The current wave of virtual assistants owes a lot to a sidekick from one of the most popular video games of all time. The release of Halo: Combat Evolved in 2001 introduced Master Chief’s AI partner Cortana, popularizing a lot of the common characteristics that are now shared by real-world AI helpers. Cortana was a friendly, helpful female voice in your ear, one who blurred the line between companion and digital tool. She sounded an awful lot like Siri — and she did it a decade before virtual assistants became indispensable features of our smartphones and homes.

Halo didn’t invent the concept of an AI helper. It’s been a staple of science fiction for years, with the likes of the shipboard computer in Star Trek: The Next Generation and HAL 9000 in 2001: A Space Odyssey all playing prominent roles. But Cortana was different from her fictional predecessors in many respects, most notably that she was warm and affectionate. She’d make jokes and ensure Master Chief stayed on task, just like Siri and Alexa do today.

Cortana was different from her fictional predecessors

Starting with Apple’s Siri in 2011, the biggest technology companies in the world began introducing real-world virtual assistants into our lives. They were voices on our phones, and later other devices, that could play music, keep tabs on your schedule, remind you about flights. You interacted with them through conversation, using natural language to explain what you wanted.

And these offerings from the likes of Amazon and Microsoft largely follow the same blueprint laid out by Cortana. Siri and Alexa have female voices by default, and while they’re designed to present us with information we need or want, they also do so with a bit of sarcastic cheer. Ask Siri if she’s real, and she might quip “In the cloud, no one questions your existential status.” You’ll get similarly silly responses if you ask Alexa whether she likes pizza or if she’ll be your girlfriend. Microsoft even named its own virtual assistant Cortana, and it’s voiced by Jen Taylor, the same actress behind the video game character.

During development, the Microsoft team making Cortana the assistant even reached out to the developers of Halo for help. “One of the Cortanas is an intelligent, learning AI who is duty bound to help her companion as much as possible, using a staggering database of information combined with real, growing knowledge of that companion,” Halo franchise director Frank O’Connor explained when Cortana was announced for Windows Phone in 2014. “And the other Cortana is, well, the same thing.”

The decision to give Halo’s Cortana this particular personality wasn’t made because it turned her into a more effective AI assistant. It simply made for a better story. If she’s going to be stuck by your side for the entire game — not to mention all of the later Halo adventures — she should be someone who you would actually care about. Taylor says that, when she first started working on the game, she was directed to turn Cortana into a sort of AI girl-next-door archetype.

“They wanted her to be like the girl next door.”

“When I was initially cast, something the guys at Bungie said to me was, ‘This character is in your head all the time. She is your best guide and the best aid that you have — the only guide and the only aid really. So we don’t want her to sound naggy, we don’t want her to be a pain.’ They wanted her to be like the girl next door, your best friend that you want to hang out with,” Taylor explained in a 2012 interview with NBC.

As it turns out, what’s good for storytelling also is good for actual AI assistants. Having a friendly disposition makes us more likely to actually use these AI tools, and some researchers have claimed that users take orders better from a female-sounding voice. Actually listening to your assistant is crucial to their utility, whether they’re warning you of parasitic aliens or making sure you get to that 3:00 PM meeting on time.

This isn’t to say that Cortana is directly responsible for the wave of voice-controlled assistants that now fill our phones, speakers, and microwaves. But Bungie created a template, one that both shaped how the designers of real AI helpers approached their creations, and what we, the people who use them, expect from our digital companions. Cortana showed how this kind of AI could make life more tolerable on the battlefield: and her descendants are now trying to do the same thing for everyday life.