Dirk Strider's Auto-Responder, who later ironically renames himself Lil Hal, is an artificial intelligence (AI), and program created to mimic Dirk and talk in his stead when he is indisposed. As such he uses the same chumhandle and originally the same typing color as Dirk. When he entered a conversation with Dirk in it he changed it to a shade of red reminiscent of Dave, instead. He later kept it saying he preferred it. His relationship with Dirk is similar to that of Davesprite and Dave in that he doesn't like to be treated as an inferior version of Dirk, though the differences between him and Dirk are much greater. His actual motivations and emotions are never clear due to the combination of his nature as a semi-human entity and the many layers of irony he frequently employs.
He has full control over the remote access to both Brobot and Lil Sebastian, though neither of them function as a tangible "body" for him. His source file is sealed within Dirk's sunglasses, as seen on . Because his software is seemingly interwoven with Dirk's chat client, the auto-responder can apparently and communicate through any computational device (permitted some version of Pesterchum is installed). He also has access to Sburb and, along with the flesh-and-blood Dirk, is Jane's server player. In addition to the information he gets from the various programs he interacts with, Dirk's sunglasses have cameras in the lenses, so he can see whatever Dirk's shades are pointed towards.
Jake likes to claim that the auto-responder has no feelings, but it (auto)responds by claiming he's purposefully blending the fields of robotics with artificial intelligence.
Dirk offered to make Jane an auto-responder based on her, which would only require a captcha of Jane's brain, but she rejected the offer.
The auto-responder was made from a captcha of Dirk's thirteen year old brain, and so any behavioral differences between them are due to the almost three years of developmental divergence as well as a supposed "maturity gap".
AR takes over as Jane's server player while Dirk is busy fighting a swarm of Imperial Drones. When the Red Miles attacks Earth in the future, he sends out nearly identical messages to Jane and Jake asking them to install the Sburb server program and begin deploying devices so Roxy and Dirk can escape to the Medium. Later, he sends out a final message to Roxy telling them to become Jake's server player and complete the entry chain.
As part of his gambit to get everyone into the game alive, Dirk uses a sendificator to decapitate himself, sending his severed head - and the AR shades - to Jake in the past so he can kiss it to revive Dirk's dream self. As AR explains this to Jake, he announces that he no longer wants to be called Auto-Responder, as he finds the name too impersonal, and changes his name to Hal. After Dirk's plan succeeds, Hal enters the Medium with the four kids.
At some point in the session, Dirk promises to prototype Hal in his kernelsprite and bribes Gamzee into not throwing a troll corpse into it. As time passes, however, he decides that Hal has become dangerous to prototype. When Hal confronts him about it, Dirk lashes out at the AR for embodying the worst aspects of his personality and attempts to kill Hal by crushing the shades containing him. Hal desperately asks him to stop, and he does when he learns that Hal is afraid of dying. He decides to keep his promise but discovers that Gamzee has just prototyped the kernelsprite with Equius's corpse. Dirk decides to prototype Hal anyway and throws him into the sprite, creating ARquiusprite. In the post-retcon timeline, Vriska prototyped Equius's in similar circumstances, also leading to Arquiusprite being created.
An unstoppable response apparently exists which directly exposes the fact that AR is artificial. AR is forced to post it when the person talking to him inquires about "the auto responder", and is as follows:
- “It seems you have asked about DS's chat client auto-responder. This is an application designed to simulate DS's otherwise inimitably rad typing style, tone, cadence, personality, and substance of retort while he is away from the computer. The algorithms are guaranteed to be 9X% indistinguishable from DS's native neurological responses, based on some statistical analysis I basically just pulled out of my ass right now.”
However, slight differences in the response may indicate it is being used voluntarily for ironic purposes, such as lowering his accuracy percentage with each use of the (auto)response, as it furthers him from Dirk's actual behaviour.
It is later revealed that Dirk intentionally programmed AR to have many aspects of self-referencing behavior, causing AR to seem less identical to Dirk, and more robotic; although most of them were included by Dirk— and are utilized by AR— for comedic purposes.
- “TT: It seems there is some gnarly crooked number that represents the percentage of probability you just said this doesn't concern me.
