Portal and Character

StoryScan: Critical hit


StoryScan: Critical Hit highlights specific aspects of individual game narratives that are exceptionally well done. In this essay, we’re covering Portal (Valve, 2007), the famous puzzle-platformer included with the Orange Box. This essay will cover content up through the end of the game. Players who have not completed the game may want to set this article aside until later, as it contains substantial spoilers for the main storyline.

Valve’s short puzzle-platformer became a pop-culture phenomenon, thanks in part to its clever antagonist.

If you’re a fan of video games, chances are good that you’ve heard of Valve’s classic first-person puzzle-platformer, Portal. Released in 2007 as part of Valve’s jam-packed Orange BoxPortal was designed as a short-but-satisfying bonus game for players who purchased the Orange Box for Half-Life 2 or Team Fortress 2. Instead, Portal became an overnight sensation, receiving stellar reviews and generating millions of sales1, along with a similarly-beloved sequel. While the game’s innovative portal puzzles deserve some credit for its success, much of Portal’s staying power comes from the clever premise and the bone-dry dialogue. Both factors share a common source: the game’s science-obsessed antagonist, GlaDOS. 

Portal‘s narrative is a simple-yet-effective story about one person using their wits to defeat a seemingly all-powerful enemy. In Portal’s case, the unnamed protagonist (dubbed Chell in the credits) wakes up in a labyrinthine testing facility run by an artificial intelligence named GlaDOS. At first, GlaDOS guides the silent Chell through the facility with the clinical detachment often attributed to AIs, but as the difficulty of the puzzles increases, GlaDOS reveals more of a personality—and it’s a mean one. She’s sarcastic, capricious, and cruel, and she’s also leading Chell towards certain death. It’s only thanks to Chell’s cleverness that she’s able to escape, at which point she starts searching for GlaDOS, and the hunter becomes the hunted. While the basic premise has been done countless times before, the unique setting and characters keep such well-trodden territory feeling fresh. GlaDOS plays a vital role in creating this feeling, as she’s both the antagonist and the primary source of dialogue. That’s a heavy load for any character to carry; with lesser writers, GlaDOS might have fallen flat. Instead, GlaDOS is remembered as a beloved gaming icon thanks to her rivalry with Chell, her all-too-human emotions, and her dry wit. 

Making the Impersonal Personal

Antagonising a Silent Protagonist

Chell is presented as a voiceless, faceless protagonist, but players who get clever with portals can view her from head-on.

Silent protagonists and their antagonists have an interesting relationship. Typically, antagonists are designed to oppose the protagonist’s beliefs and ideals, but silent protagonists rarely have either of those things. They’re designed to be player stand-ins, which means they either believe what the player does, or their beliefs don’t matter to the story. The former works well in choice-driven games, where the player’s actions impact the narrative, but Portal’s story has no branches. This lack of player choice may be why the protagonist, Chell, is a blank slate whose only priority is survival. It’s a universal desire, one all humans share, and it’s a simple desire to antagonize. When a protagonist only cares about survival, all the antagonist has to do to oppose them is try to kill them. This is where Portal’s GlaDOS shines. As an artificial intelligence designed for conducting scientific tests, GlaDOS cares more about testing than she does about human life. This drive to test makes her the perfect opponent for Chell, who cares about her own life more than she cares about completing GlaDOS’s tests. She doesn’t need to talk to express that, either; every action she takes to ensure her survival runs is an act of war against GlaDOS, and GlaDOS must strike back to get the rest results she desires.

Chell’s desire to survive is the primary source of her conflict with GlaDOS, but GlaDOS has other ways to make their impersonal conflict feel personal. Chell may not feel the need to speak, but GlaDOS does, and she’s got a wealth of information to use to her advantage. More specifically, she’s got information about Chell: who she is, where she came from, and how she ended up in the testing facility. Chell doesn’t remember any of these things, so GlaDOS can use this information to manipulate her into completing the tests. Once again, GlaDOS shows that she can use universal human desires to her advantage—not just the desire to survive, but the desire to have a sense of history and to belong. These are the desires that transcend the physical; they’re desires that come from emotions, and no one understands emotions like GlaDOS.

The Emotions of Machines

GlaDOS’s body is made up of a series of cores that regulate her impulses and emotions.

GlaDOS is a master of emotional manipulation, especially when it comes to her human test subjects. It’s not enough for her to test someone’s physical limits; she also wants to test the limits of their minds. To this end, she preys on her subjects’ emotions by using their weaknesses against them. The best example of this tendency occurs about halfway through the testing gauntlet when GlaDOS gives Chell a Weighted Companion Cube: a grey and white cube with hearts on the sides. It’s a faceless, voiceless object—much like Chell in the first person—but GlaDOS makes a point of personifying the cube so Chell will bond with it. Even though the Companion Cube can’t talk, GlaDOS insists that the cube brought Chell luck and is a good ally. Then she asks Chell to dispose of it in a pit of lava. “While it has been a faithful companion,” GlaDOS says, “your companion cube cannot accompany you through the rest of the test. If it could talk – and the Enrichment Center takes this opportunity to remind you that it cannot – it would tell you to go on without it because it would rather die in a fire than become a burden to you.” It’s an incredibly cruel request, especially for a lonely human who’s been trapped in a testing facility without any friends, and it adds a personal dimension to an otherwise impersonal rivalry. GlaDOS isn’t just trying to destroy Chell’s body; she’s also trying to destroy Chell’s mind. 

