List of inconsistencies in the Halo series

This list is compiled to show the various discrepancies spotted in the Halo universe. It is difficult to decide which resource is "superior" to another, so usually, the inconsistency is mentioned in the articles that it involves.

If you think you can explain an inconsistency, do so here, on this article's talk page.

There are two types of inconsistencies: Conflicts and Discrepancies. Conflicts happen when two sources disagree about a situation, subject or object. Discrepancies occur when a seemingly impossible event happens without any explanation.

Halo: Combat Evolved

 * The main view screen on the Pillar of Autumn labels the as-of-yet unidentified ring as "Halo". The name of the ring is not discovered until the level The Truth and Reconciliation.
 * Cortana says she cannot begin to calculate the pulse range of Halo just after 343 Guilty Spark finishes telling her it has a radius of exactly 25,000 light years.
 * This can be accounted for by Cortana's inherent distrust of Guilty Spark's motives. Additionally, since Cortana is an AI with an insatiable urge to know everything she can, she may have tried to calculate the range herself regardless of whatever 343 Guilty Spark had simply told her.
 * She did not state she wanted to know the range, she simply stated she cannot calculate it.
 * Almost every Pelican dropship bears the marking of Foehammer's bird, "E419", on its side, despite the fact that each Pelican has a different serial number.
 * While there is no canon explanation, this is due to the fact only two Pelican models, V933 and E419 are used the two to represent every Pelican in the game.
 * Also in The Maw, the player has to travel a direct distance of over 3 kilometers atop the Pillar of Autumn to reach the Longsword fighter, but the Autumn is only 1.17 kilometers long.
 * The Longsword's launch bay in The Maw is also at the end of the Warthog run. The front or rear of a ship is an unlikely place to store a launch bay, which implies that Master Chief traveled from side to side. This makes even less sense than the Autumn suddenly being two kilometers longer.
 * During the level Assault on the Control Room, Staff Sergeant Johnson can be seen with the Chief at the time he was really with Captain Keyes searching for the Covenant's "weapon cache"; even though the Captain has been out of reach since The Silent Cartographer.
 * This is ostensibly a result of Bungie was reusing Johnson's model instead of creating another Sergeant model.
 * In 343 Guilty Spark, when John-117 arrives at the room, he finds Pvt. Jenkins' mission recording. As he opens the door a body collapses on him. It is unclear as to why this body was not infected when the Flood overran the marines in the room.
 * This may have been done simply to add tension and suspense to the level.

Halo 2

 * In the video "Another Day at the Beach", the UNSC forces that land near Hotel Zanzibar wear ODST armor. When the Marines are encountered at the hotel during the level Outskirts, they wear standard Marine BDUs. Also, the location of the crashed Pelican does not match its position in game.
 * Also, on the Halo 2 case, the back depicts Master Chief fighting alongside ODST troops on Earth, whereas in the game, ODSTs are not present until the level "Delta Halo."
 * In the level Delta Halo, you can find dead ODSTs all around the level -- 7 to be exact. However, In Amber Clad only dropped 11 HEVs in the opening cinematic. 3 ODSTs, the Master Chief, 3 more dead, and the seven ODSTs makes 14 dead soldiers. This may just be a secret 7 reference, however, as 7=7 and 7x2=14.

Halo 3

 * Every Longsword fighter bears the marking 7-89 on its side, despite that each Longsword has a different serial number. This is likely the result of reusing the same model.
 * In the ending cutscene of the level The Storm, all of the UNSC frigates have the same serial number, and all are labeled "Forward Unto Dawn". One of the frigates is actually the Forward Unto Dawn. This is also obviously the result of reusing the same model.

Halo Wars
In the level Dome of Light, after requesting the first Rhino to be deployed, the radio operator on the will identify the player as "Harvest Surface Command" even though the level takes place on Arcadia.
 * This could be that the Spirit of Fire was still assigned to Harvest.

Halo: Reach
According to Bungie's Halo: Reach website, the M392 Designated Marksman Rifle had been replaced by the BR55 Battle Rifle in all branches of the UNSC but the Army by 2548. However, in the game, ODST Bullfrogs, who are part of the Marine Corps, are seen using the weapon in Exodus.

Halo: The Fall of Reach

 * The Eridanus II space dock is erroneously stated to be located in the Epsilon Eridani system in the chapter heading for Chapter 10. Throughout the rest of the book, Eridanus II is correctly referenced as being located in the similarly named, yet distinct, Eridanus system.


 * During Master Chief's mission to Reach Station Gamma, a Jackal's blood is said to be blue, although it is clearly purple in the games. The same mistake is made with the Elites, saying that their blood is green, while it too is purple.


 * The book describes Lt. Hikowa as male, but then later refers to the lieutenant as female.

Halo: The Flood
At one point, the book states: "Consistent with his status as a veteran, the first alien to come around the corner wore red-trimmed armor, a methane rig, and a Marine's web pistol belt. The alien wore the captured gear Pancho Villa-style and dragged it across the deck. Two of his comrades brought up the rear." That is three Grunts in the Master Chief's sight. The next paragraph says, "Confident that there were more of the vaguely simian aliens on the way, the Master Chief paused long enough to let more of them appear, then opened fire. The recoil compensators in his armor dampened the effect, but he could still feel the handgun kick against his palm. All three of the Grunts went down from head shots." It is as if the extra Grunts that appeared simply disappeared. Only three Grunts were killed, which are the three original Grunts that first appeared: the leader and the two followers. But "...the Master Chief paused long enough to let more of them appear, then opened fire... All three of the Grunts went down from head shots." It is possible, though, that the Master Chief had simply expected more Grunts to appear; he may have simply waited in case more Grunts appeared, and then opened fire when he was sure there were not any. It is also possible that Master Chief was simply waiting for more of the three Grunts to appear, giving him larger target silhouettes to hit.

''Halo: First Strike
In Chapter 33, it says that Will and Linda went out to secure the area. It then says that the Master Chief climbed up to where Fred and Linda perched. Immediately after it says that Fred and Grace disembarked the dropship implying that Fred was still in the dropship and it is presumed that it was meant to say Will and Linda.

Halo: Ghosts of Onyx

 * Dr. Halsey estimates the diameter of the Micro Dyson sphere within Onyx to be "one hundred fifty million kilometers—two astronomical units, or a radius equivalent to the distance of the Earth orbiting its sun." This is contradictory, as one astronomical unit (the distance of Earth from the Sun) is equal to 150 million kilometers, and thus the diameter of the Dyson sphere should instead be 300 million kilometers.
 * Kurt's rank was apparently lieutenant commander in 2545, as said in the prologue. However, he was still referred to as a lieutenant by 2551 later in the story.

Halo: The Cole Protocol
When Lieutenant Keyes is warned of the incoming Covenant fleet and asks what UNSC ships are nearby, the book first states that three destroyers are picketing, but immediately counters that the and three frigates wouldn't be able to repel a Covenant assault. However, they are later confirmed to be destroyers, one of which is the.

Halo: Cryptum
A Builder conversing with Bornstellar's father states that Mendicant Bias and the test-bed Halo sent to Charum Hakkor went missing after the Master Builder used a Halo to sterilize the San 'Shyuum homeworld - an event which took place only some weeks prior to the conversation. However, the implication given later on in the novel is that the Halo went missing at Charum Hakkor 43 years earlier and was not seen until Mendicant Bias used it in his assault on the capital.

Conflicts
''For the sake of convenience, most conflicts are listed under the piece of media which introduced the conflict. Conflicts which are persistent throughout multiple sources are listed in the "General" section.''

Halo: Combat Evolved manual

 * The Halo: Combat Evolved manual states that the Harvest incident took place in 2520, while all other sources specify 2525.
 * The manual also states that Captain Keyes has served in the UNSC since 2526, though he was fresh out of the UNSC OCS in 2517.
 * The Grunts are referred to as being five feet tall in the Halo: Combat Evolved manual, but in The Fall of Reach, they are referred to as being a meter tall (a little over three feet). Although it could be that Grunts are "a meter tall" in a natural combat stance, while they are actually "five feet tall" if they stand up straight, without a methane tank attached to their backs.
 * According to the manual, the Covenant attacked Reach two days before the Spartans' mission to capture a Prophet was to begin. This is contradicted in Halo: The Fall of Reach and First Strike, in both of which the Pillar of Autumn is already departing for the mission when the Covenant attack.
 * The manual describes the as being a colony ship. The ship was said to be a frigate in Halo: The Fall of Reach.

