Fallout 3 bugs

List all known Fallout 3 bugs here, to help other players cope with them and hopefully to help the developers fix them. ''' •READ THE LIST AND GO INTO DISCUSSION BEFORE PUTTING A COMMON GLITCH ON THE PAGE

•THE LEVEL 20 CAP WILL BE REMOVED WITH FUTURE DLC AND PATCHES'''

All platforms

 * When completing the Waters of Life quest, when you need to get to the control center, the door wont open.. you cannot exit the game, or reload from existing saved point because of auto save.. and you cannot exit the building, your game is permentaly jacked, restart a character Enjoy.
 * When killing my way into paradise falls there was a line connecting the character to one of the attacking slaves. V.A.T.S didn't work properly.
 * It is possible to get "stuck" between rocks with no way of escaping (jumping, crouching, etc.) User can fast travel to escape (if no baddies near by.)
 * It is possible to get "stuck" in "your" home at Megaton between the bed and the wall with no way of escaping (jumping, crouching, etc.) The user can NOT fast travel to escape.
 * Missing head/face in haircut screen - using the robot in the Megaton house to change appearance, you can still make the change in appearance, but you cannot preview what the change will look like because your face is missing
 * No test on desk during G.O.A.T. test.
 * Unable to proceed past the book when you are a baby. Fathers leg clip into door.
 * During the Big Trouble in Big Town quest, after bringing Red and Shorty back to Big Town, when presented with the option to defend the town by repairing the damaged robots, the game will glitch and the robots will not be in the town. A reload to an earlier save did NOT correct this issue.
 * Related to the previous bug: The robots actually flew through the air and died at my feet as I entered the town for the first time. As such, I didn't know it was a bug that would affect anything... I thought they were just enemy robots.
 * At 10th Birthday, upon being given PipBoy, unable to move, but able to look around. So you sit there looking around.  Eventually your father leaves.... and the guy goes to the bar, and you still sit there.
 * Twitching bodies: when you walk into an area with dead bodies purposely place there the bodies will load in off the ground and land in awkward position that make the body twitch
 * After aiding Paladin Hoss in finding his lost initiate, Hoss offers to escort your character out of the Falls Church area. Even though he then seems to leave you once this is achieved, every time thereafter your character sleeps in a bed, Hoss (and his companions) will appear near you --- only to immediately flee the area.
 * Just before Burke shoots Simms in the back after reporting him in, if the player fires upon Burke he will begin to point back and forth between the player and Simms with his gun, eventually shooting in a random direction until he is killed. Simms will walk to the exit of the building after this, and upon leaving will appear dead on the other side of the door.
 * When you pass between the rooms, radio may be glitched because of loading. It repeats a part of the song/speak until it turns normal.
 * It is possible when you kill something/someone, his/her/its corpse, it may be glitched. The corpse stucks and moves his/her/its body parts wildly.
 * Using the Sandman perk on some children while they're asleep leads to unlimited experience. You get the experience, but the children can't be killed so it's possible to do it repeatedly.
 * Radio songs and news skip occasionally skipping to another song or another piece of news

Technical problems

 * At 10th Birthday, upon being given PipBoy, unable to move, but able to look around. So you sit there looking around. Eventually your father leaves.... and the guy goes to the bar, and you still sit there. (This can be fixed by going to Control Panel->Sound and Audio Devices. Under Speaker Settings click Advanced. Under the Performance Tab lower the acceleration tab to "Basic acceleration" or lower and it should fix it. Enjoy!)(If that doesn't work, typing enableplayercontrols in the console forces the game to let you move around. Doesn't fix any of the sound issues though.)
 * Not responding when launching the game on XP
 * Crash when launching the game on Vista x64 - Program has stoped working message. Note that updating video drivers tends to fix this.
 * With Sound Blaster sound cards using surround sound, some sounds such as NPC speech do not always play.
 * No games saved when clicking "save". Possibly related to having a roaming user profile.
 * Severe drop in FPS at random times while playing in the wastes. Reloading a different save or minimizing/restoring the game usually fixes it.
