Known Bugs (TFTD)
Note: Since TFTD shares its game engine with X-Com Enemy Unknown, there are many problems that are common to both games. Please track any shared/common bugs under the XCOM-EU list of Known Bugs (link at the bottom of this page). This page is just for TFTD-Specific bugs.
List of TFTD-Specific Bugs
Artifact Site Glitches
There is a rarely occurring glitch when winning Artifact Sight missions by killing all aliens. Instead of a normal end screen,the screen will turn black and then resume on one of your soldiers, but with an unmovable cursor. Reloading saves may put you on the geoscape where the game can be played normally apart from when entering Artifact Sites, where you either cannot move your cursor in the equipment screen or the ending screen from the mission when the glitch occurred is shown but the cursor can't be moved. This means you must ignore all Artifact Site missions to continue the game, but as ignoring them results in an immediate -2000 point penalty, you will eventually lose due to being shut down or running out of funds.
Research Tree bugs
See the Research Bug Avoidance Guide for full discussion. *
- Aliens can't use carried melee weapons (Vibroblades and both types of Thermic Lances), even when they are equipped with them. (This is a game engine bug is present in UFO:EU as well, but it is not relevant to UFO:EU, since in UFO:EU aliens never get equipped with any carried melee weapons.) *
- The Bio-Drone's melee attack almost always has no effect, even on unarmoured troops. (Zombie has determined the weapon has a base accuracy of 0%, presumably a programming error). This is a serious flaw in the Bio-Drone, as it always uses this attack when Aquanauts are adjacent - especially given that one of the best ways to deal with Bio-Drones is by melee combat. *
The Hallucinoid's ranged attack only works on land, but the Hallucinoid rarely/never appears on land. Presumably this is a programming error and was meant to be the other way round (only works underwater). The Hallucinoid is not given a ranged attack of any kind although the in-game description states that it has one. Its melee attack deals normal (lethal) damage although the in-game description says that it is icy, leading the player to believe that it should stun. This has been verified by several reliable sources. It does not appear on land unless the game code or data files have been modified.
- The Deep One attack looks like the Celatid spit / mortar (holdover from UFO). *
- The Bio-Drone leaves a burning trail (holdover from the Silacoid in UFO?). *
- Even though it looks like an exclusively aquatic creatures, a Xarquid sometimes appears as part of Mixed Crew missions on land, and is able to "swim" through the air.
- Despite being organic aliens, the Xarquid and Hallucinoid have the "robotic" flag set, which makes them impossible to capture alive. This is most likely because the designers used the Cyberdisk and Sectopod slots from the original game for these aliens, but forgot to remove said flags.
Mind Control Bugs
- Large units in TFTD suffer from even more bizarre behaviour than in UFO, due to an attempt to fix the old UFO bug.
- The floor maps & schematic pictures of the Survey Ship and Escort are swapped with each other in the Battlescape, the Interception window and the UFOPaedia. There is a (partial?) fix for this in XcomUtil. Zombie has provided a fix that also fixes the routes as well as the maps.
- The schematic pictures of the Battle Ship and the Fleet Supply Cruiser are also swapped in the UFOPaedia and Intercept window. The floorplan maps on the Battlescape are not affected.
- Troop transports like the Triton can be blown up quite badly in land maps (rather than being invulnerable as it should be). This somehow doesn't prevent X-COM from flying back using it.
- TFTD V1.0 There is a unit positioning bug when placing 26 men in a Leviathan. This bug is fixed by XcomUtil (and presumably in later versions of TFTD).
- 'Medic Cannon' - USO being armed with 1/0 weapons, the 'weapon' being 'medic' shown as a purple rank badge with commander's chains. with an ammunition capacity of two, but without any rounds for it. NKF says "it takes the D.U.P. Head as ammo. The launcher. Not the ammo. I don't know if the performance is the same between glitches, but I've seen this thing destroy a Dreadnaught and left no wreckage. Then at other times it does nothing."
X-COM Equipment Glitches
- Underwater-only weapons (HydroJet Cannon, Torpedo Launcher, and Disruptor Pulse Launcher, plus the Coelecanth/AquaJet & Displacer/PWT SWS weapons) are able to fire on land during XCOM's reaction-fire phase. This should not be allowed. *
- Coelacanth/Gauss Cannon ammo arming bug(s): The Coelacanth/Gauss does NOT return any remaining ammo to your stores at the end of a mission. In addition, when you assign a Coelacanth/Gauss to a troop transport, 50 Gauss Cannon rounds (used by both Craft and SWS Gauss Cannon) will be immediately deducted. These rounds cannot be refunded by any means. If you change your mind about assigning it, deassign it, and then reassign it, the premium will be deducted yet again from your stores. *
- There is a really annoying "Cannot intercept over land" message that repeatedly pops up (often more than once a second) during some pursuits along coastlines. This is probably because the pursuing aircraft is moving rapidly from land areas to sea areas and back again as it flies along a coastline. *
- When intercepting an Alien Sub that is too deep for an XCom Flying Sub's operating depth, the Sub will report "Mission too deep" and return to base, rather than tracking the Alien Sub until such time as the Alien Sub rises to a depth at which the Sub can intercept. This forces you to take control of the Sub and get it to follow the Alien Sub manually, using Geoscape waypoints. *
- Alien Subs will sometimes Touch Down on land (e.g. several hundred nm south of the North African coastline). If you respond to these missions with an Assault, they are fought at Shallow depth rather than on land. Geoscape map/terrain data bug maybe? Even worse, assaulting these subs may cause your game to crash when it tries to start the battle.