Halo: The Fall of Reach

 * In Halo: The Fall of Reach, Aki Hikowa and Ellen Dowski are female officers of the Pillar of Autumn. However, on the level The Pillar of Autumn, the bridge has no female members.
 * This may imply that, like modern navy ships, the Autumn has rotating shifts.


 * William Lovell's eyes are stated to be green in Halo: The Fall of Reach, but in Halo: Combat Evolved, the Autumn's crew has no green-eyed members.
 * This is likely a result of game engine limitations, or due to rotating shifts, Lovell was simply not present on the bridge at the time.


 * In Halo: The Fall of Reach, the description of the Pillar of Autumn is considerably different from its Halo: Combat Evolved incarnation. The bridge is described as having a command chair and a curved viewport; in Halo: Combat Evolved, this chair is absent and the window consists of several flat sections. The novel also describes the bridge as being extremely cramped, with only a meter of space between the command chair and the other stations, while in the game, the bridge is clearly more spacious. According to the novel, there is also an elevator leading directly from the engine room to the bridge. In the game, the engineering and the bridge are on the same level, and there are no doors which may belong to an elevator adjoining the bridge. In addition, the engine room is described as being "hexagonal", while in the game, it consists of two vaguely rectangular chambers with the engine core in the middle. In the Combat Evolved level The Maw, it is stated that the Pillar of Autumn has four fusion reactors, each of which is destroyed by the player; in The Fall of Reach, the ship is also said to have a single main reactor nestled within two smaller reactor rings. The ship is also described as having rotating centrifuges to generate artificial gravity; no rotating sections are present in the game, unless they are located within the hull.


 * In Halo: The Fall of Reach, when Captain Keyes awakens from cryo, Cortana informs him that the capacitors of the Pillar of Autumn's MAC gun are depolarized and the gun cannot fire, yet the gun is apparently used, and the loss of fire control is treated as a significant piece of dialogue in Halo: Combat Evolved's opening cutscene.
 * It is possible that the crew managed to get the gun working again before the battle.

Halo: The Flood

 * In Halo: The Fall of Reach, Lieutenants Hall and Dominique are introduced as members of the command crew of the Pillar of Autumn, but are absent in Halo: The Flood when the ship arrives at Installation 04. It should be noted, though, that Halo: The Fall of Reach states that there was a flutter in Dominique's heart when he came out of cryo-sleep prior to the discovery of Alpha Halo, perhaps indicating cardiac arrest. It is also possible that they were simply not present on the bridge due to rotating shifts.


 * In Halo: The Flood, the presence of the Covenant at Installation 04 is regarded as being unrelated to the arrival of the Pillar of Autumn; the Covenant are surprised by the arrival of the human ship and act as if it ended up in the system by either following one of their ships, or by chance. However, Halo: Combat Evolved, Halo 2 and the Covenant broadcast log featured in the Adjunct section in the 2010 reissue on The Flood, state that the Covenant found the ring specifically by following the Autumn's slipspace jump from Reach, and arrived at the system in advance, waiting for the Autumn on the far side of Threshold.


 * In Halo: The Flood, Captain Keyes comments that a single plasma torpedo is capable of destroying the Pillar of Autumn, though in Halo: Combat Evolved it is struck by several without losing structural integrity and breaking up. This possibly relates to the Minor Prophet's order to not fire plasma torpedoes. The Covenant ships may have chosen to fire undercharged shots to minimize damage caused by stray shots.


 * In Halo: The Flood, Cortana identifies Installation 04 as "Halo" in Halo: The Flood when escaping the Pillar of Autumn, but in Halo: Combat Evolved, it is not identified until the level Truth and Reconciliation.


 * According to Halo: The Flood, there was an ocean at the bottom of the desert plateau the Truth and Reconciliation was holding position on. However, in both Halo: Combat Evolved and Halo: Combat Evolved Anniversary, there is only solid ground below the plateau.


 * In the Halo: Combat Evolved level Halo, Cortana mentions that the survivors rescued by John-117 would be transported to the "command shuttle". The command shuttle is not mentioned Halo: The Flood, where Alpha Base serves as the main command post for UNSC forces.


 * In Halo: Combat Evolved, Cortana accesses Installation 04's Control Center by having the Master Chief remove her memory chip from his helmet and place it in the console. In Halo: The Flood, she broadcasts herself into the system using the suit's transmitter.


