Dead Space features a number of strange occurrences, several of which provide some understanding of the underlying game mechanics. Many of them are created due to scripting; scripts that have no ability to deactivate often lead to bizarre or amusing results. See also Bugs for more standard glitches and game breakers.
Slasher Ignores Everyone but IsaacEdit
This is a very easy glitch in Chapter 1. Simply start a Cleared Game save game and go along until you enter the room where the first Slasher drops to the ceiling triggering the start of all the mayhem. Because you started a Cleared Game save, you start with your previous guns. After walking into the little hallway where the console is, shoot the vent on the far end of the hallway. A Slasher will come out. Run out of the hallway and into the room with Kendra and the rest. The Slasher will crawl through the vents and drop into the room. It stalks Isaac, but ignores everyone else in the room. It can be killed like a normal Slasher.
Probably the best known of Dead Space's glitches occurs in the hallway where Isaac is first chased by Necromorphs. After stepping into the elevator, the Necromorphs in the corridor all leap into vents above them; this is caused by a script that activates when Isaac moves past the line of the elevator door. However, the script can also activate backwards; if Isaac steps back outside, the Slashers will all drop back down again. Repeating this will lead to them jumping up and down.
During the point where the USG Kellion explodes, if you stasis the first slasher that appears and shoot off its legs quick enough, the next slasher that runs up behind it will whack it out of sight. (noticed this oddity while watching Isaac Clarke's Mind)
Dance with me, SlasherEdit
This is an odd AI behaviour that is easily seen in any room with vents around the perimeter of an uninterrupted walkway, such as this chapter's Main Lab. When the quarantine begins, if one kills all but one Slasher on the top floor, then moves around the top floor walkways, the Slasher will detect that Isaac is too far away to reach, and will enter the nearest vent. It will then jump out of the nearest vent to Isaac, by which time he will again be too far to run to, causing it to jump into the same vent. This will repeat indefinitely.
Fighting is like breathingEdit
Isaac seems to be immune to a great deal while swinging his fist. One of those things is suffocating. In Zero-G Therapy, if one carries out melee moves constantly, when Isaac runs out of air, he will not expire until he stops moving.
Cutter held like Line GunEdit
You might be able to do this odd thing in other levels, but this should be the first level you can do it. First, change your Cutter to secondary fire mode, then aim at the blind woman (You have to do this before she dies), and then let go of aim, and you're holding it like a line gun until you aim AFTER she's dead. (Note: you might have to shoot her in order for it to work.)
Dead People "move"Edit
After You start your first objective, open up the door and move the dead people around with kinesis to different places, and to make this odd thing even MORE odd, dismember them a little, then, leave, go to the store, go to the tram, and come back to the store, open the door, and you will see that they have "moved" from there place you put them to their original places even re-growing their limbs!
This happens when a room reloads back to its original state with the bodies in their original positions. This can happen in any room with pre-placed corpses.
In the same place as the previous oddiety, at the malfunctioning door, use stasis on it and put a person and an angle as if he would be split in half, then, when the door closes, his body will not be split in half, he will be through the door, then, he will disappear
Crawling dead bodies Edit
This can be noticed at the first or second chapters. Dead slashers and dismembered limbs would slowly crawl, as if pulled by a gravitational force/air vacuum until they reach a wall or a hard object. By then they will simply squeeze against it and sometimes explode for no apparent reasons.
Stomping or shooting the crawling bodies does not stop them nor their dismembered limbs from this.
Dead Slasher walkingEdit
This is a great example of two scripts failing to check each other. In the room called 'Refueling Chamber' (the one with two Kinesis switches and a large gondola), there's a ramp leading away from the first switch. At the top is a small group of Swarmers and a single Slasher. Killing the Slasher means a later sequence doesn't make sense; as the Gondola returns after the second switch is pulled, a Slasher is seen running across the hallway and up the ramp. This is the same Slasher, and may well already be dead; if it is, there will be no Slasher waiting for Isaac up the ramp, despite the one just seen going there.
This occurs because the script that spawns the Slasher at the top of the ramp doesn't check if the running Slasher script has triggered, and the running Slasher script doesn't check if the Slasher at the top of the ramp is still alive.
The Guardian creature possess an instant kill attack which is designed to prevent Isaac simply running past it, but, as it turns out, the attack itself is a proximity-triggered script that has nothing to do with either the tentacle slash animation or the Guardian itself. To prove this, run close to a Guardian and melee it constantly. For whatever reason (most likely the same glitch as not dying while meleeing in vacuum), this prevents the slash animation playing, so instead the game seemingly stores the attack trigger until Isaac is no longer meleeing the Guardian. If the creature dies before Isaac stops hitting it, Isaac's head will explode for no apparent reason as soon as he stops.
This is also why the Guardian's tentacle attack is unaffected by Stasis.
This demonstrates that the script Necromorphs use to exit air vents has no means of checking if the exit is safe. As many are aware, if the Hunter is mobile while Isaac is in the control room of the Cryogenics Lab, it will jump into a vent, attempting to drop through the one in the control room and ambush him. However, the script always picks the air vent closest to Isaac's current location, regardless of what's happening there. This means if the Cryo-chamber is active and Isaac runs towards it as the Hunter enters a vent, it will exit in the middle of the sealed Cryo-chamber and kill itself.
