- In The Place of Chariots, the mission where you encounter the NTF Boadicea, Volition used the facing-waypoint SEXP to ensure that the Boadicea never appears when the player is looking directly at it. If the player turns toward the area where the Boadicea appears and never turns away, the mission will never progress.
- The mission name 'Exodus' appears in all three Volition single-player campaigns (The Main FreeSpace Campaign, Silent Threat, and FreeSpace 2).
- The mission names 'The Great Hunt' and 'Clash of the Titans' (with/without II on the end) appear in both FS1 and FS2.
- As Lightning Fall is the only FreeSpace 2 mission with no beams mounted on any ship.
- Viewed from the side, the Arcadia resembles the GTA logo.
- The Aten destroyed before the mission in La Ruota Della Fortuna is designated HLC Maltusa.
- The SCv Moloch's fighterbay was never used in the main campaign. However, it was used in a multiplayer mission.
- The TTC 1 tech container does not appear at all in either the FS1 or Silent Threat campaigns. A few of them appear in ...But Hate the Traitor, during the FS2 campaign. It also appears in the FS2 cutscene "Colossus".
- The ship name Andromeda was used for three Vasudan ships and one Terran ship: the PVFR Andromeda in The Hammer and the Anvil, the PVC Andromeda in The Pursuit, the GTSC Andromeda in On The Run, and the GVC Andromeda in a command briefing in Surrender, Belisarius!.
- The Scarab and the Ra have FreeSpace's only "in-game" depiction of a Vasudan, Shivan, or Terran. The "unmanned" Scarab has a dead Vasudan in its debris, while the Ra's story is somewhat more interesting.
- The Hermes, Centaur, Scarab, Nephythys, and Hygeia all have untargetable engine subsystems and can be disabled by a properly placed Harpoon shot. The Centaur in Enter the Dragon is ocasionally disabled by the Shakti's blob turrets, for example. The Ra has an engine subsystem as well, but for whatever reason, it cannot be disabled.
- In the second training mission of FS2, there is an installation named the Kos.
- All GTVA warships in Their Finest Hour are beam-freed by SEXP. They are beam-freed at the start of the mission, before most of them warp in, so only one Sobek is able to fire its beams.
- The Vasudans have no equivalent to the massive Argo or Asmodeus. To get around this, in Return to Babel the Vasudans actually use an Argo transport named the GTT Qeb. There is Volition concept art for the GVT Qeb class, which was apparently never made.
- The HLD Prophecy in The Great Hunt is "Neutral". Most Hammer of Light ships are set this way in missions that also feature Shivans, to allow the two to engage each other.
- The Hecate model is apparently based off of the Hades model. The bow, rear engine arrangment, and "vertical" superstructures are similar.
- Neither the Terran Mara nor the Bakha are ever "given" to the player using an allow-ship SEXP; they're only used in "scramble" missions. Nor is the Sekhmet "given" to the player; this ship is the only Terran or Vasudan fighter/bomber in FS2 that the player never has a chance to fly in the main single-player campaign. Note that you have a chance to fly the Pegasus only once, in Endgame.
- The BFGreen is only used once in the game (during Endgame and only on one of the Colossus' turrets).
- The LRBGreen was only used once, in High Noon.
- You can target your own bomb using the target-object-in-reticle key as well as the proximity target key. If you have previously acquired an aspect lock on a target, your target display will show a video from the bomb's seeker. If you have not acquired an aspect lock yet, it will show the regular display.
- The player is granted the Cyclops#short before Slaying Ravana. The player actually uses Cyclops#shorts until the The King's Gambit; he is never granted the "real" Cyclops, but uses it anyway for The King's Gambit.
- The Harbinger missile model is reused as the tip of the Stiletto missile model.
- The amount of damage that a beam can inflict on a friendly is limited. On Very Easy, Easy, Medium, Hard, and Insane, the limits are 0, 5, 10, 20, and 30 damage, respectively (per every ~.2 seconds).
