A one up, also known to as an extra life or "extra man", is a common video game term for an extra chance to play the game. The more compact term "1-up" is the more common form in the games themselves. One-ups are very frequent in platform games and common in other action-heavy games. Highly often, "extra life" is literally true. If the player character is killed extra lives allow the player to return, unscathed, for another try.

1-ups are usually collected as items or earned through specific accomplishments. One is usually the ultimate reward, and difficult to obtain. Many games give one-ups as a reward if enough (usually 100) of a certain object can be collected, such as coins, rings, or diamonds. On some occasions it is surpassed by an even rarer extra continue, which awards a whole new set of lives instead of just one - very much like adding a credit in an arcade game. One-ups often take the form of icons of the main character's head, or other such represenations such as dolls, coins, hearts, ankh symbols or mushrooms. A simpler icon of just the letters "1up" is also common.

Some games feature items that award more than one life at a time. They are usually referred to as 2-ups, 3-ups, 5-ups, etc.

If the player loses all extra lives and continues, a game over will be experienced.

The term comes from Japanese katakana-English. "~ UP" (Japanese: ～アップ) means "to raise the ability of, to increase." Some English study books in Japan have phrases like "Ability UP!" written on their covers. This Japanese shortening of English has provided us with another popular gaming phrase, level up; though Dungeons and Dragons aficionados may disagree about the origins of this oft-invoked phrase.