There’s a line in Mass Effect 2 where a gunnery sergeant says, “Sir Isaac Newton is the deadliest son of a bitch in space.” He’s not wrong - but he’s not necessarily right, either.

When the sergeant says this, he’s referring to Newton’s first law: an object in motion stays in motion unless acted on by an outside force. His point is that when you fire a slug in space, it will travel until it hits something. Maybe it will be another ship, or a distant planet, or someone located 10,000 years in the future in deep space. There’s no real way of knowing.

While Newton’s law is, in this case, linked to extreme deadliness, the title of “deadliest son of a bitch in space” rightfully belongs to someone else: EDI.

Mass Effect 2 and 3 writer Chris Hepler tells me that EDI is very different to Legion, Commander Shepard’s only other non-organic squadmate in the original trilogy. This is important given that Mass Effect largely centres on the relationship between organics and AI: there are different kinds of AI, and - unlike in a lot of other sci-fi - they’re not defined by a tropey desire to become human.

“Legion is essentially humorless, a collective consciousness, and created by aliens – he's harder to relate to,” Hepler explains. “EDI, on the other hand, is the brain of the Normandy that gets a human-shaped body and wants to try it out. So wherever Shepard asks a lot of questions of Legion, EDI asks more questions of Shepard.

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“EDI is also rare among most sci-fi robots in that she already has a pretty good read on humor, and does deliberate deadpan jokes a lot. That helped break her out of the mold of the always-helpful virtual assistant that talks you through missions in dozens of other video games. One of EDI's earliest jokes in ME3 was to reassure Shepard that she ‘only forgets to recycle the Normandy's oxygen when she's discovered something truly interesting.’ Shep's disturbed expression says it all.”

Although we get to know EDI throughout Mass Effect 2 and 3, I don’t think a lot of people recognize just how powerful she is. This is probably because of what Hepler mentions - that she has “a pretty good read on humor,” which allows her character to be effectively fleshed out. But just because she can crack a few jokes doesn’t make EDI any less dangerous.

“There was a moment I was prepping for as I was writing the Cerberus Daily News, laying the groundwork for starships being used as weapons,” Hepler explains. “Basically, I wrote into the lore that they had a safety catch built into their creation, because that was how the Reapers wanted the galaxy's species to advance: starships as weapons would even the odds far too much [Editor’s note: Hepler later amended this to state that the Reapers didn’t necessarily invent FTL (faster-than-light), just the mass relays]. The result was that if you wanted to ram a Reaper at FTL speeds, you'd need either a genius who could reinvent a starship drive entirely, or an unshackled AI at the wheel who could think like a Reaper.

“In other words, the only being in the galaxy who could pull it off would be EDI, and she would do it at the climax, killing Harbinger with the Normandy. We kicked around the idea, but it didn't happen, since EDI and Joker were a big symbol for organics and AI getting along, and the Normandy's survival with them on board was a good signal to the player who chose the Synthesis ending that things were going to be okay.”

I thought the idea of starships being converted into weapons was fascinating, so I followed up. According to Hepler, Mass Effect’s dual-use of both faster-than-light travel and jump gates is brilliant, given that most science-fiction usually just opts for one or the other. However, FTL travel isn’t just about moving from planet to planet - when you’ve got the ability to project something at the speed of light, that naturally has complicated implications for weaponry.

“FTL weapons are an interesting problem in science fiction, because any star drive that can get you anywhere interesting can also be used as a relativistic weapon that hits with the force of hundreds of nuclear bombs,” Hepler says.

“The Cerberus Daily News flirted with the idea of relativistic weapons, which in any science fiction is playing with fire. Any FTL craft fast enough to go somewhere interesting can also be used as a weapon, and as the gunnery sergeant in Mass Effect 2 says, a weapon that fires a 20 kg slug at 1% the speed of light hits with the force of a nuclear bomb. So an FTL craft with a drone pilot or kamikaze pilot could probably take out most of a planet.”

Hepler explains that Star Wars attempted to riff off of this in The Last Jedi, but that Lucasfilm has always abided by “the Rule of Cool” for its space shenanigans. Nobody takes out the Death Star with an X-wing, because that wouldn’t be very cool. With Mass Effect, Hepler and the team anticipated fans to scrutinize the work more closely, which meant they needed to stitch together concrete logic for pretty much every facet of what having access to this technology means.

“So in the Cerberus Daily News, I had a terrorist crash into a [turian] city at ‘hypervelocity’ speeds but not light speed, and showed how devastating it was to a city even at just a few thousand miles per hour,” Hepler says. “The Citadel Council's counterterror program discovered a rogue genius physicist who weaponized FTL drives, but they nipped his work in the bud emphatically because weapons like that would upset the balance of power of the galaxy. All of the weaponizations were destroyed.