- A FreeSpace Reference Bible command brief states that the Terrans or Vasudans "tried three different missile prototypes, with no luck whatsoever" against the Lucifer as it attacked "the Vasudan outpost in the Diones system".
- There are only three canon references to ground warfare in FreeSpace. If the player wins the first mission in FS2, he is told that 600,000 ground troops are sent to invade Cygnus Prime. Also, there is an FS1 multi mission where the player attacks an HoL marine convoy. Finally, the FS2 multi mission Rebel Intercept has the player intercepting NTF reinforcements headed to reinforce a ground battle in Sirius.
- FS1 command brief and tech room .anis normally had readable text. Almost all FS2 .anis, however, have some kind of nonsense text. The Colossus cutscene has several blocks of text, all of them starting with "Math is cool." The Meson Bomb command brief animation reads like an advertisement (Guaranteed to blow anything up...).
- Almost every radio message in FS2, other than training messages, is accompanied by a head animation. Several radio messages in FS1, however, don't have a head animation. None of the freighter's messages in FS1 have one, and there are two instances of "Command" not having an animation. In Eve of Destruction, if the Orff is destroyed, Command speaks without a head .ani. Also, in Paving the Way, Admiral Wolf's messages have no head .ani. In the FS2 mission Mystery of the Trinity, when the Trinity reaches critical damage, a pilot speaks without a head .ani. This is due to a bug with the personas.
- The only squadron leader or admiral that the player ever sees is Admiral Wolf. Admiral Wolf (Alpha 1's commander on the Galatea) appears once, in a cutscene (and also a few times in-mission with the normal command head .ani).
- The FS2 techroom animation for Sol shows the Earth facing "backwards" and rotating the wrong way.
- The FS1 Vasudan persona is not fully voice-acted.
- In ships.tbl in both FS1 and FS2, ship names beginning with an "@" indicate a ship that was present in the demo.
- FreeSpace contains many node inconsistencies. For example various FS1 command brief ANIs show 3 different nodes connecting Sol to other systems (but not all at once).
- Right-clicking in the mainhall allows you to cycle through interface choices.
- Mission sm3-05 in FS1 makes reference to an enigmatic "Ysusi System".
Software, mission design, and similar bugs.
- In FreeSpace 1 only, if you go into FRED and order a support ship to dock with you (through AI orders and not C-5), then you'll be thrown out of the game area at high velocity in an intense spin. Command will try to force you to warp out when you leave the game area, but you're stuck due to your spin.
- The FreeSpace engine's solution to complicated collision problems is to fling one of the offending objects far out of the game area, in the order of 500,000 units. It was once a minor pastime of the FreeSpace community to see how far one could be "flung" after messing around with the Orion's fighterbay.
- In Love the Treason..., the jump node to Regulus is named "Regulas".
- If you fire bombs into certain fighterbays, such as the Arcadia's, your bombs will fly in circles until they run out of fuel and explode.
- If you name an object "planet" in FRED, and you go near the object in-game, a message will appear saying "Too close to planet. Taking damage!"
- In the command briefing animation for The King's Gambit, the strategy is described in "Stage One" followed by "Stage 2".
- Sentry 04 in 'Place of Chariots' is assigned the cargo "Unable To Scan".
- The TC-TRI cargo containers carried by Capricorn wing in "The Romans Blunder" are friendly.
- The GTI Ganymede is never used in the main FS2 campaign, although it appears in a multiplayer dogfight.
- The SCv Moloch's figherbay "paths" are misplaced. It also has an incorrect turret normal on one of its bottom laser turrets that allows the Moloch to fire through itself. This is a common problem with Volition FreeSpace models. For example, the GTFr Chronos can fire straight through itself.
- The Myrmidon fighter is able to carry Helios anti-matter bombs, but not Cyclops or other heavy weaponry. This never has a chance to be noticed in the main campaign, as the player only uses Helios in scramble missions. This is widely believed to be either a data entry error or some kind of joke.
- During asteroid escort missions, note that the game only "hurls" asteroids at ships on your escort list. Therefore, you can make these missions easier by removing all friendly vessels from your escort list. It is not known if the same rule applies for hostile ships as well. This may not work at all in FS1, as ships marked as "escort ship" in FRED cannot be removed from your list. FSPort players face no such restriction.
