A darkened practice room aboard the Enterprise-D where officers keep up their marksmanship by firing hand phasers at moving points of light.
The phaser range is the Enterprise-D's small-arms practice room. One or two people stand on a platform in the dark while the computer throws up brief coloured targets around them at a chosen level of difficulty, and it keeps score of the hits.
The room tends to be used for conversations that need privacy. In A Matter of Honor, Picard and Riker shoot together while discussing the officer exchange programme, and the talk ends with Riker volunteering to serve on a Klingon ship. In Redemption, Guinan joins Worf at the range, quietly outshoots him and uses the moment to make him think about his son and his place among Klingons.
Security officers are expected to qualify there regularly, and Worf treats the high scores as a matter of professional pride.