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Game development








Hello! I'm Tom. I designed a game called Gunpoint, about rewiring things and punching people, and now I'm working on a new one called Heat Signature, about sneaking aboard randomly generated spaceships. Here's some more info on all the games I've worked on, here's the podcast I do, here are the videos I make on YouTube, here are some of the articles I wrote for PC Gamer, and here are two short stories I wrote for the Machine of Death collections.


By me. Uses Adaptive Images by Matt Wilcox.

Heat Signature’s Launch, And First Player Legend

A Leftfield Solution To An XCOM Disaster

Rewarding Creative Play Styles In Hitman

Postcards From Far Cry Primal

Solving XCOM’s Snowball Problem

Kill Zone And Bladestorm

An Idea For More Flexible Indie Game Awards

Teaching Heat Signature’s Ship Generator To Think In Sectors

What Works And Why: Multiple Routes In Deus Ex

Natural Numbers In Game Design

Naming Drugs Honestly In Big Pharma

Writing vs Programming

Let Me Show You How To Make A Game

New Heat Signature Video: Galaxies, Suction And Wrench-Throwing

What Works And Why: Nonlinear Storytelling In Her Story

My Idea For An ‘Unconventional Weapon’ Game

From Gunpoint To Heat Signature: A Narrative Journey

The Cost Of Simplifying Conversations In Videogames

What Works And Why: Invisible Inc

Our Super Game Jam Episode Is Out

What Works And Why: Sauron’s Army

Showing Heat Signature At Fantastic Arcade And EGX

What I’m Working On And What I’ve Done

The Formula For An Episode Of Murder, She Wrote

Heat Signature Needs An Artist And A Composer

Improving Heat Signature’s Randomly Generated Ships, Inside And Out

Gunpoint Patch: New Engine, Steam Workshop, And More

Distance: A Visual Short Story For The Space Cowboy Game Jam

Raising An Army Of Flying Dogs In The Magic Circle

Floating Point Is Out! And Free! On Steam! Watch A Trailer!

Drawing With Gravity In Floating Point

What’s Your Fault?

The Randomised Tactical Elegance Of Hoplite

Here I Am Being Interviewed By Steve Gaynor For Tone Control

Heat Signature: A Game About Sneaking Aboard Randomly Generated Spaceships

The Grappling Hook Game, Dev Log 6: The Accomplice

A Story Of Heroism In Alien Swarm

One Desperate Battle In FTL

To Hell And Back In Spelunky

Games Vs Story 2

Gunpoint Development Breakdown

Five Things I Learned About Game Criticism In Nine Years At PC Gamer

My Short Story For The Second Machine Of Death Collection

Not Being An Asshole In An Argument

Playing Skyrim With Nothing But Illusion

How Mainstream Games Butchered Themselves, And Why It’s My Fault

A Short Script For An Animated 60s Heist Movie

The Magical Logic Of Dark Messiah’s Boot

Arguing On The Internet

Shopstorm, A Spelunky Story

Why Are Stealth Games Cool?

E3’s Violence Overload, Versus Gaming’s Usual Violence Overload

The Suspicious Developments manifesto

GDC Talk: How To Explain Your Game To An Asshole

Listening To Your Sound Effects For Gunpoint

Understanding Your Brain

What Makes Games Good

A Story Of Plane Seats And Class

Deckard: Blade Runner, Moron

Avoiding Suspicion At The US Embassy

An Idea For A Better Open World Game

A Different Way To Level Up

How I Would Have Ended BioShock

My Script For A Team Fortress 2 Short About The Spy

Team Fortress 2 Unlockable Weapon Ideas

Don’t Make Me Play Football Manager

EVE’s Assassins And The Kill That Shocked A Galaxy

My Galactic Civilizations 2 War Diary

I Played Through Episode Two Holding A Goddamn Gnome

My Short Story For The Machine Of Death Collection

Blood Money And Sex

A Woman’s Life In Search Queries

First Night, Second Life

SWAT 4: The Movie Script

What Works And Why: Multiple Routes In Deus Ex

Deus Ex’s appeal is often boiled down to ‘lots of options’, but obviously that doesn’t quite cover it. Right now I’m looking to redesign the ‘sneaking inside spaceships’ part of Heat Signature, so I need more than a vague line about what’s cool about Deus Ex – I need a practical understanding of specifically why it works, and why similar games don’t. So I’m replaying Deus Ex 1 and 3, to figure out what it is I want to steal. And I think it is options, but it’s not just number. They have to fill a certain set of requirements, and this is my attempt to nail down what those are.

