VS mode is a multiplayer mode exclusive to the DS version of Super Mario 64. It allows up to four players to compete to be the first one to collect a star on a given map. There are four maps available.
To reach VS mode go to the main menu and select the orange VS icon on the left side of the screen. This DS will begin looking for other players. For VS mode, you only need one game card. The other players can use their Nintendo DS to download the game by going to DS Download Play from the DS main menu.
After everyone has tapped the "Touch to Start" button, then the map can be chosen. The person with the game card, or the person who started the session, will decide which map to play on. Press 
to reach the controller settings. Press 
to reach sound options and toggle the backlight on or off.
VS mode maps can be played in single player mode to practice.
Caps
Caps are special items available only in VS mode. Each cap is specific to one of the characters. If a character picks up a different cap (e.g. Mario picks up a Wario cap), then that character will transform into the one represented by the cap (e.g. Mario will turn into Wario). A transformed character takes on all of the new character's abilities. If a transformed character gets hit by another player, the transformed character will return to its original form.
Characters
Each character has special abilities in VS mode.
Castle Grounds
Sunshine Isles
Princess' Secret Slide
Battle Fort