The Halo universe has become a veritable lexicon of lore at this point, with more than a dozen games and countless novels, short films and other media serving to flesh out its expansive setting and mythology. From the fall of Reach to the mysterious nature of the Forerunners, Halo has managed to weave a complex and engrossing narrative that one could devote entire weeks of study to and still find more to learn.
However, as is often the case with works of fiction requiring tons of world-building over extended periods of time, things don't always add up. New bits of lore come into conflict with older bits, retcons happen, and sometimes plot holes are yielded from simple oversights as writing and development teams rush to meet deadlines. To illustrate, here are ten troublesome plot holes, puzzling inconsistencies, and outright mistakes that simply don't make sense in the Halo universe.
10 The Covenant Learning English
During the events of Halo: Combat Evolved, the various alien species of the Covenant are portrayed as having no ability to comprehend the English language, much less being able to speak it with any degree of fluency. Going forward, however, this communication barrier ends up being tossed out the window.
In terms of writing and gameplay, this makes a great deal of sense, as it saved Bungie from having to develop an entire buffet of alien languages and provide subtitles. But the in-universe explanations offered are less practical, boiling down to the Covenant just magically learning the human language on the fly as a retcon. Given the relatively tight timeline of the main Halo titles, however, it's a pretty poor excuse.
9 Cortana Really Skimps Out On The Details
When Cortana discovers that Captain Keyes is about to unwittingly unleash the flood during Halo: Combat Evolved, she hurriedly orders Master Chief to go and stop him without even attempting to explain why. Sure, time is of the essence, but if the Chief's about to fight a new and powerful adversary, a little "heads up" would go a long way.
But she offers nothing of the sort, despite apparently being perfectly well aware of the dangers that her beloved Chief is rushing headlong into. She has access the Covenant databases after all, and even if the details are few, they're enough to visibly frighten her.
8 The Master Chief's Armor Upgrade (Between Halo 3 & 4)
Halo 3 closes with the Chief taking a long and well-deserved nap after a hard day of saving the universe. When he wakes up in Halo 4, however, the Chief's wearing a shiny, updated set of Mjolnir power armor, and it never really gets addressed. Cortana simply mentions that she updated his HUD while he was snoozing, but says nothing of the hardware itself.
The common theory that gets lazily tossed at this complaint is that Cortana used nanobots to upgrade his armor while he was out, which would be a nice enough explanation if they had ever bothered to address it officially and in-game.
7 343 Guilty Spark's Combat Abilities
During Halo 3, installation monitor 343 Guilty Spark is shown to have some pretty profound offensive weaponry at his disposal despite his compact robotic form. But if that's the case, why didn't he use it against the Chief during Halo: Combat Evolved?
It is during the first game that he's attempting to stop the Chief from scuttling the Pillar of Autumn with the aim of destroying Installation 04. Given that the ring is his charge, it's assumed that he would stop at nothing to ensure its preservation. Instead, he relies on his dinky Sentinel friends to stop him with their flashlights - which doesn't really work out, obviously.
6 Cortana Is Plug N' Play
Apparently, utilizing an AI construct to plunder valuable data and intelligence from the Covenant's digital faculties is as easy as plugging in a USB drive. The idea that human technology interfaces so easily with Covenant and Forerunner technology is just a wee bit too convenient.
It could be explained that the chip she's stored on was designed for that specific purpose, but that still leaves an awful lot to be desired. Can the Covenant access human data with just as much ease, given the obvious compatibility? Are the plugs in Master Chief's helmet and Covenant computer arrays that similar? If so, how and why?
5 Sergeant Johnson Really Gets Around
During the infamously amazing Halo: Combat Evolved level entitled Assault on the Control Room, the Master Chief aids an embattled UNSC Marine element that apparently includes the well known and loved Staff Sergeant Avery Johnson. The issue presented here is that he's also supposed to be with Captain Keyes at this point in time, searching for the Covenant "weapons cache."
The simple explanation is that Bungie didn't have many UNSC Marine models to go around, and ended up reusing Johnson's to create some variety. They likely figured no one would notice, as he hadn't yet become the runaway fan-favorite character that he would blossom into. Still, the man can't be in two places at once.
4 Returning The Covenant's Bomb
Kicking off the events of Halo 2 with a bang, the Covenant decide to crash the awards ceremony being held on the UNSC's orbital Cairo station and even brought along a gift to commemorate the Chief's accolades: a bomb of immense destructive capability.
Scrambling to defuse it, the Chief manages to get there just in the nick of time. When he asks Cortana how much time was left, she responds that he "doesn't wanna know." However, given that he drags the thing through space and onto another Covenant ship, rearms it, then has way more than enough time to get clear of the explosion, there's either a plot hole here or Cortana has a tendency to exaggerate.
3 The Inconsistency Of Flood Spores
Over the course of the mainline Halo games, Flood spores can be seen in highly contaminated areas. But beyond being a cool environmental effect, these spores are actually just as dangerous, if not moreso than their fully-grown counterparts. They're capable of infecting hosts and converting them into Flood combat forms, as seen in Halo Wars. They've also got a nasty habit of clogging air filtration devices.
It's strange then that the Flood doesn't use them more actively as a safe alternative to expending its biomass, and stranger still that both the Master Chief and Arbiter are immune to them. The Chief's helmet might filter them out, but as mentioned, they clog filtration devices at a certain point. The Arbiter's open-faced helmet, however, doesn't even afford that much of a luxury.
2 How Big Was The Pillar of Autumn?
This one's a fairly straightforward inconsistency that doesn't often get mentioned. Multiple sources mention the Pillar of Autumn as being 1.7 kilometers in length. That makes for a pretty roomy spacefaring vessel, all things considered.
However, during the Master Chief's high-octane escape after triggering the Pillar of Autumn to self destruct, the player must drive the entirety of three kilometers in order to reach the Longsword fighter and thus escape the ring before it explodes. The path isn't perfectly linear, but enough of it is straightened out to raise this as an issue.
1 Why Is Master Chief The Sole Survivor Of His Escape Pod?
The first level of Halo: Combat Evolved ends with the Master Chief cramming into an escape pod with a full squad of marines, and together they escape the Pillar of Autumn to make a rough landing on Installation 04, or the titular Halo, whichever you prefer.
It's curious that he emerges as the sole survivor of the landing, however. It's doubtful that the landing killed everyone, given that seemingly every other escape pod seems to have delivered their marines relatively unharmed. If the Covenant discovered it and gunned down the passengers, then why did they leave the Chief? It's questionable, to say the very least.