Building Hitman games requires everything from paper and tape to patience and lots of iteration. In this article, Io-Interactive’s Principal Level Designers Jacob Mikkelsen and Lee Varley give a rare insight into the process behind the creation of game levels.

Building levels for a Hitman game is not a conventional task. Jacob Mikkelsen explains this to me while I’m seated with him and fellow level designer Lee Varley in a small meeting room at Io-Interactive. »A lot of other games will feature you as the good guy starting in some location«, he begins »and then there’s basically a ton of bad guys coming at you and they’re all trying to kill you. That’s not really Hitman. At least, it’s not the initial state of a Hitman level. In our games, we try to create some kind of space, a public space, where everyone can go and do their thing and that’s where we start you off. And then there are several layers of systems in place that will stop you from just progressing beyond that initial point. When you start poking at these security elements, that’s when things escalate and become both dangerous and interesting.«

And interesting they are. Hitman games have had an iconic presence in the games industry for 15 years, from the debut of Codename 47 in 2000 to the release of Hitman: Absolution in 2012 and the upcoming Hitman in 2016. Each iteration of the game has added to the complexity of what players can do in the game and with that, building levels has become an increasingly more elaborate task involving lots of time and a large group of people from a wide range of game development disciplines.

The beginning

»To begin with,« says Lee Varley, a veteran of level design at Io-Interactive, »we form a group of senior designers called track owners and they are called the level directors. They will sit down with the game’s direction team and the writer and hammer out basics and give birth to the level.« Varley explains that everything from targets and location to various requirements such as fantasy elements, the types of gameplay wanted and anything specific the team wants the player to experience – these are called out on day one.

The fantasy of embodying a professional assassin who, at his best, leaves no trace of his presence in a level and only leaves the target dead, is what drives those early meetings. Says Varley: »Early on, there’s a lot of conversation about the fantasy of how Agent 47 would handle something like an accident kill using the giant light rig hovering above a catwalk at a fashion show, for instance. We need to have the target on the stage, we need to have some gameplay that makes him do that based on the player’s actions.«

The thing is, in a Hitman game, the player’s actions are what should shape the actions of the NPCs. They will live on their own and have their own routines and purposes in the game world but if the player wants them to deviate from the plan, he or she will need to push the AI in the direction wanted. This is the core of the Hitman experience – player freedom and the promise that he or she can manipulate the AI and the environments to reach the achieved results. This means that level setups need to be clever and allow for a lot of things. This is also, in part, something the gameplay group will take care of, Jacob Mikkelsen explains: »We make contracts with the gameplay guys as early as possible to ensure that we don’t need to drastically alter setups halfway through the process.« But in the early phases, planning is everything because the player freedom allows the player to affect every aspect of the game world through their actions.

»We need to take care of all of these outcomes and figure out how the fashion show will react to all the various kinds of things the player will do to it«, Varley explains. »What happens if Novikov (the target at the fashion show) disappears, what if the chief designer is suddenly missing? Or what if you’re on the stage or the light rig goes down before Novikov is there?« There are lots and lots of factors like these that go into the design and need to be figured out in terms of how they are handled. So before anything is built – even mockups – there’s a big chunk of work that happens first. That work can be on paper, on white boards, or in meetings. Mikkelsen explains further: »Some people, like me, use paper and scissors and tape – the Paris levels where the fashion show takes place is an example of that. Everything was built using paper to begin with and that’s a way for the level designer to iterate on the physical shape of the building without changing anything in a 3D modelling tool or any other tool that might be used. It’s a challenge with staircases and how you connect but using layers of paper makes it easier.«

Mapping the target routine

From there, the team figures out what the target is actually doing in the level. What story moments does the level need? »The writer often has a number of key moments that helps the player get to know the target a lot better«, Mikkelsen explains, »although it’s not always certain the player will actually experience those moments because he’s free to do what he wants.« And then the focus turns to making sure that when the player follows the target around, he’s always going somewhere new or presenting a new thing about himself. »We always want the player to learn something«, says Varley. »Maybe it’s a different way of taking the target out or a key bit of information that will let you get close to the target or open up a new approach through the level.«

Figuring out how to present the target in potential kill situations is challenging but also fun. »During play testing, we learned that the second the target is alone, he’s going to die«, Jacob Mikkelsen explains. »In an early iteration of the Paris level in Hitman, there was a lonely and dark logistics area in the back where Novikov would go outside the venue. Everybody would just kill him there. If there’s an easy way to get to the target just by observing him that’s a flaw in the design and we spend a lot of this early time trying to weed out those moments.«

Once there’s a solid idea in place in terms of what the target, or targets, are doing in the level, it’s a matter of understanding how to put in restraints and challenges. Hitman games rely a lot on the idea of social stealth – that you will be hiding in plain sight, infiltrating areas in disguise and generally use your knowledge of the level’s layout and the routines of all its NPCs to manipulate events, ending of course with the death of your target. To ensure a level lives up to those design ideas, the early process also involves getting a good idea of how the level’s trespassing zones are configured. Trespass zones mark the boundaries between different sections of the level – the bar vs. the backstage area, for instance – and depending on what disguise you’re wearing, you’re either allowed in one area or not. Some zones are public; others require you to wear specific disguises to fit in without being accosted.

»At this point in time, the map is starting to take shape on a conceptual level. The design is starting to take shape as well – the basics of who is allowed where and why is beginning to come together. Story is also starting to take shape and sit above it and tells the relationships between the different characters. What we call the target loop for the player, what he’s basically going to be doing to achieve his goals also gets handled at this stage«, Varley explains.

The first digital building blocks

From that initial paper-based understanding of the level’s layout, the target routines, the different trespass zones, the story hooks and the wide range of options available to the player, the level moves into block-up, where things are built. This is the first time the level design team gets a feeling for just how big the location actually is.

»To begin with, this is just using basic geometry«, Varley tells me. »Sometimes it’s just you building things, sometimes it’s you and an artist.« The idea is to relatively quickly transfer the ideas and initial concepts to a playable state, so while it’s being mocked up, the level designer populates the environment with NPCs. »In the early process we just borrow characters from other levels because the real ones obviously don’t exist yet«, Mikkelsen says. »And from then on the level is kind of alive and becomes playable pretty quickly.«

After that point, when the level starts to assume a semblance of life, a million details need to be added in, Mikkelsen explains: »Then it’s about playing with LEGOs. You need to figure out what the people in there are doing. Maybe they are at work, maybe they are guests at the fashion show? We look at how we can make them come alive. That’s what we spend a lot of time on.« But at the same time, the game design needs to be weaved into the level – two civilians having a conversation in a public place is potentially a blocker for the player because he wants to be stealthy. The player could always kill the civilians but Io-Interactive most often sees that people want to play in a certain style. They have an idea that Agent 47 is a professional and doesn’t need to kill everyone. So just two civilians standing in a doorway could be a blocker for the player.

Luckily, the gameplay team has provided the player with a lot of tools. He can throw things to distract the civilians, he could pull the fire alarm or he could sneak through a window beside them to get around like that – so all of a sudden a simple moment of two people talking together in a doorway becomes a key gameplay element. This means that a lot of time is spent on placing out these moments in the world while making sure the player can actually read the situations because that’s the next problem. As Mikkelsen says: »Often in the first iteration, it’s hard to communicate to the player what good options he or she has available right now. So from a level design perspective, it’s about having covers that silently guide you and it’s about having light that subtly show you where to potentially go.«

Explore, attack

One of the tricks that the level designers at Io-Interactive use is to make sure that the player relatively quickly gets a sense of who the important people in a given level are. This is done through a combination of lighting tricks and character movement – the important characters will move around in the level, while the lesser important ones tend to stand still. This draws the player’s attention, which is good because over the years, the levels have grown in complexity and size and because of how a Hitman game works, the design team has no real control over where the player is at any given time.

Lee Varley pitches in: »In Paris, you have a reasonably large area to begin inside and that’s a sort of free space – you can move without being accosted there because you’ve got permission to be there, you’re a guest. But if you want to go anywhere, you need to break the rules pretty quickly. And that will give you the option to get a sense of who the important people are, who the target is and a few opportunities present themselves while you’re still relatively safe.« He explains that one of the core game loops in the Io-Interactive level design approach for Hitman games is »explore, attack, explore, attack«.

For the exploration, the player needs space to be able to roam and look at options in order for them to form a plan of attack. They’ll attack the level, get past whatever road block the designers put up and following that, they’ll get to explore a bit more to figure out what’s next. Once they’ve gone through the loop a few times, they’ve conquered the level almost in a »moving around« kind of a sense and now they’ll be ready to plan for the attack on the target. So the loop of the game is very much about letting the player have quite a lot of freedom to poke around and to see what they can do. Once they’ve done that, the game presents them with a little puzzle where, if they want to explore more, they will have to »upgrade« themselves – either by becoming someone else or getting past the puzzle in some other way, be it traversal, combat or the use of tools. Eventually, they will have a very good sense of what goes on where, how to get to the different sections of the level without getting caught and from there they are in an excellent place to perform their final attack.

Scoping the levels

When it comes to sizing up the levels, the goal for Hitman levels is that all areas have some sort of relation or purpose to you or your mission. The palace in Paris, for instance, has a garden outside it and presents the player with a low-populated fringe area, which goes all the way around the main building. Stealth takes a lot of space to pull off – low covers give you a lot of visibility but that also applies to the AI. They can overview a lot of space at once if there are no obstacles set up.

