whose word you can no longer rely on.