The Comeback of the Immersive Sim

2016 has been an interesting year, all things considered, but nothing has caught me by surprise quite like the comeback of the "immersive sim". Deus Ex is getting a fourth game later this month, and Harvey Smith is making another Thief-like stealth game at Arkane Studios. Which is also making a new Prey game which is said to be a spiritual successor to System Shock 2. Which is getting an actual successor courtesy of Warren Spector, who is also helping Paul Neurath make an unofficial sequel to Ultima Underworld. And the first System Shock is getting a remake, too.

But if you haven't heard of those games, or haven't heard of those names, or you're wondering what the hell an immersive sim is and want to know why should we care that it's getting a huge revival, then... this is Game Maker's Toolkit, I'm Mark Brown, and in this episode we're looking at the rise, fall and return of a truly fascinating game design philosophy. You can't talk about immersive sims without first talking about 1992's Ultima Underworld: The Stygian Abyss. A.k.a the most influential game you've never played. Its 3D engine prompted John Carmack to write a better one and make Wolfenstein 3D, and putting an RPG into that 3D world inspired Bethesda to do the same with the first Elder Scrolls game.

But Underworld's standout feature was using clever systems, artificial intelligence, and even rudimentary physics to try and simulate a believable space that wasn't completely predetermined by the developer. The overarching design goal was to give players unique stories, and then let them come up with personal solutions to quests, much like in a Dungeons and Dragons campaign. Only, replace the human dungeon master with a complex nest of intertwining systems.

The game's developer, Looking Glass Studios, would explore this idea of simulated spaces and player agency in all of its major games. System Shock took Ultima into outer space, and killed off all the humans to avoid those immersion-breaking conversations. Thief used advanced artificial intelligence and open-plan design to forge one of the first proper stealth games. And at Ion Storm Austin, ex-Looking Glass staffers mixed System Shock's shooting with Thief's sneaking for the incredible Deus Ex.

Or Dooz Ex, as you called it in the year 2000. Don't lie. You totally did. So what is an immersive sim? What ties all these games together, and makes them different from the other first person games being made around the same time? Well here are my, personal, tenets of what makes these games special. Immersive sims, for one, offer high levels of agency. Which means you can achieve goals in multiple ways, and pick your own routes, tactics, and gameplay style. The designers tell you what to do - like, break into Lord Bafford's Manor and swipe his sceptre in Thief - but doesn't tell you how to do it.

The designers provide a large open space, perhaps a handful of predetermined routes that support different playstyles, and often some suggestions for how you can finish your mission. But the rest is up to you. To avoid overwhelming the player with choices, your options are sometimes limited by decisions you made earlier. In System Shock 2 you can only carry so many items, and you can only use the powers you've installed and the skills you've developed, so sometimes it's about finding the path that matches the playstyle you're developing, rather than randomly picking new ones for every moment.

Immersive sims are also highly systemic. Most games are heavily scripted. Crazy stuff happens when you stand on invisible triggers, characters play one-off animations at specific bits, and obstacles in the game world just do exactly what they need to do in that moment, and nothing more. Immersive sims, however, are built from systems. So elements have globally defined characteristics which means every alarm post works the same way, every torch can be extinguished, and while different doors might have different properties, they're all based off the same generic door mould.

There are also endless rules that the world follows. Enemies can find you based on sight and sound, and will then run off and trigger an alarm. Footsteps sound louder on tiled floors, turrets shoot who you tell them to shoot, and objects fall when pushed. Remember: physics were still novel back then. For a neat example of scripting versus systems, note how in Thief: The Dark Project, you can attach rope arrows to any wooden surface. Whereas In Thief 2014, which dropped a lot of the emergent sim stuff you can only plunge your grapple into beams marked with white rope.

The less prescripted stuff means that immersive sims can be emergent. When two systems talk to each other, interesting new behaviours can emerge. These interlinking systems give the player opportunities to come up with smart, intentional strategies that exploit the game's rules. Put a gas grenade on an alarm and then let yourself be spotted, to create a nasty trap. Coax this self-detonating enemy near a fragile door, and then kill it, to open a passageway.

Emergent gameplay can also lead to a mad chain reaction that you could not possibly predict, and puzzle solutions that the developer simply didn't foresee. Like using LAM mines - which the player can safely stand on - as an endless ladder to clamber up walls. Immersive sims are consistent. They try to avoid special cases and one-offs, and there are rarely any failure states for anything other than getting killed. You won't find these games telling you to return to the mission area, or making you restart the level because an ally was killed in duty. The simulation just continues.

