Level design lessons learned building Deus Ex: Mankind Divided's Prague

Sylvain Douce has spent the last six years of his life working on Deus Ex games at Eidos Montreal, and at GDC today he shared some of what he’d learned as a senior level designer on last year’s Deus Ex: Mankind Divided.

If you’re familiar with the game, you’re familiar with its vision of Prague -- a multi-layered warren of streets, alleys, sewers, and remarkably clean, human-sized air ducts.

Prague was built, says Douce, to accommodate what he describes as Mankind Divided’s two primary pillars: stealth and confrontation. The development team established a series of player archetypes by analyzing what players like to do most (the “killer” archetype is motivated to quickly progress by using force, for example) and designed the level to make sure there were lanes for each type of player.

To accommodate the fast lane of progression (for “killer” player), the team made sure all sub-locations are equal distance from each other and spread fast travel stations (as metro stations) throughout the city. This simple philosophy of design was shrunk down and applied to Prague’s smaller zones, like the sewer network or the multi-floored Palisade bank building.

Knowing that players would spend a lot of time in the city navigating it in accordance with their interests, Douce says the team also took pains to fill it with easily-recognizable assets. These monuments were also spread out strategically in the city, placed in areas where they could be very clearly seen when players exited buildings or metro stations in order to quickly help them orient themselves.

“In order to provide a clear path, we used well-known landmarks,” said Douce.”We made the most out of them, and took special care in designing them. We have strong art direction, and we wanted those monuments to stand out and define the city.”

And for players with “explorer” motives who might want to spend a lot of time exploring the city, Douce says the team worked to create “deep pockets of exploration” -- special areas that were optional but rewarded players that found them with items and bits of narrative.

Codifying the "types" of people who will play your game can help you design a more fleshed-out world

Thinking of players in terms of archetypes can be a big help in approaching game design, says Douce, because it gives devs an easy way to contextualize the challenge of building multi-layered zones.

So for example, if “killer” players drive devs to build mainline content, Douce believes catering to the “explorer” player archetypes drives production of side content. For Mankind Divided, Douce says the team studded side missions throughout Prague off the “critical” path so that they wouldn’t interfere with players who wanted to quickly push through the game, but would reward players who wanted to explore and discover things.

However, Douce then said the team would also sometimes put side quests in the way of the game’s “critical path” to make sure players would at least be aware that side quests exist in the game. As an example, Douce pointed to the “Golden Ticket” side quest -- one that is initiated when the player tries to cross a checkpoint on the way to a main quest objective, but is blocked by what seems like a corrupt cop. This side quest is optional -- the player can sneak around the cop -- but Douce says it was important to the dev team to put it there so that players would be aware that there was more to Prague than the main quest.

For players who want to chat up NPCs and explore meaningful relationships (the “socializer” archetype), Douce says the team tried to fill Prague with interesting characters and merchants to chat with. The designers view this kind of player as the driving reason to fill the game with interesting side conversations, events, and people -- what Douce describes as the LBW, or “living, breathing world.”

It was for these players that the team also tried to build interesting debates for the game’s debate minigame, which occasionally crops up during conversations with select NPCs.

For the “achiever” player archetype, which Douce vaguely defines as the people who play to “do what you can’t”, the Mankind Divided team tried to design parts of Prague that reward player creativity -- say, by creating parts of the city that are incredibly tricky to get to.

“We could see players starting to stack up and create pyramids of physical objects,” said Douce. “They were creating ladders to places that were unreachable otherwise,” so the Mankind Divided team left some surprises in such areas to reward players who chose to go to the trouble of getting there.

"Choices are all about feedback"

“Choices are all about feedback,” said Douce “If you provide choices but never acknowledge their existence, players will notice and they will shut down your game.”

To provide feedback on player choices on something like how to approach a mission (stealth vs. confrontation, for example), he says the Mankind Divided development team established vectors for providing feedback: things like in-game newspaper headlines, for example, or email which will be sent to a player when they repeatedly break into their police HQ.

“But we know all those readables don’t really click with all players,” said Douce. “So we also have briefers,” NPCs who will respond to player actions by either direct communications (a voice in the player’s ear shouting “I can’t believe you did that!”) or conversations amongst themselves.

Obviously, writing emails is cheaper from a production standpoint than recording dialog for an NPC response; beyond that, the city itself could be customized to respond to player actions. Douce says it was expensive -- the city is seen in three different states (day, night, curfew), so building out dynamic responses to things like the death of a shopkeeper (first the shop is closed off with police tape and has a police officer spawned out front, then later the police presence is removed but the shop is permanently closed) was painfully expensive. 

Another thing that quickly got pricey was trying to build branching paths for the game's quests.

“The first thing we tried is branching...we used it a lot in Human Revolution,” said Douce. “But as you know, it gets quickly expensive...so we tried to go beyond branching."

However, he cautions that the team had several prerequisites: “We want scalability, for instance.” So what if players could dip in and out of a side quest at different times, for example, or have a side quest last much longer throughout the main story if the player made certain choices?

The problem, says Douce, is that each side quest required a full-time designer and a full-time writer. “We needed to find a new approach,” he said, because it just became too expensive to try and do a lot of branching quests.

Instead, the team came up with the “bracket technique” -- it’s a five out of ten on Douce’s “own internal cheap-o-meter” and basically sets up a quest so that it has a simple straightforward arc with a lengthier middle chunk as an optional “bracket” which can be brought in based on how a player tackles the quest.

“But of course, it’s a matter of resources and how you manage the balance,” said Douce. .”Of course you want to spend most of it on the critical path, where most players will see it. So you have to be smart elsewhere, and use cheap tricks for the one percent [of players.]”

For fellow devs, Douce advises that you work tightly with quality assurance experts as you work out how to design paths and quests in your game. He also admits that trying to pack a zone with lots of different paths and feedback vectors caused significant production headaches because of the impact on performance.

As an example, he shared how he Mankind Divided team eventually had to make the “very hard decision” to split Prague in two (it was originally meant to be one zone.) However, Douce says once that was done it was possible to knit the city together via the aforementioned fast travel hubs and ship it -- albeit with some hacked-in workarounds.

“The sad conclusion to that story is we simply shipped as-is,” said Douce. “All of us built this mental database of careful workarounds, and that allowed us to eventually ship the game.”

In closing, Douce offered the following bits of quick advice to fellow devs looking to build believable virtual worlds that respond to player actions: