Hitman

Most players never reach the end of a Hitman game. IO Interactive said only 20 percent of players would reach the last level of Hitman: Absolution.

It is cited as an example of why publishers fear paying for content most players never see.

Make critical alerts prominent with colour, motion and sound. The trespassing alert was a plain label under the mini-map in Hitman 2016, became yellow and flashing in Hitman 2, and gained a clear sound cue in Hitman 3.

Reward stealth with scores instead of failing players for being seen. A high score and challenges like Silent Assassin require never being seen, hiding bodies and deleting camera recordings.

Challenges stay optional, giving structure to players who want it while others ignore them and make their own fun.

Layer disguises as security tiers and hold the best one back. In Kronstadt anyone can enter the lobby, an IT uniform opens the second floor and a guard uniform opens the top floor. Designers place the strongest disguise late.

The team first maps who works in a place, then layers access; the hotel needs a Knox elite guard outfit and each paddock needs team colours. "If the first disguises you meet is the best one then we're wasting a lot of gameplay for no reason."

Use public and private zones as readable rules of behaviour. IO's Mette Andersen explains that public spaces are open in any costume, while private spaces need ingenuity and a costume. The best levels mix these area types richly.

Players use real-world social knowledge to guess where they can go. Enforcers see through disguises, so private areas keep some danger even in the right outfit.

Scatter small stealth puzzles across the level instead of gating doors. Hitman: Absolution was linear, with guards in front of a door. In Miami, an engineer in Moses Lee's pit building and a doctor in the medical area can each be distracted with a nearby generator.

The world itself can provide distractions, such as overflowing a sink to pull a guard off patrol.

Limit and counter tools so no tactic becomes the default. A cupboard holds only two bodies, and enforcers see through disguises.

Wind one obvious path through a small space, then punch shortcuts through it. Miami is a winding 'snail house' that packs a credible race track and hundreds of NPCs into a small, console-friendly footprint. 'Swiss cheese' holes like fences, windows and elevator shafts let veterans almost teleport.

The model is IKEA: a guided path through showrooms plus staff shortcuts. Signs, floor lines and in-world maps guide novices to landmarks while shortcuts stay secret. IO aims for credible spaces, not perfectly logical ones with every bedroom and kitchen hundreds of people would need.

Use public and private zones as readable rules of behaviour. IO's Mette Andersen explains that public spaces are open in any costume, while private spaces need ingenuity and a costume. The best levels mix these area types richly.

Players use real-world social knowledge to guess where they can go. Enforcers see through disguises, so private areas keep some danger even in the right outfit.

Fixed target schedules let players build plans they can trust. Targets follow clockwork routines and the world marches on, indifferent to 47, until he pushes against it. Knowing the fashion show ends with Viktor Novikov on stage means a plan built for that moment will work.

Levels are made of many small loops, with characters repeating schedules every five to ten minutes rather than resetting the whole level. Jakob Mikkelsen, game director on Hitman 2: "If you know, as the player, that something will happen, then you can build a plan on that knowledge."

Start a level from a fresh location idea, like the race's offstage areas. IO brainstorms settings with a 'wouldn't it be cool if' question. Racing games always keep you on the track, so Miami's Global Innovation Race lets 47 explore everything except the track.

Other brainstormed settings included a fashion show and the slums of Mumbai. Location, targets and dramatic moments form the 'high concept design', and the level design comes after.

Fixed target schedules let players build plans they can trust. Targets follow clockwork routines and the world marches on, indifferent to 47, until he pushes against it. Knowing the fashion show ends with Viktor Novikov on stage means a plan built for that moment will work.

Levels are made of many small loops, with characters repeating schedules every five to ten minutes rather than resetting the whole level. Jakob Mikkelsen, game director on Hitman 2: "If you know, as the player, that something will happen, then you can build a plan on that knowledge."

Mix target types, dwellers and roamers, so each hunt poses different problems. Robert Knox is a 'dweller' who loops through his Android lab, balcony and secure office fortress. Sierra Knox drives the track for nearly 20 minutes, then becomes a 'roamer' in the VIP area.

Off the track Sierra can be killed as a Flamingo mascot, with a poisoned IV drip or during a drinking game; on it, she can be shot on the straight or her car rigged in the Kronstadt pit building.

Ask what could go wrong for each target, then let the player cause it. Breaking Knox's air conditioning sends him to use eyedrops you may have poisoned; switching off the satellite or breaking his prized car pulls him out to fix it.

Each disruption needs setup such as poison, an octane booster, a secure room or a disguise. The design question: "what could possibly go wrong here, and how can Agent 47 get a grip on the situation?"

Seed small teases so players spot extra kills themselves. A facial-recognition military robot makes you hunt for a photo of Knox; an overheard race official warns the podium pyrotechnics could fry everyone; the trophy champagne can be poisoned.

Eskil Mohl compares these to a cannon with gunpowder nearby: "it's constantly giving you little promises." Overheard dialogue and the challenge list also hint at kills, and the challenge list can be turned off.

Make the player work to create the kill opportunity. By default Sierra finishes second and never reaches the podium, so the player must help her win or make Moses Lee lose to use the podium kills.

IO went back and forth before choosing this. Mikkelsen: "Making it so that you can make the decision whether she wins or not - it puts you in power." Mohl adds that the team likes to taunt targets, which Mikkelsen calls poetic justice.