I’ve been mostly playing Human Revolution so far, but I’ll also use some examples for DX1 since there’s so much overlap.

The basic ingredients

DXHR MEthods

The protein flapjack is not technically a Method.

We’re talking about ‘ways to achieve your objective’. The objective itself is not optional, or different depending on your play style. Heat Signature does have an element of that, but it’s not what’s interesting about Deus Ex – most of the time, especially in 1 and 3, you have no say in what your objective is. The interesting part is in how you get to it. That generally breaks down into:

Routes: the various paths you can take. Some are easily visible, some might be hidden.

Obstacles: any elements that need to be overcome or avoided on a route – enemies, high walls, locked doors, toxic gas.

Methods: anything that lets you get past an obstacle, including basic skills like sneaking, conventional means like guns, environmental things like a switch, and specialised tools like a hacking upgrade.

Routes require different Methods

This is not interesting:

2015-11-06 12.20.46 no obstacles

Multiple routes, but who cares? They’re all the same.

This is more interesting but still pretty trivial:

2015-11-06 12.21.31 enemy

Multiple routes, but one is clearly more trouble than the others, so the choice isn’t interesting.

This is getting Deus Exy:

2015-11-06 12.42.27 three routes

Multiple routes, obstacles on all, and each requires a different Method. Do you have a Method for clearing debris? Do you have a Method for dealing with enemies? Do you have a Method for dealing with locked doors? Which brings us to:

The player chooses which Methods to invest in

DXHR Stacked

I am doing excellent Deus Ex.

This is one area DXHR massively improved over DX1. In Deus Ex 1 a single cheap hacking upgrade got you into every computer in the game, and the aug options were binary choices: A or B, where B is often useless. DXHR makes everything Augs, and both unlocking and upgrading them take the same, painfully rare currency. That gives you enormous power to specialise, and also puts enormous weight on those early decisions. The first few Methods you unlock with this system will be all you have, for a time.

I used to think the virtue of lots of routes was that the player always has a big decision to make as they approach each objective. But replaying the Deus Ex games and really examining the situations I find myself in, that’s not it. Most of the time the choice is already made for me by a previous decision about either the playstyle I want to use or the upgrades I’ve picked. If I’ve got the strength upgrade and I’m playing stealthy, when I see a vent blocked by a drinks machine, I’m moving the drinks machine and getting in the vent. I don’t even need to see the other options.

And that’s OK! The actual deciding process is not the sole pleasure of playing a game. A lot of the fun comes in living out your decision, and seeing it rewarded by Routes that it lets you exploit. You got the strength upgrade? Good choice! Now you get to move this heavy thing and access this special route, which is gonna get you close to your objective with minimal resistance. That makes your playthrough feel personal, it makes your choices feel relevant, and it makes you feel clever.

Methods have different Costs

DXHR Accidenal death

I may have committed a playstyle cost.

If every obstacle was solved for free by some particular Method, and impassable otherwise, that would probably be OK for a while. But pretty soon your choices would either feel irrelevant (if every Method unlocked a Route) or unfair (if your chosen Methods left you with no Route).

Methods need to have different costs, otherwise unlocking new ones wouldn’t be appealing. Basic sneaking is a Method, but it gets harder and more time consuming to use alone as the game progresses. The kinds of costs Methods can have are things like:

  • Resources: blowing up this weak wall uses up a grenade, whereas punching through it with an Aug only takes one rechargable power cell.
  • Risk/Skill: you can use this pistol to take out these three guards, but it’s going to be tricky and you’ll die if it fails. If you have a gas grenade, it’s easy and safe.
  • Time: if you want to get up to that vent, you’re going to need to scrounge around to find another box you can stack on this one. If you had the jump Aug, it’d be quick.
  • Playstyle conflict: yeah, you can probably solve this by just throwing a frag grenade in there. But that’s not who you want to be this time, it’s not how you want to play. You want to do it silently and nonlethally with a tazer and a fridge.
Combat requires a combination of Methods

DXHR Angry hunting

Hey guys! Who are we angrily hunting to the ends of the Earth?

Combat is special. While it’s technically an avoidable obstacle like the others, almost every playstyle and route involves it at some point, and as players we expect it to be ten times richer and more interesting than any other type. We’re a lot less forgiving of a game that only has one type of weapon than a game that only has one type of lockpick.

This is true for me as much as anyone – every one of my favourite Deus Ex anecdotes involves violence either by or against me. In fact, the first moment that sold me on Deus Ex was getting stuck on a bit with two guards – I couldn’t take them both out before one killed me. Then I realised I could round the corner, spray a fire extinguisher at them both, and shoot them while they choke. It felt like I was fighting against unfair odds, improvising a desperate and clever way to overcome them.

