There are twelve different types of weapons in Escape Velocity Nova, each with a slightly different effect, though some are quite similar.
Unguided Projectile[]
The projectile simply flies from the front of the ship in the direction of the ship's heading at constant speed, regardless of the speed of the ship, until its lifetime expires. This has the unfortunate effect that on some fast ships, the shots can be moving slower than the ship, making them appear to travel backwards. Still fires if no target selected. Examples: Medium Blaster, Light Cannon.
Beam Weapon[]
Fires a concentrated beam of energy in the direction of the ship's heading out to a fixed distance from the ship. Still fires if no target selected. Examples: Capacitor Pulse Laser, Polaron Cannon.
Homing Weapon[]
Missile homes towards the target vessel. Still fires if no target selected, but does not home (unless it becomes distracted by an asteroid or another ship). Examples: Etheric Wake Missile, Polaron Torpedo.
Turreted Beam[]
Same as for the beam weapon, but the beam fires in the direction of the target. Does not fire if no target selected. Examples: Ionic Particle Cannon, Summer Bloom.
Turreted, Unguided Projectile[]
Same as for the unguided projectile, but the projectile is fired in the direction of the target. Does not fire if not target selected. Examples: Medium Blaster Turret, Raven Rocket Turret.
Freefall Bomb[]
Bomb is launched at 80% of the ship's current velocity. The weapon detonates whenever a ship comes into range. Still fires if no target selected. Examples: Stellar Grenade
Freeflight Rocket[]
Missile is launched in the direction of the ship's heading, and accelerates to its maximum velocity. Still fires if no target selected. Examples: Raven Rocket, Stellar Grenade.
Front-Quadrant Turret[]
Fires in a ninety-degree quadrant centred on the direction of the ship's heading. If no target is selected, or if the target is out of the quadrant, the gun fires directly forward. Examples: Wraithii, Hail Chaingun
Rear-Quadrant Turret[]
Fires in a ninety-degree quadrant centered on the opposite direction to the ship's heading. Does not fire at all if no target is selected. Examples: none in default scenario.
Point-Defense Turret[]
Similar to the turreted, unguided projectile, but it automatically fires at any incoming hostile missiles or fighter craft. Cannot be controlled by the player, and fires only if a missile or fighter is in range, regardless of whether the player has a target selected. Examples: Quad Light Blaster Turret, Storm Chaingun.
Point-Defense Beam[]
Similar to the above, only it fires a beam rather than projectiles. Examples: none in default scenario.
Carried Ship[]
These are ships contained in fighter bays. Still launch when no target selected. Examples: Manta Bay, Create Dart.