The first Portal game was an instant classic, spawning a great many memes following its release in Valve's bundle package The Orange Box in 2007. It was hailed as one of the most original games of the year because of its unique physics-based puzzle gameplay, revolving around the use of—you guessed it—portals. There's a lot to love about Portal, but perhaps its most enduring success was the introduction of the game's villain, an AI named GLaDOS.
GLaDOS' sarcastic and deadpan humor made the original game not only unique and interesting to play, but also devastatingly funny. Her personality and motivations were expanded on in Portal 2, and her brand of humor and aesthetic have become the foundation for the franchise. However, she is still the villain, and has done some terrible things. We're looking at some of the worst from her long list of crimes.
10 10. Bullies Chell
GLaDOS is obviously contemptuous of humans from the outset of the first game, but it becomes really personal after Chell (the protagonist of both entries) defeats her at the end of Portal. After all, Chell did murder her. Never mind that GLaDOS tried to kill her first, of course. And to work out some of that aggression, GLaDOS spends the majority of the first part of Portal 2 insulting Chell about anything she can think of. Her trusty defaults are a) call Chell fat and b) mock Chell for being an orphan. That's pretty mean.
9 9. Burns the Companion Cube
So technically you drop your beloved Companion Cube into the incinerator yourself. After being your trusted friend and confidant throughout Test Chamber 17, the only way to progress past that point is to euthanize your Cube. We think it's actually worse that she makes you do it yourself. Then in Portal 2, now that she's got a grudge against Chell personally, she tells us the Companion Cubes are sentient, but they're worthless—they have warehouses full of them, even. Just to rub salt in the wound.
8 8. Lies To Chell
GLaDOS is lying to Chell constantly. Probably the most recognizable example of this is the ubiquitous meme spawned from the first game: "the cake is a lie." Throughout the testing procedure, GLaDOS promises that following the final test, Chell will be escorted to a party and will be given cake.
She also lies in Portal 2 about having found Chell's birth parents, and that they're all throwing her yet another party. You have to assume Chell doesn't actually buy her story anymore, but that doesn't stop her.
7 7. Tries To Turn Atlas and P-body Against Each Other
Portal 2 also contains an entirely separate co-op story set after the events of the main game. With Chell out of the picture, GLaDOS enlists two android test subjects—Atlas and P-body—to complete a new series of test chambers together. She eventually started trying to pit Atlas and P-body against each other, implying that they had reported on each other behind their backs, or that they had previous test partners. Luckily, the bond between the two robots was too strong to sever.
6 6. Imprisons Rattmann
Following the fall of Aperture Science, only a few individuals managed to survive. Doug Rattmann, a programmer suffering from schizophrenia, was perhaps the only one who lasted any length of time. Due in part to GLaDOS' total control over the facility and to the invasion of Earth that happened only a few days later, Rattmann was unable to escape the facility and took to hiding in the walls from GLaDOS. He began rationing his antipsychotic medications, which led to his schizophrenic symptoms worsening, resulting in the many scrawled messages you can find throughout Portal and Portal 2.
5 5. Destroys Atlas and P-body
GLaDOS really doesn't go easy on these poor androids. They can be catastrophically injured at multiple point during their testing courses and, often, their partner will just have to stand and watch their friend explode into pieces.
Luckily, the reassembly units are able to create a fresh android as soon as one breaks. However, this leads to GLaDOS abusing the ability to force a self-destruct, sometimes destroying an android for no reason at all.
4 4. Tries To Kill Chell Multiple Times
This probably doesn't surprise anyone, as it's a major plot point of both games. But GLaDOS tries very hard to kill Chell on more than one occasion. She fills courses with live fire turrets, she tried to burn her alive, she flooded her chamber with neurotoxin. At the end of the first act in Portal 2, she does everything she can to kill Chell before she can replace GLaDOS' core with Wheatley's. Without Chell's tenacity, she'd be dead like twelve times over by now.
3 3. Deletes Caroline
A major revelation over the course of Portal 2 is that GLaDOS was created at least partially from the consciousness of Cave Johnson's assistant, Caroline. It's heavily implied that Caroline was forced to become the AI and that some of GLaDOS' murderous actions may have been a form of revenge.
However, over time it seems that GLaDOS buried the part of her that used to be Caroline in an attempt to escape human emotions. Once she rediscovers where Caroline's personality is stored, instead of learning an important lesson about the value of humanity, she deletes her. Goodbye, Caroline.
2 2. Kills Hundreds Of Test Subjects
At the end of the co-op storyline, GLaDOS enlists the help of Atlas and P-body to "rescue" hundreds of test subjects that have been preserved in a cryogenic vault somewhere deep beneath the facility. Now with so many test subjects to use, she destroys and abandons the androids. However, in the additional testing course "Art Therapy" she reconstructs the androids, informing them it's been 100,000 years since they were last assembled. In reality, it's only been a week and she's already killed all her new human subjects.
1 1. Flooded Aperture With Neurotoxin
The inciting incident for the Portal franchise happens after Aperture foolishly put a rogue AI in charge of the entire facility. Given free reign, GLaDOS immediately flooded the entire Enrichment Center with a deadly neurotoxin, killing almost everyone inside that wasn't cryogenically preserved. Now, Aperture certainly wasn't the most ethical of companies. But the wholesale slaughter of an entire complex full of people is probably far and away the worst thing GLaDOS has done.