 * Crash to desktop without a send/don't send error report.
 * Crash to desktop if Anti-Aliasing is turned on, usually when tab is pressed to bring up the Pip-Boy, but sometimes just on the loading screen. Turning AA off solves this issue for some.
 * Crash to desktop when tab is pressed to bring up the Pip-Boy
 * Crash when "getignorecrime" is entered into console.
 * Crash to desktop on exit. (Also present for some Oblivion users.)
 * Crash when "New Game" is pressed in the main menu (related to ffdshow - adding fallout3.exe to the exception list in the Audio Decoder Configuration apparently fixes this, but usually doesn't work.).
 * Crashing and corrupting top save to be back at beginning of game.
 * Crash when "Play" is pressed in the launcher splash screen (Discuss specific issues/solutions on Talk:Fallout_3_bugs).
 * APPCRASH with faulting module Cinemasteraudio.dll. Removing Roxio software, uninstalling Fallout3, then reinstalling Fallout3 appears to fix this.  First encountered issue in the bar, later saves also had issue.  The fddshow method above may be an alternative to this.
 * ~ not working to open console. Going into Device Manager Device Manager->"Human Interface Devices"->"Microsoft eHome Infrared Transceiver"->'Update Driver Software'->'Browse my computer for driver software"->'Let me pick from a list of device drivers on my computer'->'Infrared HID Device'->'Ok'->'Close' (Note: same fix works for TOEE) Once the driver has been changed, it can be changed back.  Somehow changing the driver frees the ~ mapping.  Note: Just updating the driver is not sufficient, it needs to be changed.
 * Crash on loading screen when trying to load saved game.
 * Crashes happen more frequently the longer the game is played, resulting in a "log in and crash straight back out" effect after only an hour or so of game time.
 * Crash with error "APPCRASH Fault Module Name:	d3d9.dll"
 * Disk unable to be read, viewed or otherwise seen as media on some DVD drives such as a Sony DRU-720A.
 * Memory leak related to excess processes, on-board sound card, and/or SLI.
 * VATS - severe drop in FPS for some users when entering VATS.
 * Some sound clips get stuck and loop until very far away from source. - fixed by lowering or disabling "hardware acceleration" in Control Panel > speaker > advanced [Seemingly related to EAX support]
 * Mouse lag and strange acceleration. Force vsync off in your graphics Control panel to fix.
 * Due to an error in installing, certain sound effects (like gun shots/reloading and monster sounds) do not play.
 * Drop in FPS after playing for an extended period of time. Restarting the game fixes this.
 * Rebinding The Pip-Boy key only rebinds the key to open, the closing key is still default. NOTE: As a workaround, since the three categories Stats/Items/Data of your Pip-Boy are also hardwired to the F1-F3 keys (this is unrebindable, not shown in the ingame >controls >action mapping menu and NOT mentioned in the game manual at all), you can use those instead of needing 2 different other keys for opening / closing the PB.
 * Some key bindings are dropped (very rarely) after loading a saved game.
 * Wait function does not work when button is rebound to "w" key.
 * Sometimes when firing full auto or pistols too quickly causes sounds of weapons to be silent for a few shots.
 * With 5.1 surround sound, sounds from behind come through front speakers and vice-versa.
 * Streaks, flickers, and graphical corruption on full screen with Vista and SLI enabled. Running in Windowed mode solves the problem.
 * When the Pip-Boy's color is changed, the color does not change in third person view. (In other words, if color is changed to amber, then the pip boy remains green until activated)
 * Turning on radio causes graphics to stutter, possible solution: turn down the graphics a bit, if your graphics are walking on the edge, throwing in the sound might be just too much for a few seconds, and cause the stutter.
 * On some configurations, no 16/9 or 16/10 resolutions are available in setup.
 * Cant exit vault 101 - game crash. Loading imported save dont help - game crash after walking anywhere.
 * Suddenly unable to play holotapes. Reverting to a previously saved game seems to fix it.
