A bad beat occurs when a player who holds a hand that can be called the underdog in the game come from behind to beat a hand that is well positioned and largely favored to win. This term is used to suggest that the person who wins the pot was in no way expected to be in the pot in the first place. This means that the eventual winner rode on the back of either luck or wits to catch up with the presumed winner who is also the one with the deck of cards favored to win that pot. During the course of your poker career, you are definitely going to encounter a lot of games with cases of bad beats.
So what makes a bad beat? Some of the following situations are the reasons for it: If a player had a hand that was not possibly expected to be a fold, that hand may be a loser. You could also lose in a game where the favored winner when your opponent turns a misplayed game to a stunning winner by stroke of luck. Poker players who are quick to tell stories of how good or terrible their luck was. These are often called "bad beat stories" and are taken lightly or otherwise depending on who is winning or losing. There are also "bad beat jackpots" attached to some types of poker games.