- The "big damage", "huge", etc. flags are not fully implemented in FS1; it's possible to kill the Lucifer with an ML-16. They are implemented in FS2, however.
This category includes both early development decisions that were later changed, game engine changes between FS1 and FS2.
- Act I of FreeSpace 1 (consisting of the missions up to First Strike) was originally released as Descent: FreeSpace: Darkness Rising.
- Volition released a FreeSpace Alpha version to several reviewers before the release of FS1. The Alpha contained a stripped-down, incomplete version of FS1, with the two FS1 demo missions plus an original mission featuring a Fenris/Leviathan cruiser named GTC Juggernath. The mission was dropped before the official demo shipped.
- According to a table file in FS2, Silent Threat had another weapon known as the "GTM-84 Corkscrew Missle", and was "deemed too wacky for final release."
- Despite what the training missions say, support ships never run out of secondary weapons.
- The SC Cain and SC Lilith cruiser originally had a different hull design, with two fin-like appendages protruding from the lower hull. These can clearly be seen in alpha/beta screenshots.
- The Prometheus was originally introduced at much earlier time (sometime around The Big Bang).
- The mission First Strike originally had an asteroid field.
- The special-issue DVD release of Descent: FreeSpace used planet bitmaps as backgrounds like in FS2, as well as afterburner trails. These additional effects were also apparently included in the demo, although they are missing in the main release.
- If you export the Artemis/Ares/Nephtys/Ptah/Sekhmet POF to COB, you can see that the main object is called "herca", suggesting that they were either based on or were early concepts for the Hercules Mk II.
- The Bakha bomber was originally a fighter.
- Shivan ships were originally green in color.
- The SD Demon increased in hull strength 60% between FS1 and FS2, from 100,000 to 160,000 hitpoints. This may be meant to compensate for its weaker broadside relative to the Orion (otherwise the Shivans would have no decent destroyer except Sathanas).
- The Volition website  states that FS1 had a 50 point penalty for rearming (62.5 points on Insane). This feature was removed in FS2.
- In the mission Into the Maelstrom, there are 2 Elysium transports named Hauler 1 and Hauler 2. They have no purpose in the mission.
- Clash of the Titans had a Fenris class cruiser designated the Gladiator. It's arrival cue was set to false, however.
- In Their Finest Hour, the Colossus has a complicated waypoint path, implying that it was originally meant to have a complicated and dramatic battle with the Sathanas. In the final version, the waypoints are not used and the Colossus is disabled. Command orders the Colossus to warp out even though its engines aren't working.
- The FS1 voice VP contains some "alternate" voice acting for several missions. For example, the freighter and transport dialogue during First Strike was apparently first voiced by a woman.
- The command briefing for Enter the Dragon refers to "your investigation of Lucifer at Antares". Alpha 1 had not even encountered the Lucifer at that point in the campaign.
- FRED1 (the mission editor for FS1) originally had a feature known as TBL info. It is now present in FRED2_OPEN.
- The Lucifer tech description in FS1 states that it has 3 "flux" cannons. However, it only has 2. The third beam (perhaps the one used for bombarding planets) was probably meant to be mounted on the bow of the ship. (Development notes specify that a beam is to be located on each set of three red circles.)
- The high-res Lucifer model that Volition used for cutscenes has two "antennae" that are not present in the in-game model. They were probably removed for aesthetic reasons, but the non-canon HTL Lucifer re-incorporated them. Also, the high-res Lucifer has several green lights along with its red lighting which are clearly visible in the endgame cutscene. Note that Shivan ships were originally intended to be green.
- Originally the first mission in Descent: FreeSpace had the player cast as part of the Orff's crew, not the Galatea's. This can be verified through briefing screenshots taken from the alpha/beta releases.
