Samus's Arm Cannon is her primary offensive tool, capable of firing various Beam Weapons. Unlike previous Prime games, Metroid Prime 3 features a stacking Beam system, where new Beam upgrades enhance your existing weapon rather than replacing it. This means your primary Beam becomes more powerful and gains new properties as you progress.
- Power Beam: Your default weapon. Fires rapid energy shots.
- Charge Beam: Hold 'A' to charge a more powerful shot. Essential for dealing significant damage and solving certain puzzles.
- Plasma Beam: Acquired on Bryyo. Adds a fiery component to your Beam, allowing it to melt ice and deal extra damage to organic enemies.
- Nova Beam: Acquired on Elysia. Adds a powerful, piercing component to your Beam, allowing it to penetrate certain armored defenses and activate specific energy conduits.
Each Beam upgrade also enhances your Charge Beam, creating devastating Beam Combos. Experiment with charging your shots after acquiring new Beam types to discover their full potential. Switching between Beam types is done via the D-Pad, though the stacking nature means you'll primarily be using your most advanced Beam.