Usage

• The term "phaser" stands for phased energy rectification, and Starfleet personnel use phasers in place of guns. Phasers fire beams of energy and can be set to various power levels. They can be used to stun an opponent, kill an opponent or disable other ships. The most powerful phasers can drill into planets. The two categories of phaser are personal sidearms and ship-mounted weapons. Each type has several models of differing power levels.
  
  

Sidearms

• The most powerful phasers that Starfleet personnel carry are type-3 phasers, called phaser rifles. These weapons have 16 settings and can be programed to fire at more than one target. They also can be adjusted to shoot a pulse of energy that expands as it travels, disabling lifeforms while leaving equipment undamaged. Starfleet personnel seldom use type-3 phasers; they consider such powerful hand weapons to be overkill. Most personnel carry type-1 or type-2 phasers instead.
  
  

Phaser Banks

• The Enterprise regularly uses its phaser banks to defend itself.Mario Tama/Getty Images News/Getty Images
  
  Phasers mounted on ships as part of their defense systems are called phaser banks. The most powerful phaser banks use type-8 phasers. Ship-mounted phasers are the most common means of attack and defense for ships; they also can be adjusted for non-martial purposes, such as drilling into planets. The energy emitted by shipboard phasers is powerful enough to travel 300,000 kilometers, or about one light-second.
  
  Shuttlecraft are too small to carry the most powerful phasers, but they sometimes carry type-4 phasers, which are of medium size and medium strength.
  
  

Episodes

• Type-3 phasers appear only once in "Star Trek," the original Star Trek television series. That was in the episode "Where No Man Has Gone Before." In the rest of the series, the crew avoided the most powerful phasers, considering type-1 and type-2 phasers sufficient. For the same reasons, phaser rifles don't appear until the fourth season of "Star Trek: The Next Generation," in the episode "The Mind's Eye."
  
  Type-8 phasers appear in the "Star Trek: The Next Generation" episode "Pre-emptive Strike," which aired during the series' seventh season.