Plasma Pistol

Description
The Plasma Pistol is the game's "default" weapon. It is a blue and gray pistol with a heat indicator on the back of its slide. It does not feed from an ammo pool, as it has an infinite supply.

Besides the Plasma Pistol, there are the Blast Pistol and the Laser Pistol, which have to be unlocked first. A pistol box will contain a random pick among the pistols that have been unlocked at this point.

Mechanics
The Plasma Pistol can be found in multiple rooms in every level, including the entry lobby, behind a glass panel labeled "Emergency Firearm." The elevator entryway of every level has at least one of these glass panels.

The pistol is intended to provide the player with a basic weapon, though despite being the most common weapon in the game it is still an excellent fallback weapon in emergencies. It has infinite ammunition, though rapidly firing it will overheat it, forcing it into a cooldown state for roughly two seconds. It isn't particularly powerful, but can still one-shot humanoid enemies when hitting them in the head in all difficulties except hard. It is also fairly accurate for a pistol, and its sights facilitate aiming quite well.

The Plasma Pistol's biggest drawback is its inability to sustain damage, especially on heavily armored targets like the robots found in later levels.

Tactics
The Plasma Pistol should always be kept as a backup weapon until you come across a more reliable sustained-fire weapon like the Assault Rifle or Bouncer Shotgun. Its infinite ammunition means you never have to worry about being forced to reload in the middle of a firefight as long as you exercise enough trigger discipline to avoid overheating it.

It's important to note that if you dual-wield pistols (Plasma Pistol and Laser Pistol), they share heat. This not only prevents you from rapid-firing them without rapidly overheating, but also prohibits you from holding one in your off-hand to fire when your main hand overheats, as both pistols will overheat at the same time.

Trivia

 * This pistol makes a “guest” appearance in the VR game Hot Dogs, Horseshoes, & Hand Grenades.