- Manufacturing Rate Limit Bug/Quirk (TFTD) - The manufacturing windows allows you to assign more technicians than the limit allowed and provides a quicker estimated time to complete the project than actually occurs. *
- Craft Gauss Cannon rearm rate. The Craft Gauss Cannon reloads at only 10 rounds per hour. This compares to 99 or 100 rounds per hour for all other cannon weapons in TFTD and EU. This is believed to be a data entry bug when changing the reload rate of the Laser Cannon (99) for the TFTD equivalent Gauss Cannon. The result is that fully reloading a single Gauss Cannon takes 5+1= 6 hours and dual Gauss Cannon 5x2+1= 11 hours. This is slower rearming than any other weapon system apart from AJAX/Stingray (which itself probably represents a design oversight on its rearming rate). *
- When generating the Geodata.dat outline map for a sunken plane mission, if the game decides to put in a small version of the right wing (PLANE19.MAP or PLANE20.MAP) it will try to place it in Geodata map block 3, 3 (tile x:30 y:30). When verifying if the block is free, the game will mistakenly check Geodata map block 1, 1 (x:10 y:10). If that block is free, it will create the small wing in map block 3, 3 regardless of what was in there. While this is a bug, its effects are quite trivial and players will not necessarily notice anything amiss were it to have taken effect.
- The more technical explanation is that instead of checking the Geodata.dat map location at 3 * 5 + 3, the game simply checks the map at location 3 + 3. The map width (5) has been omitted.
- Strange MCD records (aka the 3d shapes that form the various walls and objects in the game). Due to some strange shapes, there are some locations with various line of sight errors and clipping errors such as a bullet hitting something in mid air when it shouldn't. There are even some cases where walking into a tile is much more tiring than it should be. This is not TFTD specific, but is much more apparent.
- On ship missions, there are some metal panels on walls. These tend to remain floating in the air even if the wall is destroyed. This is only a visual bug.
- Multi-stage mission bugs
- Strange effects occur to Aquanauts who were unconscious and/or under Molecular Control at the end of the previous stage of a multi-stage mission. These effects include: the Aquanauts becoming invisible, or becoming 'wraiths' in the next mission stage. (Does this also affect XCOM-EU, e.g. the 2-stage Cydonia mission?) *
- Any Captured aliens that are carried will die when they reach phase two. The actual working logic behind this is that since the new map is generated with a new set of enemies, the 'stats' that make up the stunned alien aren't retained, but only the physical object that represents the alien is carried over. This makes capturing aliens on the first part pointless unless you intend to abort the first part after physically hauling the stunned alien back to the transport.
- TFTD V1.0 any equipment that is left on the ground on the first part of a two parter mission are not collected when you abort or complete the second part. This includes everything in the troop transport, which is lost forever. The V2.0 patch fixes this bug and returns everything on the first map.
- Dye Grenades are to all intents and purposes, useless. Arguably not a bug, but it should not have survived basic playtesting. Weak weapons (eg Dart Gun) are one thing, but Dye Grenades are pointless because they never generate enough of a screen to block visibility. The best they would do is reduce alien visual range from 20 to 17. There would be a strong case to fix the strength of the Dye 'explosion' upward from 10 to 60 (like the Smoke Grenade) or at least 30-40. *
- Stunned Aquanaut bugs. (These might not be specific to TFTD, the situations are rare enough).
- In some cases, when moving a stunned body elsewhere, and it is subsequently killed by an explosion, the corpse may appear back at its original location. *
- Stunned Aquanauts in the Triton are not reported as either inside or outside the transport sub when you abort a terror mission. *
- Stunned aquanauts that are carried by other aquanauts are listed as MIA if mission is aborted even if the carrier is aboard the Triton.
- It is possible to abort a mission even if all Aquanauts are stunned. Not sure if this should be possible?
- If the Triton is lost (aborting with no survivors), the stunned Aquanauts are shown as assigned to "Weapon-1", not their Triton, and they become inaccessible, basically lost/gone. *
- The animation for stunning a Civilian falling down shows them being violently killed.
- Zrbite spawns in locations unrelated to the Ion Accelerators. This is a result that the developers either 1) set the location of zrbite and later the ship maps were changed or 2) the developers confused the x and y coordinates in the database which specifies the specific location in the USO. In the game, Zrbite spawns when the alien items are created. Each Zrbite's OBPOS coordinates are established based on the USO position then reading the additional x, y, and z coordinates from a database, referenced to each USO.-Tycho (talk) 05:56, 3 April 2015 (EDT)
- In the CE version, clips that are loaded into weapons dropped on the battlefield will be given to the player at the time of an abort, even if the weapon in question was left on the battlefield. This is very apparent on USO recovery missions if the player immediately aborts when the battle starts and several aliens have died prior to the start of battle.*
Manufacturing Rate Limit Bug(TFTD)*
In UFO Enemy Unknown, the Manufacturing Rate Limit is just an irritant: The game prevents you from allocating more Engineers than the PRODUCT.DAT files says are needed to complete the item in one hour. This result in a minimum of one hour per item being necessary for the whole order. In an attempt to overcome this, the programmers eliminated this cap on the manufacture screen but failed to alter the code that actually determines what is produced every hour. Any extra technicians assigned over the number shown when you start an order produce nothing and their hours are wasted.
