Flashlight

Flashlights are small, usually portable devices, also attachable on weapons, which project a beam of light to aid vision in darkened areas.

Flashlights are quite common in the UNSC for combat in lowly-lit environments. Some armor systems, including the ODST, MJOLNIR and SPI armors do not require flashlights due to the night vision devices and VISR systems they possess. Many UNSC weapons also have under-mounted flashlights below the barrel. In addition, most variants of MJOLNIR armor have a built-in flashlight on the helmet (in addition to night vision). Some Covenant armors have flashlights as well, such as that integrated into the armor of the Arbiter.

Gameplay
While the MJOLNIR armor canonically possesses various visual modes, including night vision, this technology is unusable in many of the games in which a flashlight is the player's only means of providing illumination in dark areas.

Halo: Combat Evolved
In Halo: Combat Evolved, the flashlight was originally intended to be only usable while carrying the MA5B Assault Rifle or M90 Shotgun, both of which have built in flashlights mounted beneath the barrel. However, this was eventually changed. The only flashlight usable in the game is that mounted on the right side of the MJOLNIR Mark V helmet, which can be used at any time. This change was incomplete at release, as the flashlight's beam will still swing with the gun's movement while melee-attacking or reloading. Marines can be seen to use the gun-mounted flashlights on the level, The Truth and Reconciliation. The MJOLNIR Mark V's flashlight has a limited battery pack which will slowly deplete while in use and recharge while turned off. The flashlight turns off when it has been activated for around a minute. Pressing the flashlight button while zooming in with a Sniper Rifle activates the rifle's night vision feature instead.

Halo 2
The MJOLNIR Mark VI armor in Halo 2 also contains a built-in flashlight. However, unlike the flashlight in Halo: Combat Evolved, it no longer has a limited battery and can be used for any length of time. However, it also has a light sensor which causes it to turn off automatically in well-lit areas, such as outdoors. Although the assault rifle is absent from the game, the Shotgun still possesses its underbarrel flashlight, although it cannot be used and no Marines are ever seen doing so.

Halo 3
The flashlight functions in much the same way in Halo 3 as it did in Halo 2. Like in Halo: CE, both the Assault Rifle and Shotgun possess inbuilt flashlights. However, the Shotgun's flashlight is now mounted on the weapon's left side rather than underneath the barrel. As before, neither are usable, and only the light built into the armor functions. Unlike Halo 2, however, the flashlight in Halo 3 does not turn itself off in well-lit conditions, and can be left on indefinitely without any negative side effects. The Arbiter, controlled by Player 2 in Co-Op mode, has a light source built into the armor over his left shoulder and it functions identically to the Master Chief's light. N'tho 'Sraom and Usze 'Taham, Player 3 and 4's characters, respectively, do not appear to possess any light-emitting feature at all, however the players can still toggle a light on and off, and this light functions identically to those used by the Master Chief and the Arbiter.

Halo: Reach
No player-armor integrated flashlight appears in Halo: Reach, instead being replaced by a usable helmet-integrated night vision device. The flashlight, however, still appears as weapon attachments on the MA37 Assault Rifle and on the M45 Tactical Shotgun.

Trivia

 * The light of the flashlight can be used to easily spot opponents using active camouflage, since the light reflects off of them. This is most noticeable in Halo: Combat Evolved, and when the contrast is turned up high, Stealth Elites can be clearly seen. The same concept works for Multiplayer.
 * In Halo: Combat Evolved, when a SPARTAN reloads his weapons or melees, the light moves with the gun rather than staying where it is, suggesting that the helmet light has no effect and is merely cosmetic.
 * In Halo: Combat Evolved, if a player acquires Active Camouflauge and have the flashlight turned on, not only does the flashlight have no visual effect, it also negates the effect of the camouflauge to enemies. So when using camouflauge always remember to turn off the flashlight.
 * The flashlight was only usable in Multiplayer in Halo: CE and its PC counterpart. In Halo 2, the same button is used for voice chat in Multiplayer and the flashlight cannot be used. In Halo 3, the controls moved to the D-pad and in Multiplayer activates chat or forge mode. Halo 3: ODST 's replacement of the Flashlight, known as VISR mode, is usable in the Firefight multiplayer game-type, being the only flashlight-derivative that can be used in multiplayer. This is the first example ever seen of a regular soldier having more advanced technology than a Spartan-II. The flashlights on the shotgun and the assault rifle remain, but they are not usable. Mickey has a helmet-mounted flashlight, but it is never seen being used. It is probably used for specific functions such as bomb defusing, although this is not shown in-game.
 * In Monitor mode in Forge, looking at a surface may reveal a built-in light, shining out of the Monitor's single eye, which may have been created to shine in front of shadows to see better. It is not present if the player sets the monitor camouflage to 'good'.

List of appearances

 * Halo: The Fall of Reach
 * Halo: Combat Evolved
 * Halo: The Flood
 * Halo: First Strike
 * i love bees
 * Halo: Ghosts of Onyx
 * Halo Graphic Novel
 * Breaking Quarantine
 * The Last Voyage of the Infinite Succor
 * Halo: Uprising
 * Halo 3
 * Halo: Contact Harvest
 * Halo Wars
 * Halo: Helljumper
 * The Life
 * Halo 3: ODST
 * Sadie's Story
 * Halo: Blood Line
 * Halo Legends
 * Origins
 * Homecoming
 * Prototype
 * The Babysitter
 * The Package


 * Halo: Evolutions - Essential Tales of the Halo Universe
 * Pariah
 * Dirt
 * Blunt Instruments
 * The Mona Lisa
 * Palace Hotel
 * Human Weakness
 * The Return
 * Remember Reach
 * Birth of a Spartan
 * Patrol
 * Deliver Hope
 * Halo: Reach
 * Halo: Fall of Reach
 * Boot Camp
 * Covenant
 * Invasion
 * Halo: Combat Evolved Anniversary
 * Terminals
 * The Commissioning
 * Halo: The Thursday War
 * Scanned
 * Halo 4: Forward Unto Dawn
 * Halo 4
 * Spartan Ops
 * Halo: Spartan Assault
 * Halo: Initiation
 * Halo: Escalation
 * Halo: Nightfall
 * Halo 2: Anniversary
 * Hunt the Truth
 * All Hail
 * The Cost
 * A Hero Falls
 * The Hunt Begins
 * Halo: Spartan Strike
 * Halo: Last Light
 * Halo: The Fall of Reach - The Animated Series
 * Halo 5: Guardians
 * Halo Mythos
 * Halo: Tales from Slipspace
 * On the Brink
 * Undefeated
 * Halo: Retribution
 * Halo Wars 2
 * Halo: Rise of Atriox
 * Halo: Legacy of Onyx
 * Halo: Point of Light
 * Halo: Infinite