 * Music on the pipboy crackles and pops, while the DJs are coming in crystal clear. Is fixed by installed K-Lite codec pack, opening FFDshow and moving the directshow slider all the way to the left. *Note a properly functioning radio will have a slight underlying hiss the farther away you are from the station. This is not to be confused with the crackling/popping which is a symptom of broken codecs.
 * Defeated enemies weapons sometimes spontaneously disappear from their inventories, leaving only the ammo behind. Loading an earlier quicksave didn't help, but restarting the game and loading the very same quicksave again did fix this.
 * Pressing Tab does not exit Pip-Boy when in the Items->Misc->Keys submenu.
 * After playing for a long time, textures start to be loaded at very low resolution. Restarting the game resolves this.
 * Raiders spawn inside the stone bridge ramp between Wilhelm's Wharf and The Citadel. Raiders can shoot out from inside the solid walls.
 * Bad Z-sort of transparent hair texture when Grandma Sparkle is wearing goggles.
 * In VATS, at certain zoom levels, it won't highlight any areas on the target until you either select a new target with the left or right arrows, or unless you move the cursor to a far edge of the screen and back again.
 * If an Xbox 360 USB controller is plugged in, and if "Enable Xbox 360 Controller" is set to "Off" in the controls menu, key bindings in-game will still show as the controller. (e.g. In the HUD, instead of displaying "Use E)" which is really the keystroke you would use if the controller option was set to off, instead when your crosshair is over an item, it'll show up as "Use A)" as if it were still using the controller.) Unplugging the controller will remedy the bug.
 * In the Inventory screen, when interacting with the various boxes and containers of the game world, it's not possible to scroll the item highlight cursor up/down with the arrow keys. When you try this, all you get is an unhealthy "flicker" between items as if the cursor is stuck somehow. NOTE: This only happens when you still have the mouse pointer hovering over the list, i.e. it's not a bug at all.
 * Sometimes when user plays with an Xbox 360 Wireless controller, the game disables it and user must press on Xbox guide button in order to re-enable it.
 * In the wasteland, if user looks at the mountains, the geometry flickers even with Ultra settings.
 * When walking in the wilderness it is possible to have your feet seemingly stuck in the ground, or walking in mud, and jumping only makes a tiny jump. This followed by warping back to earlier positions and finally a crash.
 * Game is freezing for 3-5 minutes, then you can play for 3-10 minutes and it's freezing again...
 * Jumping key is very unresponsive at times, i.e. sometimes my character jumps when I press it and sometimes not. This is especially annoying when you want to jump from one building to another or across an irradiated body of water.
 * Scrolling with mousewheel in Pipboy 3000 causes fatal crash, monitor turns off and you have to reboot system
 * On the Rivet City Flight Deck, pointing towards the broken Bow is a portion that is a good deal lower than the rest. The game fails to realize this and has the player walking on thin air.
 * Cannot talk to "Mister Burke" character in the bar in Megaton (have tried disable/enable fix to no avail)
 * Small black screen on launch.
 * Wild dog totally vanishes when I brought my pipup in order to change weapon. Dog vanished when exiting the pipboy.
 * Scroll wheel problem. Using scroll wheel makes anything usable by the scroll wheel constantly up or down. e.g either fully zoomed or out on map, either fully zoomed in or out for 3rd person to 1st person, either fully scrolled up a list or down the list. If you scroll up (wheel) the scroll bar will move up to the end and will be unmoveable unless you scroll down one click with the wheel to try and put the scroll wheel in neutral, scrolling two much down will move the scroll bar down to the end. Sometimes when the scroll bug is activated after talking to someone even through it wasn't activated previously. This also affects VATS.
 * User cannot quit the game normally and has to reboot the computer.
 * Upon exiting VATS, graphics will have automatically reduced to low settings with jagged edges, flickering buildings and trees, and brightly lit pixilated shrubs. Game restart will revert graphics back to normal state.
 * Fawkes's gatling laser will occasionally cause a sound glitch when fired at a target that has just died, quicksave/quickload resolves this.