Turn waiting on schedules into something the player can shortcut. Sierra drives for nearly 20 minutes, so players can disqualify Moses Lee to end the race and bring Sierra to the stage, or disqualify Sierra to bring Moses.

IO also has some characters run and offers a starting position with the race nearly over. Mikkelsen: "instead of trying to make it a thing that you have to wait for, or a limitation, then we try to turn it around."

Wind one obvious path through a small space, then punch shortcuts through it. Miami is a winding 'snail house' that packs a credible race track and hundreds of NPCs into a small, console-friendly footprint. 'Swiss cheese' holes like fences, windows and elevator shafts let veterans almost teleport.

The model is IKEA: a guided path through showrooms plus staff shortcuts. Signs, floor lines and in-world maps guide novices to landmarks while shortcuts stay secret. IO aims for credible spaces, not perfectly logical ones with every bedroom and kitchen hundreds of people would need.

Give most rooms two exits so players never feel scripted. The Kronstadt building can be entered by the front door, parking lot, podium building or a walkway door. Toilets are the usual dead ends.

Other challenges may block a room, but the player never has to turn back, so they feel they choose their own route. This open, multi-route structure is shared with Thief and Dishonored.

Spread crossings along any barrier that splits the level. The race track cuts Miami in two, so designers added two overhead walkways and several subway passages linking to an underground parking garage.

Robert's side holds the stands, food trucks, VIP bars, paddocks, medical tent and motel; Sierra's side holds the Kronstadt building, podium building and marina.

Layer disguises as security tiers and hold the best one back. In Kronstadt anyone can enter the lobby, an IT uniform opens the second floor and a guard uniform opens the top floor. Designers place the strongest disguise late.

The team first maps who works in a place, then layers access; the hotel needs a Knox elite guard outfit and each paddock needs team colours. "If the first disguises you meet is the best one then we're wasting a lot of gameplay for no reason."

Scatter small stealth puzzles across the level instead of gating doors. Hitman: Absolution was linear, with guards in front of a door. In Miami, an engineer in Moses Lee's pit building and a doctor in the medical area can each be distracted with a nearby generator.

The world itself can provide distractions, such as overflowing a sink to pull a guard off patrol.

Replay the level constantly and fix moments that are too easy. A Paris section in Hitman 2016 was changed because Viktor Novikov was alone too long and became an easy kill.

"The more times we can actually boot up and start the level before we ship it, typically the better it gets."

Tune challenge modes around luring targets, not waiting for them. For Sniper Assassin, IO hides sight lines so the challenge is luring a target into position. Suit Only needs little tuning because players always find a way.

Treat design rules as guidelines and plan levels as a chain. Levels vary in verticality, crowd density and size, and each contrasts with its neighbours: dark, claustrophobic Night Call precedes Miami, and San Fortuna's huge fortress follows it.

"I'm personally very opposed to rules dictating how things should be, because then everything's going to be the same."

Give most rooms two exits so players never feel scripted. The Kronstadt building can be entered by the front door, parking lot, podium building or a walkway door. Toilets are the usual dead ends.

Other challenges may block a room, but the player never has to turn back, so they feel they choose their own route. This open, multi-route structure is shared with Thief and Dishonored.

Let players earn the assassin fantasy the trailer promises. The trailer shows a flawless Agent 47, but first attempts are clumsy; the fantasy arrives only after learning the level and mastering stealth.

Hitman's levels work as a choreographed system in which the player is the spanner in the works.

Subtitle background lines that carry gameplay information. Hitman uses short stabs of dialogue over a couple of lines, but guard lines saying whether your disguise lets you into an area have no subtitles.

Make 47 weak in firefights so players avoid the easy route. Hitman kills you in a few shots, pushing you into the shadows and toward inventive plans instead of a reliable brute-force solution.

The contrast is Just Cause 3, where you absorb dozens of bullets, and Metal Gear Solid V, where Mark Brown finished many missions by abusing the silenced tranquilliser gun.

Let players earn the assassin fantasy the trailer promises. The trailer shows a flawless Agent 47, but first attempts are clumsy; the fantasy arrives only after learning the level and mastering stealth.

Hitman's levels work as a choreographed system in which the player is the spanner in the works.

Reward stealth with scores instead of failing players for being seen. A high score and challenges like Silent Assassin require never being seen, hiding bodies and deleting camera recordings.

Challenges stay optional, giving structure to players who want it while others ignore them and make their own fun.

Endless replays and saves drain tension from mastered levels. Hitman encourages replaying missions until you can pull off the perfect hit, but once a level plays like a choreographed dance you stop adapting, and a mistake costs only a restart or reload.

Elusive Targets restore stakes with one attempt and unknown schedules. Each target appears for only a couple of days, about every couple of weeks, in a level you already know, with extra guards and unknown schedules. Once you engage, there is no second chance.

Regular missions become training for the real hit. Lead online designer Torben Ellert calls it "the purest possible experience of being the assassin." You can still restart before engaging.

Use limited-time events to offer play the base game cannot. Where others run double XP weekends and Halloween skins just to bring players back, Hitman uses the disposable nature of Elusive Targets to create a different style of play.

Make 47 weak in firefights so players avoid the easy route. Hitman kills you in a few shots, pushing you into the shadows and toward inventive plans instead of a reliable brute-force solution.

The contrast is Just Cause 3, where you absorb dozens of bullets, and Metal Gear Solid V, where Mark Brown finished many missions by abusing the silenced tranquilliser gun.