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The Simulation Dream
by Tynan Sylvester on 06/02/13 04:09:00 pm   Expert Blogs   Featured Blogs

The following blog post, unless otherwise noted, was written by a member of Gamasutra’s community.
The thoughts and opinions expressed are those of the writer and not Gamasutra or its parent company.


Check out my game design book Designing Games (published with O'Reilly Media) at Amazon or O’Reilly.



There’s an old dream in game design. It drives the design of games like SimCityDwarf Fortress, Tropico, The Sims, and Prison Architect. I like to call it the Simulation Dream.

In 1996, Starr Long, the associate producer of Ultima Online, talked about the game before release:

“Nearly everything in the world, from grass to goblins, has a purpose, and not just as cannon fodder either. The 'virtual ecology' affects nearly every aspect of the game world, from the very small to the very large. If the rabbit population suddenly drops (because some gung-ho adventurer was trying out his new mace) then wolves may have to find different food sources (e.g., deer). When the deer population drops as a result, the local dragon, unable to find the food he’s accustomed to, may head into a local village and attack. Since all of this happens automatically, it generates numerous adventure possibilities.”

That’s the Simulation Dream – the idea of making a complex simulation of a story world, which creates fascinating emergent stories as powerful as those you might write yourself. The idea bursts with potential. And it appears everywhere. Early in the development of BioShock, that game had an ecology too. There were three parts to it. Splicers would hunt Gatherers, who were in turn guarded by Protectors. The player was supposed to interact with and manipulate this ecology to survive.

But these dreams shattered. After its release, Richard Garriott said of Ultima Online:

“We thought it was fantastic. We'd spent an enormous amount of time and effort on it. But what happened was all the players went in and just killed everything; so fast that the game couldn't spawn them fast enough to make the simulation even begin. And so, this thing that we'd spent all this time on, literally no-one ever noticed – ever – and we eventually just ripped it out of the game.”

The same happened on BioShock. While BioShock retained some valuable vestiges of its simulation-heavy beginnings, the game as released was really a heavily-scripted authored story. There was no systemic ecology at all. It worked fantastically as a game – but it wasn’t a deep simulation.

The problem is that simulations with a lot of moving parts quickly become complex in the intimidating academic sense. There are so many pieces interacting that the game can easily become too much to understand, predict, or play with. All the interesting stuff in the game ends up lost in the silicon, inaccessible to the human players’ understanding.

And that’s really the key – making complex simulated events accessible to human understanding. Which brings us to a nerdy idea I like to call the Player Model Principle.

The Player Model Principle

The Player Model Principle is this:

The whole value of a game is in the mental model of itself it projects into the player’s mind.

We make a simulation in computer code. That is a computer model of some situation – a dwarven fortress, a prison, and so on. But that is not the only model of that situation designers need to worry about. There is another model of that fortress or prison - the mental model in the player’s mind, which the player constructs while playing the game. Designers create the Game Model out of computer code, while the player creates their own Player Model by observing, experimenting, and inferring during the play.


In play, the Game Model is irrelevant. Players can’t perceive it directly. They can only perceive the Player Model in their minds. That’s where the stories are told. That’s where dilemmas are resolved. So the Game Model we create is just a pathway through which we create the Player Model in the player’s mind. 

The Player Model Principle indicates a source of risk. Namely, anything in the Game Model that doesn’t copy into the Player Model is worthless. That’s what happened with the ecologies in Ultima Online and BioShock. They didn’t enter the Player Model and so degraded into noise. This is a fairly obvious risk and is common in game design – all designers have seen players not understand a piece of their game.

But the Player Model Principle also implies an amazing opportunity. What if we could put something in the Player Model without implementing it in the Game Model? What if we could make the player perceive some event or relationship or meaning that wasn’t even there?

The advantages are obvious. We wouldn’t have to build it or test it. And it wouldn’t add any complexity burden to the game. While this sounds exotic, it actually happens all the time. It’s called apophenia.

