The Guardians are a variety of sessile Necromorphs. They are anchored onto walls, their flesh fused together with The Corruption. As a result, they cannot actively hunt for prey, but serves as, true to their name, guardians to areas important to the infestation, or simply as hindrances that Isaac must clear in order to proceed.
While they are immobile and do not have any visible repurposed limbs, they are capable of killing anything that draws near instantly, striking the victim with a lethal scythe-tipped appendage, made from the host's intestines.
Guardians are created from a single human body that has been fused together with the Corruption growing on the walls, thus establishing a form of symbiosis. The transformation of the host is quite extensive and both their first and last stages can be witnessed.
At the beginning, the host, or at this stage the premature Guardian, still retains their human characteristics; however, they're heavily mutilated. More specifically, the torso is only intact down to the waist, where the abdomen is vertically split apart with the entrails hanging out.
At this stage, the newly formed Guardian is extremely weak and lethargic, easily dispatched and is incapable of performing any kind of lethal attacks. At the very most, they will play dead until approached, or otherwise alerted, when the Corruption will attempt to cause damage by flailing out the host's intestines over which the host has no control.
Despite the severity of the body's condition, it is clear that the host is still clinging onto life, still wailing in pain and agony. This fact further establishes the notion of a symbiotic relationship with the Corruption, as it would be not otherwise possible for a Human being to live for so long having sustained such extensive damage.
Given sufficient time, the torso will transform and ultimately develop to the stage of a mature Guardian. The fusion between the human body and the Corruption has been, for the most part, completed, with the two being indistinguishable from each other, with most of the human features of the host body being unrecognizable at this stage.
While the Guardians do continue to scream and moan, suggesting that at least some part of the human brain is still functioning even at this stage, their transformation is otherwise very drastic.
The first thing one notices is the apparent increase in size compared to the previous stage, a result of the fusion with the Corruption's biomass. Moreover, the human arms, that were a characteristic trait of the premature stage, have now disappeared, probably atrophied or otherwise consumed by the Corruption, as they currently serve no purpose. Alterations can also be seen on the head of the host, with the lower jaw and part of the neck completely missing, exposing the trachea and leading to a wide open thorax and a newly created sac where the abdomen used to be. The latter two are two body structures that have been re-purposed and created, respectively, in order to accommodate with the Guardian's functions.
The thoracic cavity now serves as a place for the newly created tentacle appendages to rest. The creature has two kinds of said appendages. The first kind, are the appendages that are used to further anchor the creature on their spot and are instantly drawn out once the Guardian has spotted a hostile in their vicinity. The second kind of these appendages however is a single scythe tipped tentacle that serves as the creature's only means of attack in close quarters and is what makes the Guardian extremely lethal.
The sac is in fact an orifice that serves as a canal for the Corruption to spew out embryonic spawn, known as Pods, which will aid in attacking and keeping detected threats at a distance.
- In order to kill a Guardian, all of the tentacles that sprout from the chest cavity need to be severed. If there is access to any kind of explosives, be it an explosive canister, or a weapon's firing mode, aim and shoot them at the opening on the Guardian's chest, when all of their tentacles are drawn out, for an easy kill.
- Premature Guardians, for the most part, are not considered dangerous and ammo should not be wasted on them. However, if one was so choosing to end the once-human host's suffering, a single shot to the head/neck of the body will kill them instantly.
- As a side note, while some premature Guardians are truly harmless, certain others (even when they are dead) can harm or even kill Isaac while flailing their intestines, although the damage dealt is almost nothing.
- Do not open fire on a Guardian until they have released their tentacles onto the wall they are anchored to. If you shoot them before they notice you, you won't do any damage.
- Always keep a distance from the Guardian at all costs. Attempting to get close to use close ranged weapons, such as the Ripper, is usually fatal, as the Guardian launches a bladed tentacle from their torso which can decapitate Isaac instantly.
- Guardians spit out Pods which will open fire on the player with a ranged attack. The Pods will also detonate when they are killed and/or if one comes too close to them, though the detonate on death does nothing. They can be easily dispatched by severing their tentacle with the weapon of your choice.
- The mines fired by the Line Gun can make short work of a guardian as the lasers will dismember most of the anchoring appendages, given that they are out of the cavity.
- Stasis can be used in conjunction with the Flamethrower to quickly dispatch Guardians, if well-timed. As soon as the Guardian releases their tentacles, use stasis on them and follow up with the Flamethrower. This method can be used to kill a Guardian with less than 20 units of flame fuel.
- On higher difficulties, it's a good idea to conserve your ammunition by ignoring the Pods until after the Guardian is dead. With a bit of timing, you can evade the projectiles they shoot while you sever the tentacles of the Guardian, and once the Guardian is dead, the Pods won't respawn.
- One of the easier ways to kill a Guardian in Dead Space 2 is to either use Stasis or a Stasis Canister when they're alerted and the tentacles emerge. One shot with a saw blade from the Ripper will sever all tentacles, killing them.
- If you are using a Javelin Gun, you can shoot them in the torso and use it's secondary fire to dismember all tentacles. Note that using the secondary fire of the weapon uses up another javelin.
