Double weapons generally fire a pair of shots simultaneously, one forward, one in another direction. In most Gradius titles, a given source cannot fire another volley until both shots have disappeared, taking away dependability and power. Most double types are utility weapons that should be switched away from when their purpose is served, though some exceptions exist.

Types

• Double: The extra shot goes 45 degrees upward. It appears in almost every Gradius game on the default type/ship. Upward firepower that can ease the difficulty of certain stages.
• Tail Gun: The extra shot goes 180 degrees backward. Some stages have many enemies that attack from behind, making this ideal for them.
• Vertical: The extra shot goes 90 degrees straight up. For reaching entrenched targets directly above. (Gradius III and Gradius V)
• Free Way: The extra shot goes in the last direction you moved in, being able to fire in one of 8 directions. Awkward, but can replace your main weapon and is extremely versatile. (Gradius III arcade version and Gradius V)
• Spread Gun: Fires two shots in a spread pattern, and can be upgraded to fire three. A sort of pseudo Ripple Laser. In Gradius V, it acts similarly to the V Vulcan from Silpheed: The Lost Planet. (Gradius III arcade version and Gradius V)
• Back Double: The other shot goes 45 degrees backward. (Gradius III SNES)
• Twin Cannon: Kind of like the Twin Laser in other games, except the projectiles are normal shots. (Interstellar Assault)
• Wide Shot: Fires a wide-coverage shot spread. Based on Raiden's Wide Vulcan. (Gokujō Parodius SNES)
• Round Laser: Upon firing, a growing circle laser surrounds the ship. Still fires a regular bullet at its debut. (Gradius Gaiden and Salamander III)
• Auto Aiming: The extra shot targets enemies from front to back, with the shots disappearing at a certain distance. Fires a regular bullet.
• V-Shot: A shot goes up and another goes down. (Gradius ReBirth)
• Mind Blast: A triple shot that fires forward. (Solar Assault exclusive)
• Down Double: Fires a second shot downward. (Nemesis 3 exclusive)
• Nen-Do-Ha: Fires 3 wave shots in a similar fashion to TwinBee's Triple Wave plus erases circular enemy shots, Exclusive to Gesshi Hanafuma. (Otomedius Excellent)

Trivia

• The Twin Cannon and the Tail Gun are similar to Twin Shot and Back Shot in Thunder Force III.
• The behavior of Nen-Do-Ha when upgraded is akin to Wide Shot and Mega Flash (weapons used by Fire LEO-02 "Exceliza") in Thunder Force II.
  • The nature of V-Shot is similar to Side Blaster (also used by Fire LEO-02 "Exceliza"), though it replaces the main weapon.
• During the development of Gradius III, there are many more planned Double weapons that did not make the final cut with some being repurposed in later games (e.g. Rolling Missile was planned as a Double weapon) while others bare some resemblance to other iconic weapons from past or future games (e.g. the planned 5-way double weapon bares a superficial resemblance to the Wide Vulcan found in the Raiden series).