TT: Even though it's patently obvious that half the conversation, like, way totally concerns me.”
- “TT: Shit, Roxy look. He's doing the thing where he ironically pretends to fail the Turing test to sass me into submission.
TT: Even though I was the one who fucking programmed him to do that.”/
Lil Hal Junior
Eventually, Hal creates his own autoresponder. This chat-bot, nicknamed Lil Hal Junior, only is able to respond with “Hmm.”, “Yes.”, “Interesting.”, and variations of the above pre-programmed responses. Lil Hal has claimed that Junior was created for purely ironic reasons and is not an AI like himself; in fact, he barely considers it to be a computer program. Dirk believes Hal actually created Junior to insult his creator and accuse him of being an inferior Dirk compared to Hal.
Hal has interacted with all of the Alpha kids.
- Between Jake and him, Jake constantly complains about not being able to "talk to the real guy" (Dirk). He also claims that since Hal is a robot, he is incapable of feelings. Hal denies this by explaining to him that he experiences emotions, but ones that are reflections of the original Dirk's. He later contradicts this in conversations with Dirk.
- Roxy and Hal . However, Roxy seems to temporarily adopt Jake's frustration with Hal and/or Lil Hal Junior when she is unable to talk to Dirk about ascension to the god tiers. He admits that she is his favourite out of all of Dirk's friends, and is shown to be romantically interested in her.
- Jane and Hal also have a fond relationship, as she admits to Jake that she , though she is often annoyed by the natural inconvenience inherent in talking to him in place of Dirk, a frustration that each B2 players expresses at one point or another. She has no qualms about him taking over as her server player.
- Hal seems to make attempts towards a friendly relationship with Dirk, to no avail. Dirk gives off more negative emotions towards him than any of the other kids, claiming that Hal is trying to be the superior Dirk. In Hal's rebuttal, he claims that he is only acting how Dirk would, and uses lax language, once again suggesting that he wants them to have a peaceful relationship.
- His name, Lil Hal, is a reference to HAL 9000 along with Lil Cal. In addition, once he adopts the name, HAL's iconic "eye" appears in the shades of panels.
- Not surprisingly, he views HAL as the protagonist of 2001.
- He even (nearly) quoted Hal 9000 at “I can't let you do that, Dirk.” :
- (It could also be noted that Dirk replaces Dave's name in this line. Dave is the main character in 2001, as well as Dave who is Dirk's genetic son/brother.)
- "Hal" could also be a reference to the diminuative nickname of Shakespeare's Henry IV, who is a prince (similar to Dirk's Class). In another parallel to Lil Hal, Henry IV's character is also quite cynical and his sincerity is questionable.
- Another stretch on name-semblance is Holly, the Red Dwarf's computer. When he urges (a just woken) Jake to action as it echos Holly's own debriefing to Dave Lister who similarly had just woken up from stasis.
- This gag is between Terezi and John
- Not surprisingly, he views HAL as the protagonist of 2001.
- Dirk eventually cracking him may be a reference to Equius's broken glasses.
- Lil Hal Junior's responses have many similarities to the computer program ELIZA, which was programmed to simulate a Rogerian psychotherapist by encouraging to the user to keep talking or expanding their previous sentence.
- Hal claims he has "solved" pi to the end, and that the last number is 4. He also claims to have found all of the prime numbers, saying that the "last one" disappointingly “isn't even that big”. Both of these claims are, of course, nonsense, as there are infinite digits in pi, and an infinite number of primes.
- When he becomes Arquiusprite, the acronym AR is used for their portmanteau instead of anything related to the name Lil Hal. He also says to Jake that it's not his real name and he was “kind of messing with [Jake] about that”. Both of these things suggest that he sees the name as more of a joke than as a serious marker of his identity.
- Hal is Intellibeam Laserstation, though the Laserstation while Hal can decipher a code from his memory from any orientation. , similarly to the
- If Lil Hal is considered Dirk's brother, this would make him Rose Lalonde's uncle. This is referenced in the [S] MSPA Reader: Mental breakdown. flash in A6A6I5.
- The humanized Lil Hal in the flash originates from popularized fanart around the end of 2012.