Nintendo recently patented a Rumble-Stylus System for a handheld.

“A game apparatus includes an LCD, and a touch panel is placed on a top surface of the LCD. A player instructs an enemy character displayed on the LCD by use of a stick to attack the enemy character. For example, in a case that the enemy character exists at a depth of a game screen, little damage is applied to the enemy character, and a weak vibration is applied to the game apparatus. Conversely, in a case that the enemy character exists at a front of the game screen, much damage is applied to the character, and a strong vibration is applied to the game apparatus. In either case, the vibrations are transmitted to the fingers or hands of the payer via the stick.”

According to this tidbit copypasta’d from the source…. I can hardly make out the first part, but I believe that the stylus makes the vibration. If the character is, for example, heavily damaged, than a strong vibration is applied. Vice-versa. Correct me if I’m wrong.

Source: My Nintendo News.