In DXHR it’s less about improvisation, but my favourite thing to do is very similar. Lots of situations involve three guards – I like to stand near two of them, shoot the third in the head with the silenced pistol, then immediately hit the takedown key to use my upgraded close combat move on both the others. It feels like a spectacular explosion of violence, too sudden for anyone to stop and yet almost perfectly silent.

So combat needs:

  • The odds stacked against you
  • Multiple Methods
  • Each Method insufficient alone
  • Methods with different strengths

The fire extinguisher can’t hurt anyone, but it can immobilise two people very suddenly without much skill. The pistol can kill in one shot, but only if it’s to the head, and it’s hard to hit a moving head.

If combat tools each have different strengths – range, damage, stun, area, delay – you’re encouraged to come up with some way to combine them to solve the situation at hand, which feels inventive, improvisational and clever.


That’s what I have so far. As with any analysis, it’s not the only way to break it down, and it doesn’t cover everything. I have one more element I want to write up, but I think FTL may be a better example of it, so it feels like a separate post. And if replaying DX1 throws up anything big that this doesn’t cover, that’ll be its own post too.

More ,

A random dude: Yay! It's always a pleasure reading your posts.

J: The strength of Deus Ex level design was always the same strength as Thief's, the simulation-y nature of it where levels were designed as actual places first and then retrofitted to become video game levels. That's where HR fell down I'd say, most of its levels feel like there are specific scripted paths the developers intend the player to go down and anything else is playing the game the wrong way. I'd say the only places HR really had the great level design of the original is in the Police Station, TV Station and the Hubs.

Basically, I think the main appeal of the game's isn't the "multiple routes" so much as the player just being able to do what comes naturally and the game being able to accommodate it. And its always more satisfying to feel like you're doing something the devs didn't necessarily intend you to (even if they actually did account for that edge case) when you're traversing an environment than it is to just find a context sensitive area and run a canned animation because you have the skill that corresponds to it.

Simon Jones: J - I think the key thing there is that in Deus Ex 1, the multiple routes weren't particularly obvious or delineated - at least, not at the start or until you were very familiar with all the systems. And even then, changing location (eg arriving in Hong Kong) would require you to recalibrate your brain. There was a fuzziness to the design which at least made it FEEL like you were improvising, even if the designers fully intended it.

DXHR, which I still love, has much more obvious Methods and routes. The Vent Route. The Front Door Guns Blazing Route. The Conversationy Route. They were generally always really good fun, but about 10 seconds into the level it was VERY clear what all those options were.

J: Simon - While its true that a lot of the possible routes a player could take, even ones that feel unintended, were probably planned out by the designers there are plenty of weird little things in Deus Ex the player can figure out that were almost certainly not intended paths. I doubt every place where one can stack items and then reach what was previously only reachable by going past enemies was intentional, I also doubt the devs considered the possibility a player would take a gep gun at the start of the game just so they could completely do away with the need for lockpicks since they could blow up any door they found, and that's not even getting into clearly unintentional mechanics like LAM climbing or using gas grenades to bypass all of Liberty Island. Its just a game rich with systems layered on systems that the player can exploit to get results never planned for. Boiling it all down to specific routes sticks in my craw because that emphasis on dev prescribed routes instead of presenting a problem for the player to solve was what resulted in most of the stuff I dislike in HR. And I should note, I did like HR, at its best it was just like the first game, but about half the levels in the game were mediocre, just going through the motions the dev planned for you.

Jabberwok: @J - I agree that it's ultimately about the systems in place. And the sandboxy nature of the DX1 levels - giving us two square city blocks in which to hunt down our objective, gather intelligence, and figure out the ways inside. And the routes were often expansive enough that they weren't merely paths. Liberty Island let you approach most of the enemies from any direction you wanted, or skirt around them completely.

But yeah, when Tom mentioned methods, this struck me as the key to it, really. The player has a large toolset, and the environments are reactive in many ways, so one path doesn't mean one method. There are countless ways to deal with most obstacles. Passing through a booby-trapped corridor, I could carefully go through and deactivate the mines, I could detonate them with my pistol or another LAM, I could hack the camera or just destroy it with a sniper round if I've maxed rifle skill, etc.

