Flagging in chess refers to the act of winning (or drawing) a game on time. It is more common in blitz and bullet games since players often get in time trouble in faster time controls. The term flagging is an allusion to analog chess clocks that have flags in their displays that fall whenever a player runs out of time. If a player runs out of time, it is their fault, and flagging is not considered unethical in chess. In fact, flagging can be an important strategy in fast time controls, and learning how to take advantage of the clock can be a powerful weapon when playing online. However, it is important to note that flagging opponents should not be used every time, and it is not considered a skill. It is also important to have good time management skills to avoid getting flagged when in a better position.