 * There are several differences between Halo: The Flood and the Halo: Combat Evolved level The Maw in the encounter at the final service elevator on the Pillar of Autumn. In Halo: The Flood, Zuka 'Zamamee confronts John-117 by using a Shade turret, accompanied by several Grunts. Cortana takes control of the elevator and causes it to descend, allowing John-117 to drop in a pair of grenades and take out the Covenant. In the game, there are two Special Operations Elites on the elevator and no Shade turret. In addition, Cortana does not move the elevator.


 * In Halo: The Flood, many of the Marines John-117 fought alongside were female, despite no female Marines being in Halo: Combat Evolved at all.


 * In Halo: The Flood, Sergeant Stacker is not mentioned at any point, despite him being present on several occasions in the game. He is replaced during the raid on the Truth and Reconciliation by Sergeant Parker, and for the raid on the Silent Cartographer by Gunnery Sergeant Waller. One place where he might make an appearance is when the Chief rescued a crashed Marine squad with a Sergeant and where Stacker is normally found in the game.


 * Throughout Halo: The Flood, the Master Chief's or other characters' weapon loadouts at a given situation occasionally differ from those in the game. Stocks of ammo left behind by dead marines are not mentioned either.
 * In Chapter 4, during the raid on the Truth and Reconciliation, the novel illustrates that John ran out of ammo for his MA5B Assault Rifle, switching to an M6D pistol; in the game, there are no pistols on that level at all.
 * Also in Chapter 4, it is stated that "the Spartan was carrying a full combat load of ammo, grenades, and other gear, plus two magazines for the M19 launchers". In the game, the Master Chief was not carrying a rocket launcher nor any magazines for it at the time.
 * The novel consistently describes Marines wielding rocket launchers; no marines are seen wielding rocket launchers in the game. This is obviously due to in-game constraints.


 * As revealed in later sources, the Covenant has revered Forerunner AIs as "Oracles" for a long time, but in Halo: The Flood, 343 Guilty Spark was regarded as an enemy to the Sangheili. This is likely because the fiction regarding the Covenant's beliefs had not yet been cemented by the time The Flood was written.

Halo: First Strike

 * In Halo: Combat Evolved, the Master Chief throws Private Jenkins' recorder chip away, but he still has it in First Strike. This could be explained by the Chief's suit automatically making a copy of Jenkins' recording as a possible means of gathering intelligence, although this is only a theory.


 * It is stated in Halo: First Strike that Dr. Halsey always referred to John by name, and never by rank or serial number. However, in Halo: The Fall of Reach, she called him "Master Chief" repeatedly.


 * During Chapter 33 of Halo: The Fall of Reach, many Covenant ships are destroyed, but not before they can let loose their plasma torpedoes which then destroy UNSC orbital defense platforms. However, during a space battle in Halo: First Strike, plasma en route to a target merely dissipates as the originating ship and its magnetic controls are destroyed. It is possible that the magnetic controls were not destroyed in the former instance, allowing the plasma to continue to its target.

Halo: Ghosts of Onyx

 * In Halo: First Strike, Dr. Halsey puts four M7/Caseless Submachine Guns in a bag. In Halo: Ghosts of Onyx, Kelly found the same weapons, but they were four MA5B Assault Rifles instead.


 * In Halo: Ghosts of Onyx, Kurt-051 remarks that some of the Alpha Company candidates were orphaned at Jericho VII. His speech takes place on December 12, 2531, yet Jericho VII was not glassed until February 2535.


 * On page 129 of Halo: Ghosts of Onyx, Franklin Mendez was mentioned to be "pushing sixty [years old]", which implies that his birthdate is close to or after 2493. However, this would give him a maximum age of 24 when he started training the SPARTAN-IIs, which is unlikely given his description of "grey hair at the temples" and "having seen much combat" as well as his high rank of Chief Petty Officer. In Halo: Glasslands, Mendez is also mentioned as being the same age as Dr. Halsey, who is sixty at the time.

Halo: Contact Harvest

 * Halo: The Fall of Reach states that Harvest has a population of 3 million. However, in Halo: Contact Harvest, it is stated to have a little over 300,000. The population is also listed as 3 million in Halo: Fall of Reach - Boot Camp and Halo: The Essential Visual Guide.


