The design bears resemblance to a half-sized Energy Sword, but ends in a single point rather than in dual prongs. It is mounted to a device worn on the wrists of the user.
The Energy Dagger is mainly used for assassinations by player-controlled Elites. Other uses include hostage killing, door hacking, and other unknown uses by the Covenant.
- The Energy Dagger is used in Halo: Reach exclusively by Sangheili in assassinations.
- Noble Six was almost assassinated by a Sangheili using the Energy Dagger while investigating Visegrad Relay. The Elite climbed on top of a knocked down Noble Six and proceeded to activate and plunge the Dagger downward. Noble Six was able to stop this, however, by grabbing the Elite's arm and punching it in the face. It is not shown how effective the blade is in true CQC, as Carter-A259 kicks the Sangheili off of Noble Six and Catherine-B320 sends it back with fire from her M6G.
- This is the weapon that was used to stab (and kill) Noble Six in the level Lone Wolf.
- While a Sangheili (of any class) is in Active Camo, the energy daggers can be seen activated.
- It is often mistaken as the Energy Sword in 2 cutscenes in Halo: Reach.
- It bears some resemblance in both appearance and function to the Hidden Blade from the Assassin's Creed series and the Omni Blade in the Mass Effect series.
- Looking at an Elites' shadow, you will sometimes see the Energy Dagger casting a shadow as well, as if it were activated. This is because the Energy Dagger is always present on the Elite's model, just without its texture applied. The texture applies itself during the assassinations in a wiping effect, to give the impression that its activating.
- Halo: Reach (First appearance)