The 4x100m Relay, pronounced "Four by One Hundred Meter Relay", is an Athletics event (specifically, Track) in the Wii version of Mario & Sonic at the Olympic Games. The game is a four-character relay race, which starts with the character the player picks. In Circuit mode, the additional characters are chosen at random. In Single Match mode, the player may pick the extra three characters in addition to their standard character.
The team switches every 100 meters by passing a baton. When a character's speed is locked, they can begin the next character's run by pressing B and hold the baton out to pass by pointing the Wii Remote frontwards. If the timing is bad, the switch will be slow and bad. But if the timing is just right, the person who takes the baton will be boosted.
To play this event, the player must hold the B button down at the start and then swing the wii remote down just as the announcer yells "GO"! Then the player must shake the wiimote and, if it is being used, the nunchuk. When the player is nearing the next teammate on the player's team, the player must press A to start the other player running and then swing the wiimote down very quickly with correct timing to pass the baton. The player must then use the wiimote to run once again. This action must be repeated four times, once for every teammate, and if the player is lucky, one of the members of the player's team will cross the finish line first winning the race for the player.
 Wii Version
Tails' fifth mission in the Wii version of Mario & Sonic at the Olympic Games is 4x100m relay and is the only event of all the characters in the game to be situated in this event. Tails is the only character with a mission in Mario & Sonic at the Olympic Games that has the event 4x100m relay. This event is rather easy for one Tails' fifth mission and two, the only mission in this event. To win it, Tails must cross the finish line at the end of the race before most of the other competitors, the other racers, cross the finish line at the end of the race but a little difference to the main course often taken is situated in this event. Instead of first, Tails must come in seconds, after the first place player and before the third place player. If Tails comes in any place other than second, he will lose the mission even if he comes in first and wins the race as the missions goal is to finish in specified placing, the specified placing being second. If Tails arrives in first or any place third or below, he will lose the challenge though that does not necessarily pertain to the race as if he comes in first, he will win the race.