- The FreeSpace Reference Bible seems to imply that groups ships jumping in from subspace were originally intended to all come through the same "hole", rather than each ship having an individual hole. (The pilot is soon within sight of the Terran installation. As the pilot struggles to relay his story and keep his bomber from disintegrating, many subspace holes open up in front of him, out of which streams of Shivan fighters pour.)
- There is a sound file in the FS1 VPs called "Approach.wav" that sounds like a fighter coming in to land on its carrier. This implies that Volition initially intended there to be a landing cutscene at the end of each mission, like Wing Commander. The file might also be a leftover from an earlier design choice with every mission ending with the player entering a docking bay. This was scrapped early on, due to it severely changing the way missions were played.
- The FS2 voice VP, stu_fs2.vp, contains voiceacting for an unreleased mission, M09. More information can be found on the Hard Light thread on the subject.
Most of these renamings were noticed in pre-release screenshots, model file names, or in FRED by looking at internal names used in the missions themselves.
- Hostile Vasudan wings were originally called "Steel", "Brass", "Iron", etc.
- Shivan wings were originally called "Cobra", "Viper", "Hornet", etc.
- The Cyclops bomb was originally named Belial.
- The Harpoon missile was originally named Crossbow. The name for the missile can clearly be seen in the FreeSpace 2 trailer.
- The Subach HL-7 laser was originally named Subach HL-33.
- The Subach HL-7 laser and Mekhu HL-7 laser were originally named Sidearm. The name SD-4 Sidearm can clearly be seen in the FreeSpace 2 trailer. Moreover, in the retail version of FreeSpace 2 the icon and animation files for the weapons are still called iconSD4 and SD4, respectively.
- The Akheton SDG laser was originally named DR-2 Scalpel. At some point during the development phase it was also known as Akheton DR-2.
- The Avenger laser was originally named Phalanx.
- The ML-16 laser was originally named Light Laser.
- The Harbinger was originally called the Mag-Pulse.
- The Interceptor was originally called the Shrike.
- The Prometheus was originally called the Flux.
- The Phoenix V was originally called the Angelfire.
- The Synaptic was originally called the Cluster.
- The MX-50 was originally called the Rockeye. The name is still present in the FreeSpace 1 demo.
- The Rockeye was originally called the Wasp.
- The GTW-83 Lamprey was originally called the Shrieker, and was later changed to GTW-83 Light Laser, before finally settling on the present name.
- The Hornet was originally called the Swarm.
- The GTW-66 Maxim Cannon was originally called the GTW-66 Newton Cannon.
- The Morning Star was originally called the Mace. Later in development the name was changed to Flail II. Ultimately, though, it was renamed Morning Star.
- The Hornet was originally called the Bombardier.
- NTF wings were originally called "Corsair", etc.
- Admiral Khafre's name was originally Admiral Hepsut (Surrender, Belisarius)
- The GTD Aquitaine was originally named the GTD Intrepid.
- The GTD Galatea, was originally named the ITA Repulse (FreeSpace Reference Bible).
- The SJ Sathanas was originally named Apocalypse. If you look at your event log after completing A Monster in the Mist, you can still see a goal named "Scan Apocalypse Subsystems".
- The GTFr Chronos was originally named Boar.
- The GVF Tauret was originally named Crab.
- The SF Dragon was originally named Mosquito.
- The Avenger Prototype was originally named Mass Driver Prototype.
- Shivan wings were also originally named "Scab Alpha", "Scab Beta", etc.
- For a long time the Apollo fighter was called SF-XX Generic Fighter.
- In the Alpha version, the Fury Missile still used the graphics of the left-out G-13 Medium Laser. The laser weapon disappeared completely before the original FreeSpace 1 demo, and was unique to the Alpha version. (It also looks a lot like the Tsunami colored grey.)
Allegedly, Volition contracted another company to make the FreeSpace cutscenes. They have several canon inconsistencies.
FreeSpace 1 Intro
- The "Apollo" pictured in the FS1 introduction cutscene is actually a modified version of the in-game Apollo. According to the FS1 reference bible, the Apollo in the intro cutscene is a "Terran bomber". Its gun mounts are slightly different and off-center, among other changes. Perhaps Volition placed the Apollo's gun mounts closer to the centerline for the sake of playability. The Manticore, too, has different fire points (mounted on the twin "booms" instead of centered like they are in the game).
