The Plasma Cannon is a weapon exclusive to Duke Nukem 64, the Nintendo 64 port of Duke Nukem 3D. Although the Plasma Cannon replaces the Freezethrower from Duke Nukem 3D, it is a completely new weapon that does not functionally resemble the Freezethrower or any other weapon. It has many unique features, but it is probably best known for dealing the most damage of any weapon in the game.
The Plasma Cannon fires plasma projectiles that deal moderate-to-high damage, depending on how long the cannon is charged before firing. Any enemy killed by the projectiles will visibly disintegrate.
Whether charged or not, all plasma projectiles explode upon impact. The resulting blue explosions are similar to other explosions in the game and can even blast through cracks in walls. Fully charged projectiles have a blast radius that is roughly four times the diameter of missile explosions. All other projectiles, regardless of their charge, have blast radii that are roughly half the diameter of missile explosions.
Without charging the cannon, the projectiles deal roughly 25 damage, short of the Assault Trooper's 30 hit points. When fully charged, the projectiles deal approximately 900 damage, short of the Battlelord Sentry's 1000 hit points. Although it does not deal the most damage per second, the Plasma Cannon deals vastly more damage shot-for-shot than any other weapon in the game.
One notable limitation of the Plasma Cannon is that it can be difficult to determine whether it is fully charged before firing. Visually, there is no distinction between being 90% and 100% charged, yet there is a profound difference in terms of the resulting blast radius. The player must learn through practice that there is a delay of a couple seconds before the cannon is fully charged.
Another strange feature of the Plasma Cannon is that, while the cannon is charging, Protozoid Slimers will be instantly destroyed on contact.
- Although the Plasma Cannon itself first appears on Incubator, the first appearance of its ammo is much earlier, on the secret level Duke-Burger.
- If a player activates the God Mode cheat after being killed by the Plasma Cannon during a multiplayer match ("Dukematch"), then that player will return as a completely black silhouette of Duke. This effect expires if the player is killed again by a different weapon.
- The Plasma Cannon looks and behaves similarly to the BMF Thunderstrike from Duke Nukem: Zero Hour and the BFG9000 from Doom.