Gameplay related
To summon Moriarty you have to do this: 1)Go to his bar 2)Go into console mode (press ~ ) 3)Write and confirm: prid 00003b3c (that is Moriarty's object ID) 4)now you have selected Moriarty and can move him to any item in the world, so you can put him right next to bar stool, so write down this: moveto 00003f61 5) He should be here and act normally
 * When you are trying to escape from the vault 101, at some point you find Amata being interrogated by her father, if you choose earlier to her keep the gun, the cop will try to catch her when she stand up, and the cop and Anata move very oddly, unnatural. (maybe was just that scene? the AI took wrong decisions? Or it is "scripted" that way?)
 * When selling and buying leather armor to/from Crow (caravan driver who starts near Megaton), armor's repair level isn't uniform (i.e. I bought a set of armor at 75% repair from him and after the transaction completed, the armor was at only 25% repair). Further, selling and re-buying the same suit of leather armor will yield a fully-repaired suit! This is thus partially a bug and partially an exploit, as the player can obtain a 100% repaired suit of leather armor (DR 24!) at level 2 for less than 100 caps.
 * After speaking with Silver in Springvale, cannot find Moriarty anywhere *note* may be on balcony area outside of the bar. Pipboy may show wrong place in world map near the river. If you get this bug do these steps:
 * Speaking with Silver, even if you haven't gotten the quest to do so from Moriarty, gives only dialogue options as if the player had done so (i.e. the game assumed I'd gotten the quest already, and my dialogue options didn't reflect the fact that I'd not even met Moriarty yet, so why would I want to get caps for a drug debt from her?).
 * Sometimes NPCs get stuck on path while advancing toward deployed Frag Mines then instantly appear as though they teleported through it's triggering area. Additionally, Frag Mines have also been observed warping nearby enemies onto the Mine...which then detonate spectacularly.
 * Named NPCs spontaneously die in Megaton, possibly from falling off walkways or rad exposure near the bomb.
 * NPCs appear to float. Reloading the game fixes this.
 * Random named NPCs disappear from towns and are teleported outside of the town wall, floating in empty space. Some quests are unable to be finished in normal gameplay due to this bug. Temporarily solution is using the "tcl" command in the Console to reach those NPCs. Also you can use these commands in console mode to bring NPCs back: prid (disappeared NPC objectID), moveto (AnyObjectID). Object IDs can be find out in console mode (~) by clicking on character/object.
 * AI and scripting bugs related to the "Dogmeat" companion, where the dog will randomly attack friendly NPCs.
 * Scribe Rothchild can get stuck, making the main quest line impossible to continue. Can't be fixed by traveling elsewhere, pushing the character, or making him unconscious. This bug is possibly caused by Rothchild leaning to a wall in his room when you speak to him about the vault. This is fixable by entering console (~), clicking Rothchild, typing "disable" and after that "enable" (worked for me at least). Another possibility that works: If you have a savegame before talking to Rothchild and he is already stuck beside his bed: you can WAIT until night - then Rothchild is suddenly sleeping in his bed and then you can talk to him about the vault.
 * Game load state may not exactly match game save state: a fresh set of enemies were spawned next to the player at the graveyard north of Big Town when loading a quicksave that was created after the player had just killed all the enemies in that area.
 * Game freezes while traveling up the elevator to the top of the Washington Monument.
 * Those! quest can break if player visits Marigold station and clears it of ants before prompting. When prompted to return, scientist will not be present, queen ant unreachable. This may also be a result of approaching Greyditch from the wrong direction, skipping initial trigger.
 * Jefferson Memorial Crash - While traveling or approaching the Jefferson memorial during main quest the game crashes. (This only occurred after speaking to Dr. Li; walked past Jefferson Memorial without trouble on the way into Rivet City.}
 * Liberty Prime gets stuck and does not progress forward, making it impossible to finish the quest. (Can be fixed by waiting for an extended amount of time with the WAIT function. If this fails, Liberty Prime can be nudged by using the noclip cheat until he no longer glitches. To enable or disable noclip, press the tilde '~' key and enter the command "tcl".)
 * Blood Ties quest is unable to be completed. When knocking on the doors of one of the two locked houses, you get stuck on the "..." message and have to reload a saved game. Possibly caused by entering the West's house before knocking on the 2 doors.