- If you look carefully, you can see a (apparently dead) copilot in the front seat of the intro's Apollo-bomber. He is visible for less than a second. The FreeSpace Reference Bible refers to this copilot as the "gunner".
- Hercules and Medusa icons are shown on Riviera Station's radar display (although no Hercs or Medusas are visible in the cutscene).
- The captured Shivan vessel is called "Freighter", but it's actually an Azrael transport.
FreeSpace 2 Intro
- Many community members claim that the destroyer holed in the intro is the GTD Legion. However, FreeSpace 1 command briefs claim that the Bastion and Galatea are guarding Deneb, and makes no reference to any other Terran destroyers guarding the system. Volition stated that this ship was not the Galatea, and the Bastion does not bite the bullet until nearly the end of FS2.
- A Shivan Demon-class destroyer appears after the destruction of the Legion, even though the only Shivan destroyer (other than the Lucifer) in the system, the Eva, was already destroyed in Evangelist.
- The Ursa is shown even though it was not finished with R&D until after Running the Gauntlet.
- None of the Fenris cruisers had their missile launchers shown.
- A Hercules is shown crashing into the planet after getting shot down. It sits on the planet surface, relatively undamaged. In reality, an object in uncontrolled descent from orbit with the mass of a FreeSpace 2 fighter (which is hardly budged by "mutli-kiloton" missiles) would leave a deep crater in the ground. The pilot would experience extreme g-force upon impact and would not be alive to climb out of the cockpit as he apparently does in the cutscene.
- The Hades is shown as a wreck on the surface of the Deneb planet. Silent Threat command briefings indicate that the Hades was destroyed in Beta Aquilae.
- The Ganymede in the cutscene is several times bigger than normal.
- The Lucifer is smaller than normal.
- The Chronos freighters have two turrets (as opposed to the usual one), and the turrets look different.
- The Chronos freighters were either much smaller or the TTC 1 cargo much bigger.
- Mirfak is named Mirfax.
- The Galatea appears in the Colossus fleet.
This category includes mainly business decisions, but also interesting connections between FreeSpace and RL.
- FreeSpace 1 was officially distributed as "Conflict: FreeSpace - The Great War" in Europe and "Descent: FreeSpace - The Great War" in the United States.
- The GTM Infyrno is a deliberate misspelling of Inferno, for copyright reasons.
- It's FreeSpace, not Freespace (notice the capitalization of the S).
- FreeSpace 1 is called Descent: FreeSpace in the US due to copyright issues with the disk compression utility FreeSpace.
- FreeSpace 2 was originally named FreeSpace 2: Colossus (for the demo). Even before that, it was named FreeSpace 2: Exodus.
- In Greek, the plural of Knossos is Knossoi, and the plural of Sathanas is Sathanai (ancient Greek) or Sathanes (modern Greek). These are loose translations; Sathanas is simply the Greek representation of the Hebrew word for Satan. Volition always circumvented the plural by using phrases such as "Sathanas juggernauts".
Canon inconsistencies: Retail FS2 box
Several canon inconsistencies are present on the retail FS2 box (although these inconsistencies are not generally accepted as canon themselves):
- The Deimos is listed as an AWACS ship (on the backside of the box there is written "GTA Deimos"). However, the following text specifies that the ship class is "corvette".
- The Deimos has side-mounted multipart turrets that are not present in the game, or even possible under the game engine.
- The Deimos's turrets are not firing Terran Turrets. Instead they are firing Kayser like lasers.
- Only the Perseus in front of the Deimos has engine thrusters.
- On the European version of the box, the Lucifer is visible just at the right of the first Deimos's top turret.
- On the European version of the box, the Deimos is a destroyer (the nameplate on the corvette says "..D Deimos").
- The Italian version of the box says that beam weapons can be used also by fighters, according to the blurb on the back ("Imparate a usare le armi a raggi...", "Learn to use beam weapons...").