The dart is a throwing weapon and a common item of equipment in many Fantasy Role-Playing games.
Your standard RPG dart looks like a very short arrow, but it is much heavier to allow it to be thrown rather than fired. The often look pretty similar to jarts or lawn darts.
The dart is the number one anti-spellcaster weapon. Its very high rate of fire allows a good chance of disrupting a wizards spell before he can successfully cast it. While this weapon is also popular with many wizards, as it allows them to be effective in combat even if they have no spells to cast. The dart as a primary weapon also helps to keep the unarmored wizard out of the middle of the battle, unlike the more popular dagger and quarterstaff, which puts the fragile wizard right in the thick of things.
Darts are also a popular weapon among the lizard man tribes of the various AD&D worlds. Where it is also used as a hunting weapon.