 * Throughout Halo: Contact Harvest, the Eridanus and Epsilon Eridani star systems are referenced as being one system, referred to as "Epsilon Eridanus". It is implied that both Reach and Eridanus II are situated in this system. With the exception of an error in one of the chapter headings in Halo: The Fall of Reach and the "Reclaimer" entry in the Bestiarum which lists Eridanus II as being located in Epsilon Eridani, the two systems are regarded as separate in most other fiction; for instance, Halo: First Strike has the main characters travel from Epsilon Eridani to Eridanus.


 * In Halo: Contact Harvest, humanity is said to have 17 planetary colonies. Throughout other fiction, the number of colonies has shown to be far greater, exceeding a total of 70 worlds. In a forum post, the author Joseph Staten suggested that a large number of the colonies are smaller settlements or outposts, though most of them are referenced as actual colony worlds in the materials they appear in. However, Staten mentioned that he was being "intentionally vague" in order to leave room for possible future expansion.

Halo: The Cole Protocol
In Halo: The Flood it says Captain Keyes killed his first human with a pistol, which was specifically stated to have a barrel; however, Halo: The Cole Protocol states he used a modified plasma rifle, a weapon which lacks any form of barrel.

Halo Wars

 * In Halo Wars: Genesis, Ellen Anders mentions the planet Onyx in passing, while giving a talk about an alien presence. However, in Halo: Ghosts of Onyx, Kurt reads a file that says Onyx has been classified since 2511. Genesis takes place in the spring of 2531. It is possible though, that like Dr. Halsey, she has a knack of looking at places where she doesn't have the clearance.


 * Although the Forerunner Relic on Harvest is discussed by Captain Cutter and Professor Anders at the end of Halo Wars: Genesis, its discovery is treated as new information in the game's opening cinematic, which supposedly takes place directly after Genesis.


 * The Spartans must be wearing Mark IV MJOLNIR armor because the story takes place in 2531, 21 years before Reach would fall to the Covenant. However, the Spartans in the game possess recharging energy shields, a feature that was added in the Mark V armor.
 * This is only a gameplay mechanic and should not be taken as canon. The developers |later confirmed that the Spartans' shield were featured merely to enhance gameplay.


 * The Magnetic Accelerator Cannon aboard the Spirit of Fire is able to deliver four rounds with a single charge, something that is unheard of in a shipborne MAC. A destroyer-class vessel can fire two rounds with one charge, as it possesses two separate MACs. The could shoot three rounds with one charge, as it possessed an advanced prototype. Super MACs around Reach and Earth could fire one round every five seconds.
 * As the rounds do very little damage to the area surrounding their targets, it may be assumed that the rounds, or the MAC itself, are not standard; the "MAC gun" in question may instead be a smaller magnetic accelerator weapon aboard the Spirit of Fire, or the rounds are fired with a lower-than-normal charge.


 * In all renders and cutscenes, most notably "She Is Not My Girlfriend" at the beginning of the level Anders' Signal, the M41 Light Anti-Aircraft Gun is shown with four barrels.
 * It is likely that this is either a variant of the M41 LAAG or a product of artistic license. This four-barreled design is also featured in the The Package, a short from Halo Legends.

Halo 3: ODST

 * The depiction of the city of New Mombasa in Halo 3: ODST differs significantly from its Halo 2 incarnation, the most prominent changes being the replacement of the Mombasa Tether to a separate island and a major restructuring of the island's general shape. As a result, the Prophet of Regret's assault carrier Solemn Penance is also moved to a different location over the city than it was in Halo 2.


 * In Halo 3: ODST, the Solemn Penance is seen as being stationary just prior to it jumping into slipspace, yet in Halo 2 during the closing cutscene of the level Metropolis, the assault carrier is moving forward.
 * During the same scene in Halo 3: ODST, the In Amber Clad is seen approaching the carrier in a straight line and is clearly separate when they jump, but in Halo 2, the In Amber Clad flies in an arc to a position underneath the starboard side of the assault carrier. These changes were made for the sake of drama and to make the scene easier to witness from the Rookie's point of view.


 * In the profiles for the members of the squad, it is shown that Kojo Agu enlisted in the UNSC when he was only 17 years old, after serving as a merchant marine. As shown in i love bees and later Halo: Glasslands, the minimum age of enlistment for the UNSC is 18 years.
 * It can be assumed that an exception was made for Agu.