Apophenia is seeing meaningful patterns in random or meaningless data. For example, look at this wall socket. What do you see? A face! And not just a face. But a face with a confused, perhaps pained expression. Why do you see that? There is no such personality here. But we perceive it all the same. It’s how we’re wired as human beings.


That ability to perceive personality and intent is a deep-seated human ability. It happens below conscious awareness, the same way you can look at a room and understand it as a 3D space without thinking about it. The only knowledge of the room you have is a 2D projection of it on your retinas. But some silent processor in your brain generates the perception of a 3D environment. In the same way, we effortlessly perceive minds and intentions. It’s why ancient peoples perceived spirits in rocks, water, sun and moon.

Apophenia is powerful and varied. Consider these Michotte demonstrations, named after the researcher who explored them in the mid-20th century.

Michotte did many variations on these demonstrations. It’s amazing how much people see that isn’t there. We perceive human-like relationships between the balls, with concepts of dominance, gender, and intent. Some of the explanations are astoundingly complex. For example, "The little ball is trying to play with the big ball, but the big ball doesn't want to play so he chases the little ball away. But the little ball is stubborn and keeps bothering the big ball. Finally, the big ball gets mad and leaves." None of those feelings existed, except in the Player Model.

This apophenia – this perception of personality and intent where there is none – is the key to making a simulation game work. We can’t simulate the emotional core of a good story on silicon. Computers just aren’t good at handling generalized intelligence, intent, and feeling. But we don’t have to simulate those things. We only need to show the simulation equivalent of moving balls and let the player layer in their own emotional perceptions.

In this way, the simulation is a co-author of stories with the player. The simulation does the logistics and generates some random outcomes, while the player adds the meaning and pathos.

Apophneia example in The Sims 3

Here’s a story someone created with The Sims 3. He created a Sim version of himself and his roommate. Soon, a cute redhead enters their lives. And the redhead goes straight for the roommate, leaving the protagonist frustrated, angry, jealous, and alone.


But none of those emotions are in the game. The Sims 3 has a very simple computer model of social interactions which does not really depict deep human emotions like jealousy and anger. We perceive these things through apophenia – the same way we perceive a small ball fleeing from a large one.

Now the player takes control of the story. He hatches an evil plan involving a cheap stove, poor cooking skills (which cause fires), and wooden chairs.


And the plan works.


This story was co-authored between the player and the game. The game simulated some simple event (attraction between redhead and roommate), and the player ascribed meaning to it (jealousy and frustration) the same way he might have for the Michotte balls, even though that emotion was not actually in the simulatiion. The next part of the story was cued by him when he orchestrated the murder. The game simulated the logistics of firey deaths, but the sense of sorrow and revenge was, again, ascribed completely by the player. Most of this story is apophenia – present of the Player Model, absent from the Game Model.

Creating apophenia

It’s hard to see obvious ways to make players imbue meaning into a game that the game doesn’t actually have. But survey the products that do it well and you see patterns.

Borrow archetypes from real life and fiction

Use the archetypical jealousy plot, the evil stepmother, the good king, the classical hero. This saves exposition since the player already knows the stock character or situation you’re hinting at. This makes it easy for players to fill in absent details.

Allow players to project themselves into the game.

When a virtual character has your name pasted on, it is easy to imbue that character with motivations that are relevant to you. The same goes when the player projects in their friends, house, and so on, into the game. The Sims gains massively from this.

Create uncertain situations with human-relevant values in the balance

This is storytelling 101, but it bears mentioning. The simulation has to create situations that are worthy of being called stories. That means something important has to be in the balance, and the outcome has to be uncertain. Human values must be at stake.

Human values are things like life/death, alone/together, wealth/poverty. The game should revolve around things that affect these human-relevant values, and not descend into a dry simulation of traffic networks or production lines. Such simulations may be intellectually interesting, but will not generate effective stories because they are emotionally hollow.

