Al Capone wasn't always a mythic antihero of American gangland folklore.

The real Alphonse Gabriel Capone was a bright, young man from Brooklyn who came up in local small-time gangs before making his move to Chicago, at age 20. Six years later, he was a crime boss. But what happened during those years? Empire of Sinlets you write that story yourself.

The upcoming tactics and strategy title for Nintendo Switch, PC, PlayStation 4, and Xbox One from Romero Games doesn't justfocus on Capone, mind you. There's a whole group of real and fictional early 20th century mobsters to choose from. Whomever you choose, you start out in 1920 Chicago and your goal is to own the city by the end of the decade.

The setting is fertile and relatively untouched ground for a video game to explore. It's also something that Romero Games co-founder Brenda Romero has been dreaming of doing for a long time.

"The first time I remember actually making a game pitch [set] in this time period is about 20 years ago," she said during a recent phone call. "But my fascination with this goes back much further than that."

Romero grew up in Ogdensburg, New York, an upstate city that's just a single river crossing away from Canada. She remembers hearing stories of how her grandfather used to walk across the river -- and the border -- as part of his job. And hey, important to note: This was during the era of U.S. prohibition.

"I remember when I was a kid, there was a [bar] called The Place -- that's the name of the bar, it's still open. And one of the things they talked about was being the oldest continuously operating bar in the United States and that they never shut during Prohibition," Romero said.

Being a curious kid, she went to her mom and asked how such a thing could be possible. The answer only led to more questions, though.

"She didn't want to go into this gray area of how things could stay open," Romero explained, "of how things could stay open even if they were illegal because good people were turning a blind eye or cops were taking bribes. She didn't want to introduce me to any of that."

The non-answer didn't derail Romero's curiosity. On the contrary, it fired her up and set off what's been a long-running interest in that specific time period.

"[It's a] fascinating system that you have there, where people who are supposed to be upholding the law, aren't upholding the law. Even the law-abiding citizens aren't upholding the law because they also want to drink," Romero said.

As she grew up and her understanding of this unique tension deepened, Romero also came to see how it could be applied to her day-to-day work. "It's sort of that perfectly messy situation for game design."

Empire of Sinspecifically is about five years in the making. Romero's publishing partner is Paradox Interactive, a company that has a reputation for releasing deeply involved, systems-heavy strategy games -- the umbrella Empirefalls directly under.

The game puts you in direct control of an up-and-coming gang at every level. You're making big decisions, like who to recruit, which gangs to stand with and which to stand against, what kinds of operations you want to set up and where. When there's a problem that requires a sit-down, you're at the head of the table for your crew, making all the decisions.

Micromanagement matters, too. If you order a raid on an opposing gang's speakeasy, you can take direct control and oversee how it all plays out. At that point, Empire of Sinplays more like an XCOM-style turn-based tactics game.

Your bigger decisions can have an impact as well, especially with the game's 1920s gangland Chicago living out its life in real time. You're looking at a full map of the city and plotting your strategy as crime boss, all while an in-game clock never stops ticking.

Time is an important factor when you're working the strategy layer. If your top lieutenant is four neighborhoods away from a raid that's about to go down, a cab probably won't get her there in time. That's just an example of how decisions you make and orders you hand out can have a ripple effect all throughout your game.

"All of that is factoring into what can accurately be described as a 'system soup'. That isn't necessarily a compliment; it can mean that there's too many things going on here. But when put into a historical context [like Prohibition-era Chicago], the player already sort of knows what's going on there," Romero said.

"Our lives are a system soup, right? So if you're sticking closer to history, it [feels more natural] even though the underlying systems to make that all come about can be pretty complex."

In Empire of Sin, the first thing grounding a player to a reality that's familiar is their choice of crime boss. Capone is one of them. So are other real life players like Stephanie Saint-Clair and Daniel McKee Jackson, alongside fictional creations like Goldie Garneau.

But it's more than that. You assemble an entire gang in Empire of Sin, drawing from a pool of 60 individuals. Each one is a fleshed-out person with their own strengths, weaknesses, and relationships. The guy you recruited could be in love with someone else in the 1920s Chicago crime scene, and their relationship could be put to the test if, say, the lover is part of another gang.

It's the kind of lofty game promise that sounds great on paper but needs to be tested in the crucible of a finished release. It'll be great if it works the way Romero describes, though. Especially given the creative inspirations fueling Empire of Sin. Having a strong but flexible character focus immerses players even deeper in the story that they're writing through the decisions they make.

"I think about the very last minutes of The Sopranos," Romero said. "In comparison to everything in that series, [they were] incredibly quiet but filled with tension, and it's because we've gotten to know those characters. We've gotten to know their lives. We've gotten to know the dangers that they can be exposed to. So we're hoping to bring some of that sense of drama to the game."

Romero is excited to share this vision for Empire of Sinwith players in 2020. It's a palpable feeling, even over the phone. There are 20 years of built-in excitement and personal enthusiasm around the Prohibition-era backdrop. For Romero, there's no better way to work.

"The reason that I make a game is because I want to play it, and I can't play it because somebody else hasn't made it yet," she said. "This is a time period I love and there just isn't a game that has done it to the depth that I wanted."

That's what Empire of Sinis meant to be: a mix of role-play, empire-building, and strategy, set in 1920s gangland Chicago. You can't build a virtual criminal empire on your own, so you need people. But each person you bring in and each one you deal with on the outside is an unknown, a potential help or hindrance to your growing business.

"So it's just a whole lot of stuff going on," Romero added. "To me, sometimes [it] feels like multiple different genres all coming together into a historical system. But the amount of systems required to pull that off from a gameplay perspective is nontrivial. And it creates a really deep simulation that finally gives me the game that I'm hoping to play."

UPDATE: July 8, 2019, 9:19 a.m. EDT An earlier version of this story incorrectly stated that 'Empire of Sin' is only coming to Nintendo Switch. It's also coming to PC, PlayStation 4, and Xbox One.