What works so well is that everything has a set of properties that govern how the rest of the world interacts with it, instead of just being a scripted entity that lets you use one skill on it. So for instance, a weak wall might let you punch through it using your strength aug in a little quicktime event, but a more interesting approach would be a gauge of the wall's strength that lets it be destroyed by anything that can cause that much damage. Suddenly you have many more ways to interact with that one object, and that's what gets my problem solving gears going, and results in a much richer world, overall.

Drew: an aside from a well thought out post, I have to agree with Simon as far as basically obscuring obvious multiple routes. It is maybe the biggest part that makes me go from thinking DX1 is the best game ever and HR is merely decent.

Other aspects tie in closely as well, like the general design of levels and just the pure size of them. When I think about this issue in HR, I always come back that early obstacle of getting into the club and my thought process after getting denied at the door. My immediate thought was "wait... is there a vent 5 feet away in this alley right next to this bouncer" and sure enough there was. That really broke things for me. Amazing how much little aspects affect how I felt about HR.

Drew: Read through all the response here (good discussion!) and I agree that the key is that DX1 way more often felt like obstacles that I could find a solution to (even if that wasn't actually the design) and HR felt like "okay where is the vent, where is the roof access, where is the terminal to hack". I think breaking down why that is the case would go a long way. Maybe it is pure trickery. I agree though that HR felt very mechanical. They clearly looked at what worked in DX1 and translated it but the key thing to translate was actually the essence of what was going on there with the problem solving and choice, not just the way you can get into a building via a vent or with a lock pick.

I think the size of the level really is a pretty big factor. HR felt so cramped. Like you guys mention, being set loose on a couple city blocks feels a lot different than being in a series of alley ways.

Elina: This article is reminding me of the level design in Styx. It feels like these are real places, and so often it's not just a case of simply getting to your destination, but moving in such a way which means you don't run into guards.
The easy route which leads directly to your objective is partroled by guards. However, there are always other routes which are waaay harder to navigate, but can allow you to sneak past completely undetected

Ben: I sometimes get anxious when games seem to be forcing me to commit to a particular upgrade path.

"How the fuck should I know which of these I want," I'll think to myself. "If you think I'm going to replay this game 17 times just to see everything, you've got another thing coming." I'm anxious because I don't want to "miss out" on content, and instead of feeling intrigued and empowered, I feel like I'm being suddenly forced to chose which set of hallways I will spend the rest of the game being forced down and which I'll be sealing off forever.

I really love the MGSV way of doing things. Abilities are tied to the gear you chose to bring with you (or manage to scrounge during the mission itself). You're theoretically able to unlock everything eventually but not overwhelmed by choices to start out with. You're allowed and encouraged to repeat missions and try different approaches, even mid mission, by swapping out gear and buddies on the fly. The limit on what you can carry and the cost of replacing it doesn't preclude changing your plans, but it does encourage some initial planning and experimenting to see if you can make the most of what you have at the moment.

Dunno if any of this might be applicable to Tom's game.

Just wanted to say, I kind of hate when "choice" in games effectively does the opposite and restricts the players to certain types of play for the remainder of the game.

Jabberwok: @Ben - This is why I think games that allow you to improvise solutions based on their rulesets are the best. You're not being funneled in the direction the designers have chosen for your skills, instead you're figuring out how to use the skills you chose to solve whatever problem is in front of you. If the game is actually open, flexible, and consistent in this way, it should be able to accomodate this and not feel like content is being gated off based on your choices.

For instance, I'm pretty sure you can complete all of DX1 (perhaps minus a few secrets) without ever using an Aug at all. All they do is allow for new strategies.

Anonymous: @Jabberwok - I hear that.

Personally, I want to be allowed to check it out Aug and how it works without having to roll up a new character.

Of course this is purely my own preference, and I realize it flies in the face of classic RPG design and what most people that aren't me like most about those games.

Min/maxing and living with those decisions can be really cool, for example, the stakes of leveling and becoming more powerful are raised when the currency to do so is so precious. More unique experiences can be made possible when players are forced to "specialize", and a feeling of "aren't I clever for doing it this way" is perhaps more commonly engendered in the player. Tom's Illusion only Skyrim Diary springs to mind. Any system that encourages that sort of this is definitely doing something right!

That said, one of my favorite types of "fun" in games is learning the systems at play and eventually, hopefully, developing some modicum of skill in using them. When I feel like I more or less "get" 1 system, and I'm looking over at a shiny new system that I'm not allowed to fuck around with at all, I get a bit edgy.

For me, MGSV's approach more or less solves this "problem". It allows some specialized builds (Sniper, Loud and Armored, Stealth CQC, Anti Vehicle) and disparate approaches to mission goals, but it lets me try them all out (eventually) without starting up a new game.