 * The Declaration of Independence's optional quest is to retrieve Ink from Arlington Library; however, after the optional quest is completed, the Ink is still occupying your space in your MISC inventory and cannot be removed.
 * If you revisit Vault 87 following completion of the main quest mission (accessing it via the Reactor Chamber), then open the vault door from the inside, there is no rendered exterior and you are confronted with a void.
 * After blowing up Megaton, attempting to reenter Tenpenny Tower results in a crash with exception 0xC0000005; a memory access violation.*
 * Upon saving Lucy's brother from the family and returning to Arefu, any attempt to enter the houses results in the game freezing and possibly wiping all save games. NOTE: I completed said quest and nothing happened to me, so probably it's not a general issue that all users experience.
 * After meeting with Ian West in Arefu when i had just saved him, all the other people of Arefu turned hostile towards me. The crazy wife was lieing dead on the street and I don't think i had killed her. Before that happened, i saw a barrel falling out of the sky. (Confirmed. Not the only user to have the inhabitants of Arefu go ballistic after a random barrel strikes down one of the citizens: http://www.bethsoft.com/bgsforums/index.php?showtopic=898197)
 * In the Republic of Dave, when Dave asks you to tell everyone to vote in the election, after I told Bob to go vote, I went to the wait screen and waited for about 5 hrs to get the sun up, after that I entered the building and he is refusing to move or vote, he stands in front of the box staring at it, but interaction with him is still possible.
 * The two paladins (Hoss and helper) are hostile towards the player when entering the area for the first time and cannot be interacted with.
 * When leaving Rivet City Marketplace after closing time, the "Dogmeat" companion is suddenly missing. This occurred several times after reloading a quicksave inside the market. Fourth try finally worked, so it's possibly avoided by leaving the market earlier on time.
 * When doing the replicated man, if you take the android component but reveal the truth to Harkness, it will remain in your inventory, but you will not be able to talk to Dr.Zimmer to remove it.
 * All Brotherhood of steel members starts as friendly and then turn hostile towards the player after first contact for no apparent reason.
 * There is a large City Liner coach on the south-west side of Vault-Tek Headquarters that can be bashed around by simply walking into it.
 * After killing the guardian ants but not killing the queen ant in "Those" quest, after talking to Doctor, he walks to the Queen Ant and then escapes.
 * It is possible to lock yourself in Vault 92 when attempting to complete quest 'Agatha's Song'. If the player presses the same button he/she used to open the door, then enters the vault, the door will close behind them. Could not find any controls to open the door from the inside.
 * In the quest 'Head of State', Hannibal takes forever to get to the Lincoln Memorial. I followed him and he was going the wrong way constantly, going to everywhere he could get killed, swimming through the Potomac River and getting stuck there. And why is he walking there? Why can't he run?
 * After bringing Cherry to Rivet City to free her from Dukov, she stayed on the bridge outside of the city. In a subsequent fast travel to Rivet City, she respawned in the same spot, except the bridge was no longer extended so she immediately fell to her death.  It's not a game-breaking bug.  It's just sad.

Common User Errors

 * Player stuck unable to move, HUD also missing. Possibly due to bumping the "~",which opens the console to input cheats, directly above the TAB. If the cheat console is not open, pressing the tilde (~) key and typing "enableplayercontrols" will fix this.
 * Sometimes you get stuck in "slow walking mode" CAPS LOCK, which locks down "run", is probably enabled (and possibly toggled when you Alt-Tab out of the program if the light is mismatched), toggled it off by hiting the key again. Player might also be encumbered, carrying too much

PlayStation 3

 * Slow or Jerky Movement while in The Vault. (akin to Lag in an Online game), might be fixed by rebooting your PS3
 * Graphic Glitch - Officer at Birthday Scene has left eye that stretches out for the entire viewable screen and follows head / eye movement
 * Game freezes during GOAT exam, may be circumvented by saving and reloading.
