Dart +1

Darts +1 are magical enchanted darts doing more damage and are more accurate because of the +1 bonus to damage and thaco. Also, they are slightly faster than normal darts. Darts +1 are sold at X or can be found frequently while exploring Durlag's Tower.

In-game description
"The dart is a small, easily concealable missile weapon that is thrown rather than fired from a bow or other launcher."