Halo: Evolutions - Essential Tales of the Halo Universe

 * In the Halo: Evolutions story The Mona Lisa, it is repeatedly stated that the UNSC had a "policy" not to take Covenant prisoners and the main characters are shown to be baffled about discovering Covenant prisoners aboard the prison vessel Mona Lisa. However, there are multiple instances of the UNSC taking Covenant prisoners in Halo: The Flood and other past works.


 * The specifics of the events of the ground battle in New Mombasa differ significantly between the Halo 2 level Metropolis and the Halo: Evolutions story Palace Hotel. In addition to extensive changes in dialog, several events and locations are described differently. For example, the scene in the parking lot of the Kilindini Park Cultural Center, featured in Palace Hotel, is not present in the game. The ending of Palace Hotel is also different from Metropolis, where John makes his way to a Marine outpost in a corporate building instead of a hotel. In the game, it is mentioned that the Marines' lieutenant was killed as soon as they arrived and that Sergeant Banks is in charge at the time, while in Palace Hotel, John meets the Marines' lieutenant at the outpost.


 * In the Halo: Evolutions story Human Weakness, Cortana knows about the death of Colonel James Ackerson while being held captive by the Gravemind in High Charity. There is no way she could possibly have been aware of the event at this point, as Ackerson was killed after the Battle of Cleveland sometime between November 8 and 17, and the scene in High Charity takes place days prior (though no accurate date is given, by the way the events are presented, it can be assumed hours have passed at the most from the end of the Battle of High Charity on November 3). Even accounting for the possibility she may have somehow learned this immediately after Ackerson was executed, she refers to the event in a fashion as if she had been aware of it beforehand.


 * The Halo: Evolutions story, The Impossible Life and the Possible Death of Preston J. Cole, it is clearly stated that Preston Cole had one hundred seventeen ships under his command during the Battle of Alpha Aurigae. Halo Wars: Genesis states he only had one hundred seven in the same battle.


 * According to The Impossible Life and the Possible Death of Preston J. Cole, two of Preston Cole's grandfathers served in the Rain Forest Wars. This seems unlikely, as the conflict took place over three centuries before Cole's birth.


 * In Halo Wars: Genesis and promotional material for the game, Preston Cole is said to have been promoted to full admiral after his victory at Harvest. In The Impossible Life and the Possible Death of Preston J. Cole, no mention is made of his promotion and he is referred to as a vice admiral throughout the story, even as late as his final broadcast in the Battle of Psi Serpentis in 2543.

Halo: Reach

 * In Halo: Combat Evolved, as well as Halo: The Flood, which take place directly after Halo: Reach, the Marines on board the Pillar of Autumn are armed with MA5B assault rifles. However, in Reach, the Marines assigned to the Pillar of Autumn are armed with MA37 assault rifles.
 * From a game design perspective, this is due to Bungie declining to spend resources to create a weapon that would already have its place in the "sandbox" filled, especially given the relatively brief appearance it would make. From a canon perspective, it has since been explained that Marines will utilize Army weaponry should the situation require, as occurs in Halo: Reach.


 * According to an Intersystem News sheet that comes with the Limited and Legendary editions of the game, Jacob Keyes was already a captain in 2550. However, according to Halo: The Fall of Reach, he was not promoted to captain until after he performed the famous Keyes Loop in July 2552.


 * The placement of the multiplayer map Breakneck in New Mombasa appears to be inconsistent with the city's Halo 3: ODST incarnation. Assuming the locations of the city's landmarks, such as the bridge of the Uplift Reserve, are consistent with ODST, the map should be situated near the southernmost main section of the Reserve. No skyscrapers or streets are present in the area in ODST. In addition, according to the player's HUD compass, the city center and the Mombasa tether are situated to the south and southwest of the map, respectively. Based on the way the city is presented in ODST, the aforementioned landmarks would be located to the north and northwest of the Uplift Reserve and thus the map's playable area.

Halo: Combat Evolved Anniversary
Similar to the substituting of the MA5B with the MA37 in Halo: Reach, the M90 Close Assault Weapon System is replaced by the M45 Tactical Shotgun in Halo: Combat Evolved Anniversary. However, it performs identically to and closely resembles the M90 in the original game.