 * Susie Mack's Test results some times skips completely and she walks out of the room
 * At the birthday scene, the door in the back opens up after some dialogue, and if you go through, you will be warped to another part of the vault, with no way back to the birthday scene
 * Jefferson Memorial Freeze - While traveling or approaching the Jefferson memorial during main quest the PS3 freezes.
 * Random objects blocking models both PC and NPC. If outside fast-travel, if unable to fast-travel load last save.
 * Dogmeat rocks quickly forward and backward as though his physics are off when standing idle. This seems to be triggered when loading a save where Dogmeat is set to the "Stay" command.  Fast traveling and reboot do not fix it.  Only loading an earlier save will correct the problem.
 * After visiting the GNR building, the player may find themselves permanently locked in/out of the building.
 * Speech Errors - NPC's mouth moves during dialogue but nothing is said. Script/subtitles at the bottom of the screen "fast forward".
 * When playing with notification messages turned on the game may freeze, the game will return to normal after the notification has gone, go to system settings and turn off notification messages to solve the problem.
 * Megaton NPCs dead for no reason - Possible death from falling from a height. I can at least confirm that Walter can die this way.
 * PipBoy moves up a little in the screen each time you view it. Repeatedly viewing and hiding PipBoy will eventually render the whole PipBoy screen invisible. Keep opening and closing eventually will reset to normal.
 * Loading screen progresses half way then freezes.
 * Sometimes while saving (or autosaving) while in motion or firing your weapon, when you return or reload the save you will be unable to fire your weapon or reload it. Your gun will begin to fire randomly and it persists no matter what weapon you use and the same happens when unarmed or with a close-up weapon. V.A.T.S. becomes inoperable, it will enter slow mode but your weapon will never fire. The only way to fix this is to reload a previous save or to prevent it from happening by never saving while in motion or firing/fighting/jumping etc.
 * Irreparable hardware corruption. A small minority of people have reported issues with the game crashing after which they were unable to restart their PS3 or if it would start it would be unable to play any games or blu-rays for periods of time greater than 30 minutes to one hour. !Freezing does not damage your PS3, but complete crashes have the possibility to! Note: This hardware error has happened before this game was released. Mainly occurred on launch PS3s and repair cost around 140 dollars
 * Graphics Glitch - While in third person mode if you back up into a wall (forcing the camera to zoom in and your character to become invisible)it will glitch if you walk out of it slowly and your body will become invisible (except for your head and your weapon). Reversible by switching in and out of third person and first person mode.
 * If the game is started with the controller set to Controller 2, 3, or 4, the game will still be playable, but L2 and R2 will fail to function. This makes it impossible to enter V.A.T.S. or switch views.  Restarting the game after reconfiguring the controller will fix this problem. Also, holding the PS button, turning off the controller, and turning it back on seems to help.
 * NPC will fall through the floor/ground
 * V.A.T.S. will freeze before showing percentages

Xbox 360

 * When quick traveling to Raven Rock with Fawkes, Fawkes will spawn and not respond/follow you, or, he will spawn partially in the ground where you are standing. Quick traveling to a new area will fix the issue.
 * During early game, near Bethesda Ruins, a horizontal line with a vertical triangle on top towards random enemy shortly before combat, lasted until death. Reverting to save did not fix, but system restart did. May be an isolated glitch.
 * After fixing the water leaks in Megaton, Walter disappeared completely, thus making the mission impossible to finish. Have not found fix yet. NOTE: He can randomly fall to his death sometimes. Look behind brass lantern or the doc's and you'll find Walter's dead body to verify.
 * Cannot read disk during tuning of the "Radio" or any other random event, usually at the beginning of gameplay. The longer you play, the less likely this happens. Restart system fixes.
 * Sometimes while approaching the Jefferson Memorial the game freezes. Clearing cache does not work to fix the issue.
 * Some people have main quest achievement problems.
 * After dying and having the game auto-load, sometimes the primary fire button will get 'stuck.' By this, you cannot fire by pressing the trigger. It will keep firing automatically every few seconds. So far, the only known way to fix this is to completely shut down the console and restart it.
 * After getting into a fight in Tenpenny tower and speed traveling away the game locks upon re-entering Tenpenny tower. The only fix is to re-start from an earlier save.
