Checkpoint Flag (or Midway Flag) is an object that signifies a checkpoint in many Mario games. They are similar to the Midway Gates in Super Mario World. When Mario or Luigi lose a life, they will restart at the Checkpoint Flag.
 Game History
 New Super Mario Bros.
They first appear in New Super Mario Bros. as white flags with a Mushroom on them.
 New Super Mario Bros. Wii
They would reappear in New Super Mario Bros. Wii and appear as black flags with Bowser's symbol on it. When touched, it will change color to what character touches the flag. They will also receive 2000 points. It will also turn Mario from Small Mario into Super Mario.
 Super Mario Galaxy 2
In Super Mario Galaxy 2 they feature the same appearance and function the same as they did in New Super Mario Bros. Wii. When Mario or Luigi touch the flag, they turn into a "M" or "L" symbol. Depending on the galaxy, they can appear anywhere in the Galaxy and sometimes a few of them will appear. They are positioned near the start and end of the level. Some Galaxies won't have any Checkpoint Flags.
 Super Mario 3D Land
Checkpoint Flags would have the same appearance as the ones from Super Mario Galaxy 2 in Super Mario 3D Land. They would turn Small Mario into Super Mario and serve the same purpose as they did in the past games.
 New Super Mario Bros. 2
Checkpoint Flags appear in New Super Mario Bros. 2. They would give a player 2,000 points when touched and will replace the Bowser symbol with an "M" or "L" symbol depending on the Mario Bros. During Coin Rush, when the flag is touched, it will add 50 or 100 seconds to the timer.