GlaDOS is a master of manipulating human emotions, but she’s hiding more than a few emotions of her own. Even though she’s an artificial intelligence (something further explored in Portal 2), she’s capable of feeling annoyance, relief, fear, and rage. She does a fine job of concealing these emotions while her tests are going well, but the cracks in the facade start to show once Chell exhibits signs of defiance. By the time Chell escapes the testing chamber, GlaDOS is in a full-blown panic, shifting strategies with wild emotional swings. In the span of one line, she shifts from asking: “What are you doing? Stop it! I-i-i-i-i-…” to proclaiming: “Weeee are pleased that you made it through the final challenge where we pretended we were going to murder you. We are very very happy for your success.” Her anxious tone makes the statement even harder to believe than it already was, and that anxiety continues to escalate as Chell hunts GlaDOS down. By the time Chell reaches GlaDOS’s chamber, the beleaguered bot has demonstrated a full range of human emotions—more than Chell has shown herself. She’s also demonstrated another uniquely human attribute that sets her apart from her enemy: a wicked sense of humor. 

Killer Jokes

GlaDOS uses understatement and sarcasm to create comedy, like when she insists the inanimate Companion Cube will never try to stab you.

If there’s one detail that can be said to define GlaDOS above all others, it’s her deadly wit. Her robotic voice makes her a natural at the deadpan delivery, and she can combine that flat affect with absurd levels of understatement to make her chilling lines disturbingly funny. These understatements begin early on, with seemingly-innocuous warnings like: “Please be advised that a noticeable taste of blood is not part of any test protocol, but is an unintended side effect of the Aperture Science Material Emancipation Grille, which may, in semi-rare cases, emancipate dental fillings, crowns, tooth enamel, and teeth.” Between the flat delivery and the scientific vocabulary, it’s almost possible to miss that GlaDOS is telling Chell that her teeth could start falling out in the most painful way possible. These warnings ramp up in both frequency and intensity, with GlaDOS warning Chell of potential “permanent disabilities, such as vaporization,” and “unsatisfactory mark[s] on your official testing record, followed by death.” Such understatements made it clear that GlaDOS is not just indifferent to Chell’s survival but indifferent to human suffering altogether—unless it’s a source of comedy. 

Like the rest of GlaDOS’s emotions, GlaDOS’s sense of humor develops as Chell makes her way through the testing facility. Once Chell breaks out, posing a direct threat to GlaDOS, GlaDOS’s urge to tell jokes becomes more transparent. She teases Chell about Getting lost, saying: “You should have turned left before. It’s funny, actually, when you think about it. Someday we’ll remember this and laugh- and laugh- and laugh- Ohhh Boyyy.” When that doesn’t stop Chell from attacking GlaDOS head-on, GlaDOS floods her chamber with a deadly neurotoxin, then lets loose with a robotic cough. “Neurotoxin… *cough* So deadly… *coughs* Choking… Hahahaha…I’m kidding. When I said ‘Deadly Neurotoxin’, the ‘Deadly’ was in massive “sarcasm quotes”.…Honestly, it’s not deadly at all. To me… You, on the other hand, are going to find the deadliness a lot less funny.” With the neurotoxin flooding the room, there’s no real reason for GlaDOS to be cracking jokes, but she’s doing it anyway because she’s afraid the toxin won’t be enough. Her razor wit isn’t just a tool she uses to disarm test subjects; it’s also a defense mechanism, one that makes her all too human. 


It’s been almost fifteen years since Portal first arrived with the rest of the Orange Box, and GlaDOS is still remembered as one of the greatest video game antagonists of all time. Thanks to her well-constructed rivalry with Chell, her emotional range, and her sense of humor, GlaDOS lives on in the memories of everyone who has ever played the puzzle-platformer. Developers who wish to write compelling antagonists should look to GlaDOS as an example of how to oppose silent protagonists with the kind of style and humor that can endure for generations.

Further Reading

StoryScan: Far Cry 5 and Character

Far Cry 5’s use of a silent protagonist hamstrings the development of the other characters.

Narrative Analysis:

How characters express themselves, using spoken or written words.

StoryScan: Team Fortress 2 and Paratext

Team Fortress 2 uses paratextual videos and comics to overcome the storytelling limitations of the genre.


Portal – Reception.” Wikipedia, 2022. 

* Reference Script: Ayelis. “Portal – Game Script – PC.” GameFAQs, 2009. 

** Reference Footage: Giedmich. “PORTAL | Full Gameplay Walkthrough | No Commentary.” YouTube, 2017.