 * After completing The Wasteland Survival Guide Mission where you hide an observation device in a Mirelurk Lair, Fast traveling back to Megaton causes an infinite load time. It goes to the load screen but never succeeds in loading Megaton. Restarting the Xbox has not helped.
 * When heading toward Three-Dog for the second time, after installing the dish, Pip-Boy screen got progressively brighter until it was no longer readable. A save, and restart of the game through the Dashboard was able to fix the problem. This has also occurred in other situations, and may be triggered by long periods of play.
 * After seeing the Enclave for the first time in the Monument, Dad fills the control room full of radiation. As you try to escape with Doctor Li, load freezes trying to access the next room. Restarting and switching to a friends X-Box has not helped the problem, as well as switching to another disc.
 * After assisting the temple of the union with the Lincoln memorial the refugees never show up if slavers are killed first. The only known solution is to wait until Hannibal asks for help with slavers before eliminating opposition at the memorial. WORK AROUND: Sometimes Fast Traveling around to random locations/ waiting for a few days to pass, after coming to where the arrow shows, they will be there. they're just slow.
 * Upon doing Trouble at home quest, player can only move with the LS, the RS non-functioning yet it works in pip-boy, previous saves, reloads, all have no effect, have to restart unless someone finds a fix, 16 hrs in!
 * All notes have vanished from the Note page under the Data tab for unknown reason. WORKAROUND: Saving the game and using the xxlbrbxx cashe clear code on the dash board solved this problem.
 * Randomly, upon exiting Megaton, a clipping issue occurs where the players legs sink into the "soft" terrain (not affected when on cement or rock). This causes movement to become sluggish/jerky and makes corpses sink and become unsearchable. Loading a previous save seems to fix the problem.
 * Megaton NPCs dead for no reason. Possibly caused by falling from higher ground.
 * After getting the G.E.C.K from vault 87 yourself instead of letting the friendly super mutant do it you will get caught. But after you have been caught and go back to vault 87 and open the vault door to wasteland there's a huge glitch there cause when you try to walk to the wasteland you fall threw the floor. I did this several times to check. The pathway to wasteland is also not visible but a big grey square. A huge bug!
 * When setting Dogmeat to the "Stay" Command, it is possible that upon returning to that location, he may be gone. You will not get the prompt that says he is dead, and so far it is unknown where he has gone. (a message should pop up after letting dogmeat wait for an extended period of time that says dogmeat is waiting for you outside of Vault 101. this is not a glitch)
 * (END GAME SPOILER) The game randomly freezes when you're following the big robot at the end of the game.
 * Upon arriving in Big Town, speak to a girl named Bittercup, where she will rant about how she has been with all of men in Big Town. In this rant you find out specifically about what happened with her and Pappy. End the conversation with her and talk to Pappy. A couple lines in you'll have a speech option that will never go away and can continue to gain experience as long as the speech is successful (It was 100% when my speech skill was at 30).
 * Game randomly freezes every 10 seconds to 2 minutes. (Cache clearing and HD formatting had no effect).
 * try speaking to a traveling merchant while he is swimming with his head above water so the conversation is allowed. When he's introducing himself his head will make a full 360 turn counter-clockwise.
 * The runaway slaves randomly aggressed only companion and not the player. The only way to escape this is to run away from the compound and fast travel, hoping they haven't killed him by then.
 * While walking around Vault 106 everything turned purple, after a few seconds it would go back to normal and have a flicker affect, this happened about 5 times in a 3 minute period. Leaving the vault was the only thing that fixed it. (NOTE: This is not actually a bug at all, but part of the game, Vault 106 is constantly cycling drugs through the vents.)
 * IN REGARDS TO "TAKE IT BACK MISSION"When you're in the Citadel science lab and the Lyon's Pride is talking to the "head guy" (forgot his name, the one wearing a robe), they will be in conversation with each other, when you approach them make sure you are visible to the elder guy in the robe (meaning you can see his face), the game locks you in for the in-game cut scene and you cant move, if you cant see the elder's face, he won't be able to communicate with you and you will end up just standing there until you reload the save.
