List of inconsistencies in the Halo series
From Halopedia, the Halo wiki
This list is compiled to show the various discrepancies spotted in the Halo universe. Inconsistencies on the list are divided into two types: internal and external. Internal inconsistencies refer to discrepancies which occur within a single source, while external inconsistencies are conflicts between two or more sources.
It is often difficult to decide which resource is "superior" to another, so conflicts are mostly listed in a chronological order. Likewise, it can rarely be conclusively determined whether a conflict is the result of an oversight on part of the author or editor(s) or an intentional retcon, unless this is specifically confirmed by the developers of the Halo franchise; such cases are noted accordingly. For more information, see here. There have been a number of cases in which an apparent inconsistency arises within an individual piece of media, only to receive a canonical workaround in another source; an example of this is the shared designation "Type-47 Scarab" for the two different Scarab models appearing in Halo 2 and Halo 3, something that was eventually clarified as "a UNSC administration quirk". For inconsistencies that have since been resolved by other Halo media, see List of rectified inconsistencies in the Halo series.
Many inconsistencies on this page are provided possible explanations, although it should be noted that these are only unofficial theories unless otherwise stated, and may not reflect the franchise developers' stance on the matters in question. If you think you can explain an inconsistency, do so here, on this article's talk page.
In instances in which two or more works have been developed concurrently and released within a short span of time of one another (e.g. games and their marketing material), the "primary" work takes precedence on this list even if released marginally later than the "secondary" one. For example, conflicting information in Halo: The Fall of Reach is said to contradict Halo: Combat Evolved, even though the novel was released slightly earlier than the game. Conflicts which are persistent throughout multiple sources are listed in the "Several sources" section.
Halo: The Fall of Reach
Halo: Combat Evolved
Halo: Combat Evolved manual
Halo: The Flood
Halo: First Strike
In Chapter 33, it is said 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
Halo: Contact Harvest
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 UNSC Midsummer Night and three frigates would be unable to repel a Covenant assault. However, they are later confirmed to be destroyers, one of which is the UNSC Do You Feel Lucky?.
In the level Dome of Light, after requesting the first Rhino to be deployed, the radio operator on the UNSC Spirit of Fire will identify the player as "Harvest Surface Command" even though the level takes place on Arcadia.
Halo 3: ODST
In the comic, Kojo Agu notes that Dutch makes a habit of never calling him by his nickname "Romeo" and instead by variants like "Romes". In Halo 3: ODST and Halo: New Blood, Dutch always refers to him as Romeo.
According to Halo: The Fall of Reach, ONI's intelligence on the Prophets as of the briefing for Operation: RED FLAG on August 27, 2552 was extremely scarce; their appearance was unknown and their existence was only inferred from Covenant communications. Debriefings and helmet recorder data from the mission depicted in The Babysitter (which can be inferred to have occurred prior to November 2551 due to the MJOLNIR Mark IV armor still being in service) would no doubt have shed more light into the appearance and role of the Prophets, which would in all likelihood have been utilized in the Spartans' RED FLAG briefing due to the mission's critical nature.
Halo: Evolutions - Essential Tales of the Halo Universe
Jacob Keyes is shown to be aware of the reason behind Dr. Halsey's mission to observe the Spartan-II candidates. However, Halo: The Fall of Reach and Halsey's journal clearly indicate that Keyes was unaware of the mission's true nature, and that Halsey had him reassigned before he could find out.
Stomping on the Heels of a Fuss
Connor Brien is stated to have spent time on High Charity prior to the events on Beta Gabriel. However, evidence suggests that the UNSC had no knowledge of High Charity at this time. Brien was deployed to Beta Gabriel shortly following the Fall of Reach in August 2552. In the Halo 2 level Regret, which takes place on November 2, 2552, Cortana refers to the space station as "something called High Charity", indicating that she is entirely unfamiliar with it or its role as the Covenant capital. Cortana's previous mission was to be Operation: RED FLAG, an ONI Section III-initiated operation to locate and capture the Covenant's leadership. It is extremely unlikely that ONI would have chosen to withhold its knowledge of High Charity from her, given the supreme importance of RED FLAG.
The Mona Lisa
It is repeatedly stated that the UNSC has a policy not to take Covenant prisoners and the main characters are baffled when they discover Covenant prisoners aboard the prison vessel Mona Lisa. However, UNSC personnel are shown taking Covenant prisoners in Halo: The Flood, Halo Wars: Genesis, and several later sources. It is likely that the "policy" to which the characters refer is a guideline or standard operating procedure rather than an official protocol.