»So, it’s a combination of how much space do we want to give you to overview things and infiltrate«, says Mikkelsen. »Because two AI characters can easily cover a large area. It’s about identifying the necessity of each area and then sometimes we end up having dead space here and there – but on the other hand, when things go wrong for you and you run to one of these empty areas and there’s a closet there, then you’re in luck and it’s a lifesaver.« These are the things that are hard to foresee in the early phases of level design and need to come out in playtests. »We do try to design dead space into the game here and there but it’s really difficult to judge size until you’re quite far along and it’s definitely one of our Achilles’ heels in level design.«

Normally Hitman levels start out too big. The team actually prefers it that way because it’s easier to scope a big level whereas something too small is hard to scope, Mikkelsen explains: »When we build a really big room, it’s easy to put more stuff in there to make it feel more condensed but if the room is too small, we’re in a lot of trouble because of the geometry that surrounds it and it’s hard to make it bigger.« Another thing that is really important to the Hitman team is to ensure that every passage leads to some place. Every room is connected to another room – almost like holes in a cheese. Toilets are usually the exception here but even some of these allow you to exit through a window. »When we do the level design, we try to design loops on the map layout«, Mikkelsen says. »So we loop the map as much as possible because we know that if you get into trouble as a player, you can always loop yourself around somewhere.«

Dead ends can be a bit of a problem in a Hitman game. But the price is that it’s easy to get lost when you can always go somewhere. And that where the NPCs need to help you go somewhere relevant – nudging your players in various directions by using the same kind of principals that supermarkets, for instance, use their layouts to make you go certain places and pick certain things. If you put an NPC with his back to the player and place a hammer next to him and do it close to a body dumpster then that constellation will mostly lead to people picking up the hammer, whacking the guy over the head and hiding his body. Hitman has a number of these setups where the game will nudge you into doing these kinds of things.

»And sometimes it’s fun to just play with the player«, Lee Varley continues. »Have a guard on his own and stick a shotgun next to him. You’re kind of encouraging the player to pick up the gun and shoot the guy – but then again, do you want to? It’ll be noisy and messy. It’s good to tease the player – fill the level with interesting choices.« And an important point here is that all the choices don’t have to be about achieving the highest ranking of »Silent Assassin«. Some things are just in there to push you to see what you’ll do as a player – because it’s fun! But it also presents you with the choices in the game and shows you the variation and freedom of approach, which is essential in a game like this.

Failsafe design

Keeping track of everything that goes on in a Hitman game level is a real challenge and the team at Io-Interactive knows very well the kinds of things the players will do to the game in their efforts to break the systems and get those elusive »Silent Assassin« ratings and truly creative kills. »People are doing a lot of things with our games and it’s something we really like«, Mikkelsen explain. »They will try to sabotage it in a hundred different ways, fraps their efforts and put them online. Everything from speed runs to making the game behave in various ways. Most of what you see out there like the target getting run over by his own bodyguards, that’s not something anyone here has designed. It’s something that happens because there’s a rule that says ›if you get hit by the car, you die‹ and someone figured out how to take advantage of that. And that’s where were we’d like to end up with every level we set up – with emergent behavior that we didn’t foresee.«

Still, in means that creating meaningful experiences in Hitman games is a lot like trying to contain a hurricane inside a small glass bubble – it can get pretty chaotic very quickly. Mikkelsen goes on to explain:

»Luckily, as level designers, we’re saved by a lot of things. Once the NPCs become alerted, the level designers kind of lose control and the AI takes over. So what we have to do when we build these moments with all these characters is to follow this one rule – you should always assume that any character can disappear at any time without anyone noticing it. That’s kind of the worst case scenario.« Imagine that Agent 47 snatches a random character in a level and nobody sees it, even if another NPC is standing right next to the action. That could break a lot of things in a conventional game. If you have two characters meeting and then moving on after that, you need to make sure one of them doesn’t get stuck if his conversation partner never shows up, for instance. The level designers always have to make sure that they know what will happen if the thing they DID want to happen DOESN’T happen.

For this reason, the Io-Interactive level designers build a lot of failsafe mechanics into the design. And those failsafe mechanics are systemic, meaning they’re based on scripted events. Instead of scripting all potential outcomes, the reverse is done – a failsafe is created and then a number of potential moments that can happen are crafted. If they don’t happen, the characters go back to the failsafe routine. »I try not to think about it, I just do it«, Lee Varley says, »because as a level designer there’s also an amount of … you have to let go a little bit because the level’s complexity will have, around the time of alpha, grown so much that you can’t dictate what goes on on the map anymore and you kind of need to encourage it to happen.« A level is designed, built and the gameplay is layered on in the various systems that are available. And then comes a point where it kind of becomes alive. And then it’s a question of trying to make it go in the right direction. »Because you kind of lose control of everything and that’s what we want«, says Mikkelsen. »The bigger the maps, the more complex they are and grow, which means more emergent behavior and that’s something we definitely want. We embrace this – it’s Hitman.”

Jacob Mikkelsen, Lee Varley, Nick Price