Halo: Glasslands

 * According to Halo: Glasslands, Dr. Halsey did not have an AI to help her decipher Forerunner symbols while in the shield world. However, she had the "micro" AI Jerrod in her laptop in Halo: Ghosts of Onyx, helping her translate Forerunner symbols while they traversed the interior of Onyx. No mention was made of Halsey losing Jerrod, and she still had her laptop after she and the other survivors had entered the shield world.


 * When the survivors in the shield world reestablish contact with the UNSC, Admiral Parangosky tells Dr. Halsey that it has been "five months" since John-117 and Cortana went missing after stopping the Halo Array from firing. However, John and Cortana disappeared on December 11, 2552, with the UNSC receiving confirmation of this when the Arbiter returned to Earth on December 23. The scene with Parangosky informing Halsey about their disappearance occurs in February 2553, so less than three months had passed at that point. Even considering the possibility that Parangosky may have lied, she would have no reason to do so, as both she and Halsey were aware of a transmission sent by Cortana on November 3 - less than four months earlier - in which she announced that John was on his way to Earth.


 * Captain Serin Osman claims that the UNSC had only managed to capture a Huragok once, "a couple of years ago." However, a number of Huragok were rounded up aboard the when it returned to Earth in Halo: First Strike, and one was successfully rescued from New Mombasa and interrogated in Halo 3: ODST; both of these occurred only months before the events of Glasslands.

Ancillary material

 * In Halo: Ghosts of Onyx, Frederic-104 is promoted to the rank of Lieutenant, Junior Grade near the end of the Battle of Onyx. However, the interrogation transcript featured in the Adjunct section of the 2010 edition of Halo: First Strike continuously refers to him as a lieutenant by the start of the Battle of Earth.


 * The ONI Directorate Memorandum Interrogation Findings log included in the Adjunct section of the 2010 edition of Halo: The Fall of Reach refers to Preston Cole as a fleet admiral. Though there is a conflict over Cole's rank between Halo Wars: Genesis and The Impossible Life and Death of Preston J. Cole (see here), no other source has referred to him as a fleet admiral.

General
Conflicts which involve more than two sources are listed here.


 * 33 SPARTAN-IIs successfully adapted to the augmentations. Kurt-051; Sheila, and Randall were listed as MIA before 2552, as were Jai-006, Adriana-111, and Mike-120. Samuel-034 and three other Spartans were KIA, and one WIA, but thirty SPARTAN-IIs were present to defend Reach (John-117, Linda-058, James-005, and twenty-seven of Red Team). Other KIA Spartans include Cal-141, Solomon-069, and Arthur-079. Douglas-042, Jerome-092, and Alice-130 became stranded outside UNSC-controlled space, unable to contact allied forces. Maria-062 was stationed at Earth, where she had plans of "starting a family". Naomi-010 was also apparently not present on the battle for Reach. By this count no more than 19 SPARTAN-IIs, apart from Jorge-052 of Noble Team, could have been present for the Battle of Reach.


 * The Pelican's maximum operational capacity is listed as 12 Marines in Halo: The Flood; elsewhere as 3 crew, 10 seated, 5 standing; yet still in The Fall of Reach, they can carry 30 Elites, or in Halo First Strike, 27 Spartans. It should be noted, though, that the Pelican in Halo: First Strike has all the unnecessary equipment removed -- likely including the seats -- and the Spartans are more or less jam-packed into the small craft. It is possible that there may be different variations of Pelicans, though we only see the one type in game, or that these were equipped with some kind of troop bay extension.

Inconsistencies rectified in re-releases
This is a list of disparities that remain in older novel editions, but have been retconned in later releases. For a complete list of changes in the re-releases, see here.

Halo: The Fall of Reach

 * In Halo: The Fall of Reach, the dropship used to transport the 75 SPARTAN-II children to the Military Wilderness Training Preserve was originally identified as a Pelican, whose troop bay would ostensibly be too small for 75 people. However, this was rectified in the 2010 reissue, in which the dropship is changed into a larger Albatross.


 * On page 46 of the original edition, Kelly handed out parts of a map to the seventy-five SPARTAN-II trainees. Then on page 48, when John checked to make sure the children arrived at the lake, he counted only sixty-seven...which seemed to be all of them. In the re-release, "sixty-seven" is changed to seventy-four.