- Deep Ones are portrayed carrying a weapon, in fact it appears to be carrying an X-com issue P.W.T. Cannon craft weapon, instead of being unarmed other than its built in attack. *
- The Tasoth species is described as more resembling some sort of foot soldier in Ufopaedia. It seems highly likely that the Tasoth were supposed to be one of the grunt races, and planning issues caused there to only be 4 main races in TFTD, making Tasoth the default Psionic (MC using) race.
- The Tentaculat description states that (Zombies) cause death by touch even through armor. That's very wrong. The resulting zombies have a rather weak melee attack, especially compared to the Tentaculats. Also, the description says nothing about Zombies turning into Tentaculats upon death.
- The Ufopaedia shows the damage of a Displacer/Sonic cannon as 130, but the coded value is 110. *
- See also the Craft Bugs where the map layout, interception picture and the Ufopaedia picture are inconsistent with each other.
- The Ufopaedia describes the Dart Gun as having a ten round magazine, when in fact it has a twelve round magazine.
- The Ufopaedia shows the damage of a Coelacanth/Aqua Jet's torpedo as 90, but the coded value is 85.
- Aquanauts and SWSs are unable to move vertically in water without the use of alien technology. Apparently no one has heard of ballast belts, propellers, or flippers.
- Actually, most of the aliens are unable to move vertically in water, despite most of them being aquatic creatures!
- Thrown objects behave underwater with identical physics as on land - impossible.
- Explosions behave underwater with identical physics as on land - impossible. (See this link)
- Projectile weapons behave underwater with identical physics as on land - extremely unlikely.
- Vehicles behave the same underwater as in the air, fuel, acceleration, speed, etc. - impossible
- Alien "Molecular Control" is said to work via MC implants on the subject, but works on human Aquanauts (and civilians), regardless of whether the humans have MC implants. (They should've just called this Psionics like in Enemy Unknown.)
- X-com craft mounted Gas Cannon has an effective range of 8km. A gas reservoir capable of launching a solid bolt 8km underwater? - ridiculous.
- Underwater missions will at most take place in the light during the day and in the dark during the night. This is impossible. Sunlight won't penetrate deep in the water and most of the seabed is permanently dark.
These bugs relating to XComutil may be outdated.
- Gillmen are reported as Snakemen in some pop up messages, when using XcomUtil.
- Sometimes at the start of the 2nd level of a mission, all items, not loaded onto Aquanauts in the equip phase, appear to be lost. And some/all weapons have an ammo count of zero / no clips (possibly when the ammo was loaded automatically in the equip phase). (Believed to be related to XcomUtil teleporting 'spare' equipment back to base at the end of a level. See Talk page and Talk:XcomUtil#Open Bugs)
Items marked with an asterisk (*) have been fixed with the Extender.
Massively Profitable Alternate Craft Gauss Ammo
(Possibly should be defined as 'Light Modding' rather than an exploit, in the language of the Enemy Unknown Exploits pages.)
There is an alternate Craft Gauss Ammo type (in BASE.DAT (TFTD) at offset 0xD2). There appears to be no research path to unlock this ammo type. It looks like a late design decision was taken to have both the Coelacanth/Gauss's cannon and the Craft Gauss Cannon use the same ammo type (in BASE.DAT (TFTD) at offset D0), unlocked by Gauss Cannon research, and unusually (uniquely?) without its own ammo Research topic. This is just as well, since the 0xD2 ammo type is incredibly expensive to manufacture and uses a huge amount of storage space. The production start cost is $10,000, and each unit uses 0.6 base storage. Perhaps this was intended to be a 50-round ammo pack, like the Craft Gas Cannon (and Enemy Unknown's Cannon), in which case the cost would not have been unreasonable. Probably due to a typing / data entry error, the sell price of the 0xD2 ammo is set to $53,300, which is the sell price of Craft P.W.T. Ammo (and the Fusion Ball in Enemy Unknown). The extremely favourable spread between the build price and the sell price makes this item more than 5 times more profitable to manufacture than Gauss Cannon, far and away the most profitable item in the game. If it is true that there is no Research path to unlock this 0xD2 ammo, then unlocking it requires game file manipulation, so this is arguably a Game File exploit, and of course if one is manipulating Game Files, it's easier just to hack ridiculously large amounts of money. For those who are not inclined to edit a binary file themselves, the XcomUtil TEC:ALL option will unlock this ammo type. Possibly XcomHack could also be used. The clear profit with two full Workshops is $22.866 million per month - after all expenses including Technician salaries.