Express or imply simple, pure, primal emotions

Annoyance is less interesting than fury because of the difference in intensity. Melancholic existential hipster sadness is less accessible than grief over a dead child because that grief is simpler, more relatable, and more primal. If the game has no opportunities for characters to feel such emotions, it is unlikely to generate good apophenic stories. Stories are built from primal feelings, so the subject matter of the simulation must create situations where characters would feel primal emotions.

Drowning in Complexity

So we’ve covered the benefits of apophenia. But we still haven’t solved the problem that killed the ecologies in Ultima Online and BioShock. How do we handle complexity? For apophenia to work, players have to see and understand interesting things happening. And this can easily prevented if they’re drowning in complexity.

Think of a simple system, like orbiting planets. For the most part, each planet only has a relationship with the sun around which it orbits

Simple---OrbitalIf you want to tell a story about each planet, it’s easy. You just look at its one relationship and talk about that. So the Earth orbited… and it orbited… and it orbited. The problem is that while this story is easy to see and easy to tell (satisfying the Player Model Principle), it is also quite dull. We need more interactions, more variation, more unpredictability. We need more complexity.

Now imagine we’ve made a simulation of a village. Each of the hundred villagers has a relationship with each of the others – father, friend, enemy, lover, or acquaintance. Each can work at the fishing pond, the market, the field, the mill. Each can satisfy their own needs at the tavern, in bed sleeping, at the outhouse. The water can flood the field. The outhouse can spill into the market and contaminate it, causing sickness, overloading the hospital, making the doctor work too hard, leading to divorce. It sounds like the Simulation Dream. But there’s another problem now. The connections multiply until the whole system appears as a gigantic hairball of complexity.


Such a system could support some very interesting stories. I just told you one of them. The catch is that it will constantly break the Player Model Principle. With so many relationships, it becomes very hard for players to understand cause and effect in the system, so those stories end up buried and unobserved.

What we want to do is create systems that are smaller and simpler than these giant hairballs, yet have more interesting, comprehensible interactions than simple systems like orbiting planets. What we really want is not a system that is complex, but a system that is story-rich. Story-richness is a term I invented for this article, and a concept that I keep in mind while doing simulation design. It has a simple nerdy mathematical definition.

Story-Richness: The percentage of interactions in a game that are interesting to the player.

Consider every interaction in the game – every crop harvested, every path walked, every work spoken by a character. Of all the interactions happening in the game, what percent are part of an emotionally meaningful story? In a successful game, this percentage is high. Much of what you observe will be part of a story. In a poor game, it is quite low.

Interestingly, real life and most fictional worlds are not story-rich! Most days for most people on Earth or in Middle Earth are quite mundane. It’s only very rarely that someone has to drop the Ring into Mount Doom. Follow a random hobbit in Hobbiton, and you’ll be bored soon. It reminds me of an old war simulation MMO, where players sometimes had to drive a truck for hours just to reach the front line. Yes, we know war is 99% boredom interspersed with moments of terror, but a game about it should not be.

This means that a simulation game can’t be a faithful simulation of its subject matter! It has to be a narratively condensed, intensified version of that village, fortress, or prison. And it has to seem true to the source material without being true to that source material. The Simulation Dream just got harder.

Creating Story-Richness

Like apophneia, the sources of story-richness are difficult to see. But there are some patterns. The basic principle is to avoid uninteresting events and create more interesting ones.

Choose the minimum representation that supports the kinds of stories you want to generate

This is a complex piece of advice that I’ll try to unpack by example.

Imagine we’re making a simulation game and trying to decide how to model food in that game. How many classes of food do we put in? We have lots of options

  • All of them! Cheese, venison, beef, chicken, broccoli, barley, corn, beer, water, juice, and so on. Hundreds of options, each acting slightly differently.
  • Categories by type: Meat, vegetables, liquid.
  • Categories by quality: High-quality, medium-quality, low-quality.
  • One: Food is food.
  • Zero: Food is not modelled and nobody eats.

Which do you choose?

Choose the minimum representation that supports the kinds of stories you want to generate.