 * In Chapter 22, James-005's left arm is burnt off by an assault cannon. In the original edition, it is said a few pages later that he saluted with his left hand–while it was still missing. In the 2010 re-release, he salutes with his right hand.


 * Captain Keyes refers to Ensign Lovell as "Michael" instead of "William". This has been fixed in the 2010 edition.


 * In the original, a UNSC frigate was referred to as the Alliance, and then shortly thereafter as the Allegiance. In the 2010 edition, the ship is referred to as the Allegiance in both instances.


 * In the original edition, the ship was referred to as a cruiser and then later as a carrier. In the 2010 edition, the ship is referred to as a cruiser in both cases.


 * On page 19, Michael Stanforth was said to be a Vice Admiral, and on page 95, it said he was a Rear Admiral. In the 2010 edition, he is referred to as a Vice Admiral in both instances.


 * The Pillar of Autumn was said to be missing its port-side emergency thrusters, but later used them twice. In the 2010 edition, the mention of the thrusters being missing has been removed.


 * In the original edition, the first time John-117 encounters Sangheili warriors in the battlefield is on Gamma Station during the Fall of Reach. In addition, the UNSC is depicted as not having any first-hand intelligence on the species prior to the battle; Dr. Halsey only speculates their existence. This has been largely ignored in later material, and Sangheili have been depicted as being present in battles throughout the war numerous times. References to the Sangheili as being a never-before-seen species were altered in the 2010 re-edition.

Halo: The Flood

 * The cutscene in Halo: Combat Evolved at the end of the level The Pillar of Autumn clearly shows the Autumn being fired upon with plasma. However, in Halo: The Flood, the Prophet assigned to the fleet forbids the Covenant ships to fire, lest they strike the "sacred relic". However, this is remedied in the fleet broadcast log in the ancillary content of the reissue of Halo: The Flood, where it is revealed that the order was ignored by the fleet's Supreme Commander.


 * The original edition describes how a group of entrenched Marines could not be hit by Ghosts' plasma fire, as the vehicles' plasma cannons were fixed and the marines were on a hill. In the games, the Ghost's plasma cannons can easily increase or decrease their angle. In the 2010 edition, the line is made more vague, stating the "Covenant vehicles couldn't get a fix on the Marines' position".


 * The original edition of the book consistently mistakes the 8-gauge M90 Shotgun as 12-gauge. This is corrected in the 2010 edition.


 * In the original edition, Sergeant Parker is consistently referred to as a he, and then a she. He is consistently referred to with the male pronoun in the new version.


 * In Chapter 9, the Second Squad was implied to have been completely consumed by the Flood, specifically saying that their numbers dwindled until two PFCs remained, before the last of the Marines fell. A page later, however, it is stated that there was little for Foehammer could do "except pick up the Marines, and hope for the best." In the 2010 edition, the part about picking up the Marines has been removed.


 * In Chapter 10 of the original version, it says that three weapons would be unwieldy for the Chief, not to mention "damned heavy." It then says he chose a shotgun and sniper rifle. During the ensuing engagement, it is then stated the Chief "switched to the pistol", despite the fact it was established he was only carrying a shotgun and a sniper rifle at the time. In the 2010 edition, "pistol" is changed to "shotgun".


 * In the original edition, First Lieutenant Melissa McKay's mission clock, seen in chapter headings, is prefixed by an extra 1, creating an inconsistency with the Master Chief's mission clock. This has been fixed in the 2010 edition.

Halo: First Strike

 * Similar to the inconsistency of the Spartans' first encounter with Sangheili, in Halo: First Strike, the Spartans did not have any prior knowledge of the Jiralhanae until their encounter with them on the Unyielding Hierophant during Operation: FIRST STRIKE. This has also been contradicted in multiple later works which show Brutes as being well known to UNSC forces throughout the war. Like the Sangheili encounter inconsistency in The Fall of Reach, in the re-release of First Strike, references to the Jiralhanae have been altered so that the Spartans are now familiar with them.


 * The Longsword used by the Master Chief and the other survivors from Installation 04 to land in the Ascendant Justice was repeatedly referred to as a Pelican in the original edition. The ship is consistently referenced as a Longsword in the reprint.


 * Vinh is referred to as "SPARTAN 029" twice in the original edition, even though the tag 029 is assigned to Joshua throughout the rest of the book. In the 2010 edition, Vinh is correctly referenced as "SPARTAN 030" in both instances.