In Metroid: Zero Mission, the Pirate Alarm System is used on the Space Pirate Mother Ship and in the Chozo Ruins in Chozodia. If any Zebesian sees Samus Aran, the alarms are instantly activated. The music changes, red lights flash, shutters close, and Zebesians instantly enter the room from nearby doors and run after Samus. The alarm is not activated if Samus stuns the Zebesian with her fully-charged Paralyzer before it sees her.
The Space Pirates also have numerous devices that automatically trigger the alarm system. The first device that can set off the alarm was a visible green beam emitted by two small cylinder-like gadgets that, if breached, acts as a tripwire. Searchlights and floating-eye sensors can also trigger the Pirate Alarm System.
In Metroid Prime 3: Corruption, it activates when intruders are detected, followed by small antennas protruding from devices on the wall, flashing as they warn and summon Space Pirates to terminate the intruder. They are activated either by tripping laser devices or from small handheld alarms. Once the antennas are activated, Samus has a few seconds to shoot them until she runs out of time and is attacked by Space Pirates.
There is another device also found on the same planet that appear as pairs of towers which produce a beam invisible to all but the X-Ray Visor. Serving a similar purpose, it is part of the Pirate Alarm System and will alert nearby forces (in particular Commando Pirates) whenever Samus passed through it. Samus can avoid it by going into Morph Ball mode and moving beneath it.
Sometimes, when Samus is sighted, Space Pirates would run in and activate a beacon that sent a distress signal.
Command Courtyard scans
- "Pirate Alarm System. Alert beacon is retracted. No threats detected."
- "Pirate Alarm System is sending a distress call. Shoot the beacon to reset the alarm."
- "Pirate Alarm System has alerted security. Hostiles are en route to this location."
- In Metroid: Volume 1, a device similar to the alarm system was used on Jigrad to measure the height of Jigrad children that were to become Space Pirate slaves. Those who were too short would not activate the device and would then be terminated. Samus and fellow Federation Police members interfered while it was in use, saving the lives of Damara and several other children. Later, Kreatz contemplated on selling it. Consisting of two portions, typically a pair of towers, it fires a beam that connects them.
- The sound effect of the Pirate Alarm siren was reused from Metroid Prime 2: Echoes, where it could be heard in the final report cutscene when the Dark Splinters attacked.