 * THOSE! mission in Marigold Station. There's a fire ant at the bottom of some stairs sitting on the track of a door(half-in, half-out). When approached too close and killed the body sticks to the player. It's headless body dangles and jiggles in front character and can only be gotten rid of by reloading.
 * The giant robot "Liberty Prime" can get stuck on the left side of the highway when heading to install the G.E.C.K. Going forward and fighting some enclave soldiers can fix this problem. (Save immediately when you see liberty prime walking for the first time to avoid this bug.)
 * After fighting and killing a Super Mutant outside Chevy Chase station, upon reentering the station the game froze. When the game was reloaded from auto save after a system restart, the Super Mutant was alive again, but immortal. Repeated bursts to the head did no damage.  Was still vulnerable to splash damage from frags. (after playing Fallout 3 for over 100 hours now this is one of the two glitches i have encountered. I've run into ten or so invincible enemies. VATS wont hit them and neither will free aim. Simply leaving the area solved the issue and the glitched enemies were always outside so it didn't make questing difficult, and like I said its a rare occurrence anyway)
 * When approaching the Super Duper Mart at dawn, all the raiders spawned outside the building at once, creating an unbeatable mob of raiders which spawned right in front of the player. Reloading and waiting a little while allowed them to presumably walk inside.
 * If the player fast travels to the Citadel when escorting Dr. Lee to the location during the "Waters of Life" mission, Dr. Lee will move to the right of the entrance and refuse to move. Attempting to force her to the door is ineffective, as she constantly walks back to the wall and paces back and forth. This glitch in the main storyline is considered to be game-ending.
 * Bridge to Anchorage War memorial covered in land mines has a glitch. One of the mines is active but is not visible by the player. Trail and error to collect mine.
 * Occasionally when climbing the steps to the plaza above Anchorage war memorial the game will crash, This can be rectified by resetting the console.
 * Extremely rare freezing (1 time in 20 hours of gameplay) where the console would freeze for no reason - Save often just in case
 * Crouching and un-crouching while using the mini gun will cause it to stop firing even though it still uses ammo and makes the spinning animation.
 * In one save, after installing the dish at the Washington Monument, I went back to talk to Three Dog only to find myself locked out of the GNR Building. Using the intercom does not help, as Three Dog just tells you that the door is open. Worked my way around this by getting a higher lock pick skill, and picking the door lock on the second floor. The main door remained locked for the entirety of the game. Bug has been reported to happen in several different locations other than the GNR Building.
 * The quest Shoot Em' In the Head is glitchy. After telling Tenpenny that I would kill Crowley for 300 caps and then doing it I can not receive the quest reward or the achievement. I had to reload a save file and give the keys to Crowley to get the achievement. I then had to reload my main game and just accept that I couldn't complete the quest on it. I tried giving Crowley the keys and then killing them and taking them back but that just completed the quest by giving him the keys, not the Tenpenny optional quest of killing Crowley.
 * After completing the "Tenpenny Tower" quest (by negotiating with the residents of the Tower to let the ghouls in), Tenpenny disappears completely and is considered 'dead' for some reason. (Inquiring around with the quest Ghoul NPCs provides hints that he was murdered by them. This is not a glitch.)
 * When player leaves Vault 87 before collecting GECK but after Fawkes is in position to get it --but not told to, yet-- one of the doors on the way to the GECK chamber will be locked when player reenters. It is the door in the room the Enclave will ambush the player in on her way out with the GECK. The lock cannot be picked. I'm not aware of a workaround, currently.
 * "HEAD OF SLATE Side quest" In Downtown D.C. Hamlin appears to get stuck. A Tesla-Photon barrier has been set up but only the generator is visible.
 * In the "Wasteland Survival Guide" quest, in chapter 3, after doing the Rivet city section, returning to Moira, and picking all options other than the lie, then choosing the "Take a break from the research." option, the quest becomes impossible to complete. If you speak to her again, she repeats all of those same options and then only gives you the choice to take a break from the research. The only solution is to lie, which alters the outcome of the quest and gives you bad karma.