“Short-sighted considering the Reapers were coming, but politically the right thing to do for a grieving turian population - that's the Council for you. So basically, that left one being in the galaxy who had the motive, means, and opportunity to jury-rig a star drive into a weapon, and that was EDI. Ultimately, in writing the story of Mass Effect 3, that idea was smoothed over - it was probably too much to have both Shepard and the Normandy sacrifice themselves, It would've been pretty depressing if you couldn't show the companion survivors putting Shep's name on the wall and flying off into the sunset.”

Although EDI doesn’t end up sacrificing herself and the Normandy to use the ship itself as a weapon, a lot of the physics used in determining relativistic weapons still exists in Mass Effect. Hepler tells me about the Boom Table, which Chris L’Etoile used to create the approximate power of dreadnought guns back in the first Mass Effect game. This table can also be used to calculate the force of weapons like the Death Star, which would probably come out on top due to its ability to literally vaporize a planet. According to Hepler, this accounts for more energy than its official write-ups in RPG manuals afford it. These descriptions describe it as having the power of “several main-sequence stars,” although you’d need more than that to pulverize a planet.

“The Reapers' main ships have kinetic barriers that can withstand a few shots from a dreadnought,” Hepler explains. “We estimated that three to four dreadnoughts concentrating fire could bring down a Reaper main ship. The main ships were, of course, bigger and tougher than the ships Shepard and the Normandy took out, which were technically Reaper destroyers, like in the Navy term for destroyers - small ships meant to handle smaller tasks.

“We didn't have you fight a main ship, ever, other than Sovereign, who was laughing off attacks in [the first] Mass Effect until Shepard took out Saren and made Sovereign's shields blink off for a few crucial seconds.

“All this is to say... if EDI were to take out Harbinger, it'd be one hell of a bang. You would probably not want to be on a nearby planet when that shockwave hit.”

Hepler actually did the relevant calculations and sent over some exact information about what converting starships into relativistic weapons might look like. At cruising speed, the Normandy does 12 light-years a day, which works out as about 4.75 trillion kilometers per hour. This means it travels at approximately 1.31944 billion kilometers per second.

Hepler states that the Normandy’s mass is unspecified, but for argument’s sake let’s make an assumption that it’s similar to a 747. This may seem like a lowball estimate at first, given that the Normandy has multiple decks and is considerably bigger than an aeroplane, but as Hepler points out, it’s also likely to be built with much lighter materials than an ironside naval vessel. So, let’s assume the Normandy’s takeoff weight is somewhere around 443,000 kilograms.

To calculate the kinetic energy of the Normandy crashing into an object at FTL speed, we need to use the equation for muzzle energy of a bullet, which is half of the mass multiplied by velocity squared. The result is 3.856 x 10 to the 29th joules, which the Boom Table describes as being “enough energy to blow all of the Earth’s oceans off into space.” To put that into perspective, a high estimate for the force of the Chicxulub impactor - commonly known as the asteroid that wiped out the dinosaurs - clocks in at about 5.8 x 10 to the 25th joules. By my own calculations, the Normandy’s muzzle energy is over 6,600 times larger.

“So considering the collateral damage possible, maybe it's a good thing that EDI didn't hit as hard as she could,” Hepler says. It’s worth noting that he also clarifies that the idea of EDI killing Harbinger never made it past the proposal stage. It’s not that it was intact and ended up being cut - the team just decided to pursue other ideas.

Still, this is indicative of Hepler’s meticulous attention to detail when it comes to creating lore. If you read our recent piece on how Mass Effect successfully built one of the best and most logically sound science-fiction universes in the history of video games, you’ll likely already know the amount of work that went into Mass Effect’s Codex.

“Of the lore that I wrote, I liked that I didn't always take the easy way out on the weaponry,” Hepler explains. “Like, the initial press about the omni-blade was that it was a ‘holographic switchblade,’ and the early pitch was that it was made of ‘hard light’ like a lightsaber. But that made no sense - why wouldn't the Reapers, who are infinitely more advanced than us, have hard light technology all over the place? So I fudged it and said it was just a weapons-grade use of omni-gel to make a glowing-hot silicon carbide blade that didn't touch your skin because it was held in place by a mass effect field.

“That sort of request for ‘hey, we want something cool here’ came across my desk a lot, and I really enjoyed learning stuff and repackaging it as something that sounded like the coolest weapon since bread slicers. We had laser-guided lightning, shotguns that created plasma on impact, jets of molten metal, all kinds of ways to make the Reaper War sound more intense than any conflict in human history.”

But even with laser-guided lightning and jets of molten metal, EDI still holds more potential than any other being in the universe. So, all of you people who are selling t-shirts with Isaac Newton’s face on the front, with the caption “Deadliest Son of a Bitch in Space”... Well, hopefully now you understand that the title of deadliest SOB in space belongs to somebody else.

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