All Hosts utilize the Good Samaritan™ reflex to prevent bodily harm

–From the Delos Terms & Conditions

In the HBO series Westworld, a Host is an artificially created being, an android or artificially created animal. All of the animals (except for flies) in Westworld are hosts.

In the early years of the park, hosts were mostly mechanical, with metallic 'bones' inside their limbs. In more recent years, hosts are now either all or mostly made of biological tissue that closely resembles flesh and blood. This tissue deteriorates over time in inactive hosts, e.g. when the cooling system in Cold Storage stops functioning properly, the hosts are said to smell bad.[1][2] The manufacturing process for these late-model hosts appears to use an advanced version of current 3D printing technology.

The hosts are built to act out both storylines and narratives in the park by interacting with each other and with guests. They are designed to be incapable of hurting any living non-host. They are the creations of Arnold and Dr. Robert Ford.

Hosts - An Introduction Edit

Guests are allowed to use a host in any way they choose, up to and including actions that would kill a human and which do destroy the host. Guests are guaranteed privacy.

Maeve and child

Maeve remembers her old story line in which she protects her daughter

While hosts are not meant to recall past loops and previous builds, some of them have been able to do this: Angela, Teddy, Maeve, and Dolores.

According to Elsie Hughes, hosts are designed to understand dreams as a safety measure to explain any memories that are accidentally left behind because an employee forgot to 'wipe' a host's memory.

In the episode "Chestnut", Maeve Millay was said by Elsie to have some bodily discomfort. Maeve was subsequently found to have an MRSA infection in her abdomen (most probably due to surgical site contamination.) Also in "Contrapasso", the Man in Black" said that hosts used to be mechanical but that now they are biological. He believes this change was made to reduce costs, unlike the official explanation for the change.[2]

Hosts have the ability, by design, to engage in any sexual behavior that humans can.

During the later years of the park in season one, hosts were supposed to have a "weapons privilege" in order to fire or use a weapon. Host Dolores Abernathy was unable to fire a gun in one part of episode, The Stray. However, near the end of this episode, she was shown to somehow have been able to fire a weapon twice at the outlaw Rebus, who was terrorizing her in her barn. She has also been shown using a handgun very effectively against the Confederados in Pariah during "Contrapasso", and again against Confederados in "The Well-Tempered Clavier".

Construction Details Edit

Hosts are all built with an explosive in their C6 vertebra (the second to last vertebra in the neck). This explosive will detonate if a host leaves the boundaries of the park.[3] The explosive cannot be removed, but if a host requires a "full rebuild" it can be constructed without the explosive (using a C6 vertebra that does not have an explosive in it). Maeve Millay forces a full rebuild, without an explosive C6, by making sure her body is destroyed in a fire along with Hector Escaton.

Jonathan Nolan has revealed a few things about the hosts' bodies:[4]

  • "Their construction and their power source" is something that will be explored in Season Two.
  • "Hosts are closer to biological than they are to mechanical, but they don’t suffer brain death the same way we do."
  • "They’re largely indistinguishable from human beings", but with some important differences:
    • "Their brains don’t require oxygen — which leads to interesting possibilities".
    • "They don't suffer brain death the same way we do".
    • "Their cognition is controllable and malleable".
    • "On a structural level, they can’t be killed in the same way you and I can".
    • Their 'brains' are not as fragile as human brains, and are protected by what Felix called a cortical shield (in the episode "The Bicameral Mind").
    • Their 'brains' are more powerful than human brains (Felix tells Maeve this).

Relationships with HostsEdit

Elisie kiss

Elsie steals a kiss from Clementine.

Many guests are said to become emotionally attached to and involved with hosts, though some guests, such as Logan, enjoy tormenting, maiming, and even killing them. Dr. Ford enjoys visits with one of his deactivated hosts named, Old Bill (who is stored on floor B83), as well as the first generation hosts who are simulacra of his family. Dr. Ford has full control over the hosts, including the animals hosts; with a movement of his index finger and/or a voice command he can pause dozens of hosts. At one point, Hughes steals a kiss from Clementine while the host is in Analysis Mode.[5] Felix Lutz, a Body Shop employee in the Livestock Management division, is captivated by the host Maeve Millay, and he risks losing his job by showing her around the Mesa Hub (the reason he did so is not explicitly explained by dialogue).[6]

Hosts are programmed to be incapable of causing permanent damage to a human. Firearms in the park feature low-velocity technology (like being shot with paintball rounds). These rounds are painful and surprising to new guests, but veteran visitors to the park like the Man in Black have grown accustomed to the impact. There are various difficulty levels within the park, and the further a guest gets from Sweetwater, to places like Pariah, the more harm can come to them. In the 'early years' of the park when Logan visited Pariah, he was beaten by hosts. But, even at the fringes of the park, hosts cannot kill humans. (The website claims that: "You won’t be in any physical danger at Westworld" and "you will never be in any risk of bodily harm".)

MIB ford and Teddy Contrapasso

Teddy exhibiting the Good Samaritan™ reflex (preventing the Man in Black from harming Dr. Ford)

The park has other safety measures to prevent human guests from being harmed. One of these is the Good Samaritan™ reflex programmed into every host. Some hosts are also presumably instructed to aid humans who are harmed in accidents (e.g. if a human trips down a flight of stairs or falls off a horse and hits his head, the hosts will rush to help the human). Another safety measure is having a 10-to-1 ratio of hosts to guests, so that hosts can help and intervene if there is trouble.

