The Wave Beam is a Chozo weapon left behind on the planets Zebes and SR388 to aid Samus in her quests. It gives Samus's beam the ability to pass through walls, hitting viable targets on the other side.
The Wave Beam fires energy waves capable of penetrating walls and reaching otherwise unreachable targets. Its earliest incarnations depicted it as one oscillating beam following a helical pattern, giving it a wider damage range than the Power Beam.
In Fusion and Zero Mission, however, Samus and the SA-X fire a very large blast with every shot. Combining the Wave Beam and the Plasma Beam in Super Metroid splits Samus's Plasma Beam into two shots.
The SA-X uses the Wave Beam combined with both the Plasma Beam and Ice Beam.
In Metroid, Samus must choose between Beams to carry at a time. She can find the Wave Beam in Norfair.
Metroid: Zero Mission
Metroid: Zero Mission grants Samus stackable Beams. Unable to bypass a Kiru Giru larva, Samus must navigate her way around it to find the Wave Beam in Norfair. She now is given the ability to attack the weak underside of the larvae, normally hidden behind a thick shell, permeable to the Wave Beam.
Super Metroid plants the Wave Beam in Norfair once again, requiring the Grapple Beam to reach. Here, it can be combined with some combination of the other beams available.
In Sector 2 (Cryosphere) of the Bottle Ship, Super Zebesians trapped Samus in a glass cage, and they were able to fire their Wave Beams inward toward Samus, but she was unable to retaliate. Adam authorized use of the Wave Beam, making the Super Zebesians easy targets.
Metroid: Zero Mission
"This beam, which is made up of energy waves, can pass through solid objects."
Metroid: Other M
"Effect: Increases damage.
Secondary effect of penetrating materials that are transparent or semitransparent."
- "The Wave Beam sends out a charge in a wavy pattern and pierces some obstacles." Super Metroid Instruction Booklet, Pg 23
- "This beam, which is made up of energy waves, can pass through solid objects." —Inventory Data (Metroid: Zero Mission)
- "The beams are wave-shaped and are stronger than normal beams. If you already have a long beam, the long beam becomes a long wave beam" Metroid Instruction Booklet, Pg 23
- "This allows Samus to fire beams of energy waves that can penetrate walls." Metroid: Zero Mission Instruction Booklet, Pg 25
- "The beam travels in a wave shape. It is a very powerful beam and has a wide range of effect." Metroid II: Return of Samus Instruction Booklet, Pg 21
- "Adds the ability to penetrate transparent and semi-transparent objects. This powerful beam can also be shot as a Charge Beam." Metroid: Other M Instruction Booklet, Pg 23
- "Shoot through obstacles with this undulating beam." Metroid Fusion Instruction Booklet, Pg 32