- The two Guardians in Dead Space 3 eject pieces of Swarm instead of spawning pods, what makes tackling them a little easier. Line gun/Force gun combo is ideal for dealing with both of them.
- In Dead Space 3, a weapon with a Survey Charge tool can make extremely short work of either Guardian, blowing off all tentacles in a single hit.
- Due to the distance at which fighting a Guardian is preferable, it can sometimes be difficult to tell if a Guardian has in fact died or not. It is advised to wait for a few seconds to see if the Guardian ceases moving altogether, otherwise if they sprout more tentacles or does not create an audible sigh, they are still alive.
- If Isaac Clarke, John Carver (in DS3), or Gabe Weller (in Severed) comes too close to a Guardian, the Guardian will shoot a tentacle out of his chest, hitting his head and decapitating him. Because this happens so quickly, his body will try to feel what's left of the head (by reaching up to it in shock) before stumbling to the ground, claimed by death.
- Isaac's torso can also be taken out with a slash to the waist.
- The tentacles can also rip Isaac apart after decapitation, although this is a rare occasion.
- If Isaac is killed by an exploding Pod, he is thrown backward and usually has a limb or two missing.
- After dispatching a Mature Guardian, if the player listens closely they can hear the human host give a sigh of relief at the end of the creature's death animation.
- Premature Guardians are far more human in both appearance and the sounds they make. They have demonstrated themselves to be capable of rudimentary vocalizations, such as screaming in pain if Isaac gets too close and the tendrils are forced to move by the Corruption. Additionally, if the player listens carefully to the sounds made by an inactive premature Guardian, one cry sounds vaguely like the word, "Help," demonstrating a level of consciousness and human thought.
- The Tentacle that a Mature Guardian uses to dispatch Isaac's head seems to originate out of the mouth of the Guardian.
- A Guardian's wailing can be heard in a room in Chapter 2 of Dead Space (Mobile) but strangely, it is nowhere to be found. As the room is revealed to be a hallucination, it is possible that the Guardian's cry was part of it.
- If you stand in front of a dead Guardian and punch them, the blood spatter will spray forward and the screen will darken as if it were spraying in your face. This can also be done with any other body that Isaac can punch, but is easiest with Guardians as they always stay in the same position.
- Guardians seem to mature in a very short amount of time. The second time Isaac enters the Medical Deck on the Ishimura, he encounters a few Guardians that weren't there the first time despite it only being a few hours.
- The Guardian's instant-kill attack is a proximity-triggered script rather than a property of the creature himself; it is thus not affected by Stasis and will come out instantly even if the creature is slowed down.
- In Dead Space, the melee attack grants immunity to certain triggered states, including running out of air and a Guardian's instant kill trigger. This immunity only lasts until Isaac stops performing repeated melee attacks; it is possible to melee-step towards a Guardian and kill them, but as soon as the player does anything but another melee attack, Isaac will die instantly as if hit by the tentacle.
- No premature Guardians are seen in Dead Space 2 and 3.
- A premature Guardian can be seen floating in Dead Space: Salvage . Oddly enough, he is not attached to any wall. This could simply be a creative error made by the artist.
- Guardians in Dead Space 3 still scream as if the host was conscious, despite the crew being dead for hundreds of years.
- Guardians appear only twice in Dead Space 3, which is rather strange considering that they are noticeably redesigned in both appearance and animations.
- There is a rare glitch with the Guardian with if Isaac gets close to the Guardian. Isaac's head will be cut off, but instead of it being an instant kill, he will still be able to move around as normal despite being without a head.
- The game will treat the headless Isaac as dead, thus denying saving of any kind and doors cannot be opened. Item boxes can still be interacted with.
- The headless Isaac, being dead, cannot be killed by other Necromorphs, however a death scene will still play if a QTE is initiated and failed.
- If the headless Isaac were to be killed by another Guardian, the standard animation would still play, however it will hilariously show Isaac without a head stumbling backwards from the tentacle hitting where his head once was, but now gone.
- If Isaac were to stomp or perform a melee swing, a grunt can still be heard.
- If the camera is panned towards the decapitated neck, only a very low-quality texture can be seen. This is likely because there are not many instances where a fresh human body can be decapitated, the developers did not make a detailed gore of that section.
- Only one Guardian can be seen in Dead Space 2: Severed, and is assisted by Crawlers
- Guardians do not appear in Dead Space Extraction or Dead Space (Mobile).
- It is interesting to note that of all the potential victims a Guardian could fight and kill off, only Isaac Clarke, John Carver, and on one occasion, Gabe Weller, were able to successfully kill off the creature(s). Given their requirements of a wall and some of the Corruption needed to grow and be sustained, it may be possible that very few people aside from these 3 have ever encountered a Necromorph of this variant.
- In Dead Space 3, the two Guardians appear to be pitch black on the PS3 version. This could indicate a major oversight from developers, as It is maybe a render error that they ignored.
- If the player is able to be near the Guardian without alerting it, they would be able to hear quiet moaning, whimpering, and heavy breathing, further suggesting it retains some human intelligence.