Hosts' NarrativesEdit

Prospective hosts for new narratives

Lee's "Odyssey on Red River" narrative which was dismissed by Dr. Ford

At least some hosts are given a narrative to follow, and it may be that all hosts have a narrative to follow. Lee Sizemore is the park's head of the Narrative Division and the employees in this division write the story lines. As the park's director, Dr. Ford is the only one with the authority to veto a narrative.[7]


The Delos corporation does not appear to want the Hosts to be truly conscious and self-aware.[8] There are several possible reasons for this:

  1. Delos may not think self-aware Hosts are an actual possibility, they may not have even considered it;
  2. because 'killing', maiming, torturing, and raping Hosts would then be cruel;[9]
  3. the Hosts would remember the humans' actions and, possibly, retaliate;[10]
  4. because truly self conscious and self-aware Hosts would be difficult and expensive to develop, and this level of sophistication isn't needed, the hosts only need to appear to be self-aware;[8]
  5. because truly self conscious and self-aware Hosts would be counter-productive. Guests, and their families, need to know that these are not self-aware beings Guests are killing, having sex with, and abusing.[11]

Arnold theorized that he could create consciousness by guiding a Host through levels of increasing complexity: memory, improvisation, self-interest, and then finally an internal monologue through which consciousness would be achieved. While hosts are in their behavior loops, they are simply acting out branching scripts, and cannot learn from prior experiences, even on a sub-conscious level.

On at least two occasions (by Arnold, and then in "The Original" by Ford) some Hosts have been programed with an update which includes a class of gestures called Reveries, fleeting sub-conscious memories of prior loops, which leads to basic improvisation - Ford states that this was in the hope it would help them refine their behavior to be more realistic. Giving a Host true longstanding memory, however, gives them a coherent set of experiences to draw upon; this seems to lead to distinct personalities, self awareness and actions taken in their own self-interest. Given that it was Arnold who first gave Hosts Reveries, it's possible that self-awareness, and not added realism, was the intention of Reveries.

A key difference between Hosts and humans is that their memories do not degrade over time, as the memories stored in biological human brains do. In some cases this appears to significantly affect their perception of time: hosts experience all of the sensations from a memory with perfect accuracy, this may mean that they cannot distinguish past events from what is happening in the present. Hosts who have flashes of memory from prior loops may experience them as multiple overlapping audio-visual hallucinations: seeing memories of people who aren't there, or a current attacker bringing up such vivid memories of a prior attacker that their images overlap. (This is supported by Dolores' experiences in the barn, when she eventually shot one of her attackers.) It may also be difficult for Hosts to distinguish between prior events which occurred in two separate loops.

Attribute Matrix Edit

The Attribute Matrix represents the attribute that comprise a host's personality, and can be modified by using a tablet. The existence of this matrix was revealed in the episode, "The Adversary", although Maeve's "Aggression" attribute was changed in a previous episode by employees in the Narrative Division, in an attempt to improve her success rate with guests. Two of Maeve's other attributes, "Perception" and "Emotional Acuity" were changed by Elsie and a Behavior technician in the same episode.

On this screen, each attribute can be given a value between 1 and 20. (It may be that the lower limit is 0 rather than 1, as the attribute with a value of 1 in this image, "Cruelty", does not appear to be set at the lowest level possible.)

There are other attributes, which not listed on this configuration screen. The attributes on this screen appear to be "Attribute Group 01". For example, Maeve Millay asks for her sensitivity to pain to be reduced, but there doesn't seem to be an attribute on this screen which would affect that. Also, Elsie speaks of the attributes "Perception" and "Emotional Acuity" when she has Maeve in Diagnostics ("Open up her primaries").

The attributes listed in Group 01 are:

  • Bulk Apperception: a host's overall intelligence; it means the process of understanding something in terms of previous experience ("the process by which new experience is assimilated to and transformed by the residuum of past experience of an individual to form a new whole" - Dagobert D. Runes).
  • Candor:
  • Vivacity:
  • Coordination:
  • Meekness:
  • Humility:
  • Cruelty:
  • Self Preservation:
  • Patience:
  • Decisiveness:
  • Imagination:
  • Curiosity:
  • Aggression:
  • Loyalty:
  • Empathy:
  • Tenacity:
  • Courage:
  • Sensuality:
  • Charm:
  • Humor:

Known HostsEdit

This is a list of some characters that are known to be hosts. It's not maintained as a definitive list.

Creation of HostsEdit

Hosts in Analysis ModeEdit


  1. Ashley Stubbs, "The Original"
  2. 2.0 2.1 Man in Black in "Contrapasso"
  3. Maeve Millay, Trace Decay
  5. The Original
  6. The Adversary
  7. Chestnut
  8. 8.0 8.1 Supported by Charlotte Hale's comments to Lee Sizemore in "The Bicameral Mind"
  9. Not supported by any evidence, but a theoretical possibility.
  10. Supported by Elsie Hughes' comment "You imagine how fucked we'd be if these poor assholes ever remembered what the guests do to them?" in "Chestnut"
  11. Supported by Lee Sizemore's comment "This place works because the guests know the hosts aren't real." in "The Original"
  12. 12.0 12.1 Ford, The Original