And there goes nothingEdit
The first time Isaac opens the door of the Cryogenics Lab, do not step inside. Instead, use Kinesis on the boxes that can be seen on the other side of the room and take them and smash them outside, in the hallway. Reopen the door to the lab, take one or two steps and turn the camera left. Next to the door, that leads in the control room, is another box. Again use Kinesis on it and smash it when it reaches you. If you can see anything else that can be picked up, use Kinesis on it and get it. Now, you should head to the other door that leads to the control room (where Dr. Mercer is in), but to do so do not pass through the Cryo Chamber (which is the obvious shorter way), rather follow the wall that has the Stasis Recharger, until you reach the door. You will now notice that you cannot enter either of the doors leading in the control room, and that the scripted speech that Dr. Mercer was supposed to give, followed by the entrance of the Hunter in the lab, never happens, leaving you stuck in here. You can try to get out of the lab, and here is the part where the glitch really shows up. If you open the door to get out of the lab, the first thing you will notice is that the hallway is really dark.Take a step outside, and Isaac falls into nothing, until he dies as if he landed somewhere. Apparently, the game has not loaded the data for the hallway properly, so the first step you take is into nothing.
Cryo Chamber Vsync GlitchEdit
This glitch only applies to the PC version of Dead Space, and it also only happens if you have a very powerful computer that can run the game in excess of 100 Frames Per Second (I was running the game constantly above 200FPS with a Core i7 and GTX 580 on Windows 7 64-bit Ultimate).
If Isaac enters the room with the Cryo Chamber when Vsync is turned off in the Visual options menu, Dr. Mercer will not appear in the control room, but his voice-over will play anyways. The Hunter also won't spawn and all of the doors in the room will be locked. Basically, the player is trapped and cannot exit the room or continue the story. To solve the glitch, quit the game, turn on Vsync from the main menu, then continue the game again. After you enter the Cryo Chamber room and you see Dr. Mercer in the control room, you can turn Vsync back off if you want to. The game was not built to run at such high frame-rates (anything above 100FPS), so sometimes playing at these rates can cause strange glitches. Vsync caps the framerate at 30FPS thereby solving any problems that might occur.
Into The Void 2 Chapters EarlyEdit
When entering Dr. Mercer's office for the first time, sometimes there will be simply nothing in the room, only complete pitch black darkness. Stepping inside will cause Isaac to fall for about 10 second before dying. After death the room should load as normal.
Isaac dies of...somethingEdit
This can be triggered sooner, such as in the Gravity Centrifuge, but one of the first places it's likely to be encountered is the zero gravity room 'Refrigeration West.' This room has numerous jumps past gratings, which can easily trigger this glitch. It seems the game's calculation of whether a jump is possible or not tends towards the 'yes' side if the result is unclear. This can result in Isaac's head grazing a surface and him becoming stuck against it, stuck in the 'jumping' pose. After a while, he dies. This is the same script that occurs when Isaac jumps into empty space and dies. There is a time limit on Isaac's jumps that says if the time limit is reached, Isaac must die. This is the reason why Isaac dies here.
It's not dead!Edit
After Isaac successfully defeats the Leviathan, then leaves the food storage chamber and returns, the Leviathan will appear to be living once more and in its dormant state. This is because it reverts from its "dead" animation to its "alive" animation once the room is exited. Despite this, it is still dead and will not attack.
This is a case of a script assuming the player will do something they don't have to. In the second floor of the Engine Room, once the burners at the back of the room are deactivated, Isaac is supposed to take the Singularity Core, which triggers a series of explosions. If he instead backtracks to the previous save point, there will be a series of explosions anyway, as the script is seemingly triggered by the burners being deactivated, not the core being removed.
Gravity Panel Marine and Legless Marine killableEdit
Just after you spot the Gravity Panel Marine moaning in pain on the ceiling, you'll come into the room with a Divider, four Exploders, and the shooting gallery. During the fight, be sure to kill at least three of the Exploders without popping their pustules. After all of the enemies are dead, grab a couple pustules with Kenesis and walk with it back to the Marine. You still can't kill him by launching a single pod at him, but getting both pustules to be caught by the gravity well, fly to the ceiling, and then shooting them will kill the marine. Sometimes, the explosion will only blow away one limb, but you can actually shoot him after this happens, which will cause parts of his body to disappear. The Legless Marine is much less complex- just walk up to him and launch the pod at him. If you're lucky, after killing each of them, you can still hear both of them groaning in pain, even though they will have likely lost their heads in the explosion.
Occasionally, Isaac will encounter a Twitcher, who will be running around in a circle very fast in an infinite loop. If Isaac approaches the Twitcher, it will stop running around and immediately jump into the nearest air vent and it will never be seen again. It is unknown exactly how this glitch is triggered.
Chapter 10 Edit
If Isaac makes his way to the cabinet containing the Crew key by an elevator, two Dividers appear on the floor below. However, if Isaac decides not to engage them, leaving the room and returning to save the game in a lobby and then reloading the game. It is very possible to trigger a second pair of Dividers to spawn. It seems as if this process is infinite, which can be both a complication and a benefit, and also must be a script error. The Dividers can be killed from the above balcony. Note, that some thrown objects (like cups, tin cans, brooms, etc.) will reappear in their original locations after leaving the room and returning.
In the rooms where the bridges must be lifted so that the Red Marker can be moved, raising one of the bridges while a Lurker is standing on it will result in the Lurker spinning around the room. This happens once the bridge falls back down as the Lurker remains in the air. Due to Lurker's unique wall-leaping ability, their AI becomes confused and spins around as if they were at the end of a rope. Even worse, they may continue to fire their barbs at Isaac while airborn. After a few seconds of this, they will break their "orbit" and land on the nearest surface and behave as normal.