There are limits, though. You can shoot any character you like in Deus Ex, but you can't just kill plot-relevant characters... until you're actually allowed to. And at that point, you'll find that immersive sims are reactive. The plot doesn't have to drastically change to reflect your choices, but characters will act in different ways and say different things to reflect on your decisions. Even if you thought no one would notice...

MANDERLEY: By the way, Denton, stay out of the ladies restroom. The games judge your actions during gameplay, not in clearly designated choice sections. Clint Hocking, who was inspired by immersive sims with Far Cry 2, has said "by creating a chain of influence that cascaded between the narrative and the WASD keys, Deus Ex allowed players to experience the repercussions of their immediate input level actions as they echoed upward into the very plot of the game".

So these are the tools that Looking Glass and Ion Storm used to make games that felt immersive. Not with photorealistic graphics or by getting rid of the HUD, but by letting go of the player's hand. Deus Ex, for example, was "designed, from the start, as a game about player expression, not about how clever we were as designers, programmers, artists, or storytellers" says director Warren Spector. "The game was conceived with the idea that we'd accept players as our collaborators, that we'd put power back in their hands, ask them to make choices, and let them deal with the consequences of those choices".

To those of us who played them, immersive sims felt like the future. They let us do what we wanted, they reacted to our decisions, and they operated in spaces that acted more like a simulation of a real place than a phoney video game rollercoaster ride. But there were, after all, only a few of us. Deus Ex sold like 500,000 copies while Half Life - equally brilliant, but for a very different reason - shifted millions.

Deus Ex was a cult classic, not a landmark title that would start a revolution. Immersive sims muddled along with the forgettable Deus Ex sequel Invisible War, the contentious third Thief game Deadly Shadows, and the more well received spiritual successor to Underworld, Arx Fatalis. But the closure of Looking Glass in 2000 and Ion Storm Austin in 2005, and the booming blockbuster success of more linear and scripted games, meant the design ethos kinda went away.

It bubbled up here and there, mostly thanks to new Elder Scrolls and Fallout games, as well as BioShock from System Shock 2 designer Ken Levine, and Eastern European efforts like Pathologic out of Russia and STALKER out of Ukraine. But now, the genre seems to be making a triumphant return as games and names and ideas from Looking Glass and Ion Storm history have returned. The new Deus Ex games are made by all new people but are pretty faithful to the original game, other than the crappy inconsistent boss characters (who were mercifully changed in the director's cut edition), and slightly less scope for emergent gameplay. You'll get plenty of that in Dishonored, though, which comes from Deus Ex lead designer Harvey Smith.

This stealth games lets you juggle loads of magic powers, and lots of interweaving systems, to come up with unique ways to assassinate your targets. It's also highly reactive to your playstyle, with rats becoming more plentiful if you choose to murder loads of guards. And then there are all the upcoming games I mentioned in the opener, which should be very interesting. "While I've seen some efforts, especially from the guys at Arkane, to sort of extend the design philosophy of Looking Glass - I'd like to go further with that," says Spector. "It's nice to see more people trying, but I think there's a ways we could go as well, in terms of empowering players to tell their own stories. Those are the directions I'm going to try to go in".

What I'm most excited by, is the opportunity to update this old philosophy with the tech and design of today. Immersive sims really take advantage of, well, sims. Simulations. And games are now much better at simulating crowds, artificial intelligence, fire, weather, and physics. This genre can also learn from other types of games, and borrow stuff like stories that dramatically react to your actions like in Shadow of Mordor. And yes, they can also benefit from the photorealistic stuff to make these worlds even more believable.

And going forward, there's VR: perhaps immersive sims are the perfect match for virtual reality. Indeed, even in the earliest days of Looking Glass, the studio thought about future technology. Major contributor Marc LeBlanc said "everyone was hearing about how virtual reality was coming and most people thought that virtual reality was a hardware thing. We were kinda coming at it from the software thing: if there's going to be a virtual reality that you're interacting with then it's gonna have to have rules and a simulation and stuff like that".

But, ultimately, this a design ethos that just needs to be explored further. Immersive sims, with their system-driven worlds and consistent behaviour - are never going to be as flashy (or as profitable) as crazy, scripted, rollercoaster rides. But sims like Fallout and Deus Ex, and games with similar design goals like Metal Gear Solid V and Hitman, do something truly unique. "Simulations allow players to explore not just a space but a 'possibility space'," says Warren Spector. "They can make their own fun, tell their own stories, solve problems the way they want, and see the consequences of their choices. That's the thing that games can do that no other medium in human history has been able to do".

Thank you so much for watching. If you are wondering where Boss Keys is, the episode on Majora's Mask is up next. As for Game Maker's Toolkit it is funded entirely by people on Patreon, who are amazing and I want to thank them all right now. But I'm going to give a special, on screen shoutout to everyone who donates $5 or more.