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. Overall, Palace Hotel could be regarded as an alternate-continuity take on the story as presented in Halo 2, much as the Fall of Reach comic series is an alternate incarnation of the novel's story.
Cortana knows about the death of Colonel James Ackerson while being held captive by the Gravemind on High Charity. However, the scene takes place days prior to Ackerson's death after the Battle of Cleveland sometime between November 8 and 17.
The Impossible Life and the Possible Death of Preston J. Cole
Soma the Painter
The Auditor and the Prelate agree to inform the Didact of the Flood's appearance at Seaward. However, Halo: Cryptum reveals that the Didact was in exile on Earth at the time and would not be revived from suspended animation until nearly three centuries after the events of the short story.
Halo: Blood Line
The smart AI Iona interfaces with Victor-101 through his neural interface, even using the system to force some of his memories to resurface, indicating that he has received the Spartan neural interface upgrade allowing such connectivity. The comic series is set prior to the finale of the Fall of Reach, indicating that Victor must have received the upgrade some time earlier. According to Halo: The Fall of Reach and a Bungie Weekly Update, John-117 was the first Spartan to receive the upgrade and neurally integrate with a smart AI on August 29, 2552; this is later corroborated by the data pads of Halo: Reach, in which the Assembly makes note of the melding of John's and Cortana's neural networks as a monumental achievement in their own goals.
Halo: Fall of Reach
Halo: Fall of Reach departs from the source novel in numerous instances, with many liberties taken to better suit the comic medium. As it is not a particularly strict adaptation of the novel, one may regard it as an alternate interpretation of the original story, as opposed to an unintentionally contradictory narrative or a retcon. For a list of differences between the novel and the comic adaptation, see here.
Six Halos are described holding station over one of the Arks, which Halo: Silentium establishes as the greater Ark. However, Silentium clarifies that the newer array of six Halos was manufactured by (and hidden at) the lesser Ark. There is no apparent reason for the six rings (the Forerunners' carefully guarded last resort) being temporarily transported to the greater Ark.
Halo: The Thursday War
Halo 4: Forward Unto Dawn
Linda-058 and two other female Spartans are portrayed with long hair during the Spartans' augmentation procedures. According to Halo: The Fall of Reach, all of the Spartans had their heads shaved in preparation for the procedure.
The first issue of Halo: Initiation references Sarah Palmer as a lance corporal, and later corporal, during her ODST career immediately prior to her recruitment into the SPARTAN-IV program; this is corroborated by by Catalog. According to Palmer's biography on the now-defunct official Halo 4 website, she spent much of her Marine career as a lieutenant. Captain Del Rio calls Palmer a lieutenant when ordering her to apprehend John-117 in the Halo 4 level Reclaimer, although the context of this line has since been changed with the reworking of the rank structure of Spartan Operations; Del Rio now canonically addresses an off-screen Navy lieutenant. Halo 4: The Essential Visual Guide states that Palmer's leadership skill was the primary reason for her selection as a Spartan; if Palmer were a lance corporal, it is unlikely that such qualities could even be ascertained, as a lance corporal would have virtually no command experience. While it is possible that she was demoted prior to the events of Initiation, this is not indicated in the comic; Jun-A266 congratulates her for her promotion to corporal, and no previous demotion is mentioned at any point. Thus, it is likely that her background as a lieutenant has simply been ignored.
Halo: Mortal Dictata
Halo: Broken Circle
Halo: New Blood
Halo: Hunters in the Dark
Hunt the Truth
Halo: Last Light
Halo: The Fall of Reach - The Animated Series
Like Halo: Fall of Reach, the Animated Series departs from the source novel in numerous instances, with many liberties taken to better suit the medium. As it is not a particularly strict adaptation of the novel, one may regard it as an alternate interpretation of the original story, as opposed to an unintentionally contradictory narrative or a retcon. For a list of differences between the novel and the animated adaptation, see here.
Halo 5: Guardians
Halo: Shadow of Intent
Halo: Fractures: Extraordinary Tales from the Halo Canon
Promises to Keep
Halo Wars 2
Halo: Meridian Divide
Conflicts which involve more than two sources are listed here.
Written works vs. visual media