You slowly add more and more tools to your toolbox as you go, but are only allowed to carry a limited number of tools at any one time.

Of course, that you can repeat missions undercuts the narrative a bit I guess, but I don't care, as it's largely ridiculous anyway.

It effectively lets the player play different builds as they chose without having to start up a new game. It also encourages screwing around. Slop your way through a mission and fail some sub-goal? Who cares! Try again. No need to reload a save. There is zero lasting penalty for anything you might screw up.

Exhausted after stealthing your way though 19 consecutive missions? Slap on some body armor, grab an LMG, and hop on your minigun sporting robot. It's ok. You can come back and play this one properly stealthy later.

Ben: @Jabberwok - oops, that anon is me.

Jabberwok: @Ben - I agree. It just depends on the sort of game it is for me. Borderlands without respec would be painful. Even changing classes sucks, having to repeat the same story content over and over. In Diablo 3, I've come to appreciate being able to switch abilities at any time, although I don't think you could in D2, and it never bothered me. I think in sandbox games that are just about developing strategy, and games about min/maxing (something which I'm kind of against anyway, even though I still play them) it makes sense to have that freedom.

But in an actual RPG, still one of my favorite genres, your choices on level up are as much about building your story, defining who you are along with the other decisions that you make throughout the game. So they clearly need to be permanent. An exception to this might be Skyrim, since ES games allow you to go through all of the story content with almost no actual decision-making, so it's hardly roleplaying, anyway. I appreciate that they added the ability to reset skills to zero and get your perk points back once they hit 100.

I'm not sure if I would call DX1 a proper RPG, but it is open and engaging enough that I actually wanted to go back through it trying different builds, and didn't feel like I was just grinding through story content. Also, there is a lot of reactivity, so choosing to play one mission by just gunning everyone down can actually have consequences (though not major ones, really). Not surprisingly, Dishonored is pretty similar in that respect. I still plan to go back and try a more violent, brute force, playthrough. Same with DX: HR, for that matter.

I'm not sure what my point was..... Anyway, in the case of MGSV, with the sandbox, distinct missions, and (I assume?) linear story, being able to switch things up definitely sounds like the way to go. As more and more games incorporate character building elements, but don't really mesh with the roleplaying part, it makes sense to let people pick and choose, for sure. And in games where multiple missions might be pretty similar in terms of layout or objectives, switching up builds is a way to keep it fresh for the player.

Ben: @Jabberwok

I don't love being asked early on to pick a particular playstyle path when it means barring all others. At the same time, It'd probably be even worse to have everything available from the start. Perhaps others share some of this anxiety at some level, but I must admit my version of it is a bit nuts.

My anxiety when confronted with a bunch of non-intersecting skill trees has to do with my limited time and perhaps a fear that I might be "missing out" on something cool, and wanting to do things "the right way".

Wanting to master a game can be a useful impulse to have in a competitive mp game or say, Robotron 2084, but it's not necessarily the best way to approach other more sandboxy/RPG/games with lots of options.

Sometimes I just need to relax. It's a game. Play it however you damn well want, crazy.

Paul Hofmann: Role playing: staying in the role/ character despite difficulties, sticking to your limitations – so it is the gameplay defining early game decisions that make an rpg. DX is an rpg.

Multiple routes are also interesting because the create a fear of the unknown: Not all routes can be explored and thus remain as an open flank, a risk in the players mind (or a missed opportunity) – it makes the world feel more dangerous since you are not in complete control. There be dragons.

Key thing is: the player must not be able to fully survey all alternating routes, they must remain in the dark (even if this withholds content).

rpgdan: One of the reasons I like reading your posts is how you're able to clearly identify what you like in games and then try to deconstruct exactly what in the game gives rise to that reaction. I don't think I have this self-awareness when playing games. Do you have tips to develop that critical play ability?

Anonimouse: Great post. One factor you didn't include in your list of basic ingredients (possibly because it's blindingly obvious) is consequence/reward. Part of the interest of multiple approaches is knowing you'll discover different things on different routes: different amounts of money, experience, equipment, or different bits of story, conversation, or NPC interaction. I say this as someone who used to obsessively retrace every possible entry route in the Thief games to collect all possible loot, and combed DX1 levels to an unhealthy degree in search of those tiny XP bonuses for exploration.

SenatorPalpatine: I really liked MGSV's take on this, using a more open world level design instead of just vents everywhere. I loved Deus Ex HR though, can't wait to see how Mankind Divided improves on the formula.