The above sentence is fairly dense, so I’ll try to unpack it.

Consider the kinds of stories you want to generate in your game. To what degree are they about food? If you’re making a simulation of a New World colony in 1550, food will be important because starvation is a key driver of many stories in such a setting. The threat of hunger is, one way or another, part of most of the stories in such a setting. So you’d probably want a pretty nuanced food model. In such a game, the difference between seal blubber and vegetables could be important, because a diet of only seal blubber leads to scurvy during the winter, which leads to death. Human values are at stake!

However, if your game is a prison sim, you could make a strong case for not simulating food, or for simulating it in the simplest possible way. Because prison stories are not typically about food. Watch Oz or The Shawshank Redemption and few of the plotlines revolve around who is eating tasty bacon and who is eating cheap rice. A complex food simulation in such a game is likely to just add a lot of systems and noise that don’t contribute anything to the stories players care about. This complexity would be better added to the systems for gang membership, shiv combat, or friendship.

In general, lean on the simple side. You don’t have to simulate that much. The game is a co-author, not an author. It just need to hint at what is going on - the player’s apophenia will fill in details.

Use hair complexity for cheap fictional flavor

Hair complexity is my term for pieces of the simulation that don’t affect anything outside themselves.

I call it hair complexity because it sticks off the main ball of relationships without feeding back into it, like the hair on your head. Such hair complexity can be ignored by players who don’t wish to deal with it, while more interested or skilled players can pay attention and get its full flavor. It’s like the flavortext in a card game.


  • In Dwarf Fortress, each dwarf has an appearance. These appearances do nothing, but help players form mental images.
  • In Prison Architect, prisoners have criminal histories. They do nothing (so far), but they add flavour if you want to watch a certain prisoner.
  • In The Sims, sims have conversation topics represented by images in speech bubbles. For the most part, these topics don’t matter. They could talk about sailing or sports; it makes no difference. What matters is that they are talking and their relationship score is improving. But players can, if they wish, watch the stream of images and imaging a thread of conversation leading from money to cars to a mutual friend.
  • It was mentioned to me at a conference that hair simulations (e.g. Tomb Raider) are, ironically, hair complexity, since they don’t affect anything else in the game. Har har.

Hair complexity is cheaper to design. And since it doesn’t feed back into the larger game system, it doesn’t add complexity – just a bit of interface burden.

Eclipse Colony design case study: Crop Growth

Let’s put this into practice and look at a small example of a simple system design problem from my game Eclipse Colony. I faced this problem in early May 2013. Get ready for design nerdiness – we’re about to do some heavy analysis on what seems like a simple problem.

Task: Currently, plants just grow on a timer and can be harvested when the timer expires. But it’s odd that plants yield the same regardless of whether they’re exposed to vacuum or not. I’d also like some notion of farmers tending plants to help them grow and yield more. Fix these issues.

In this situation I wrote several candidate designs to choose between before I decided on a path. Here they were:

Option 0 – Skip it

  • Do nothing. Let plants grow the same on the same timer anywhere.

Analysis: Option 0 should always be there. There are always a lot of things we could work on in a simulation game. We could make a better friendship system. We could add animals or new weapons or wild plants. We could improve world generation. We could differentiate cultures, make a religious belief system, or add more nuances to the combat model. You have to be sure that what you’re doing is actually somewhere near the top of that gigantic priority list, because it’s easy to get tunnel vision. In this case, I decided that crop growth was worth working on because starvation is a big part of life in this fictional space colony. Furthermore, the missing behaviors had been bothering me in a direct and present way during playtests. It was a problem crying for a solution.

Option 1 - The yield variable

  • Each plant has a variable called yield.
  • When the plant is harvested, the amount of food that appears is based on yield.
  • Each time a farmer tends the plant, yield increases. Once tended, plants can’t be tended again until a certain time has passed.
  • Damage to the plants reduces yield.
  • Being left in vacuum reduces yield.

Analysis: I liked this system at first because it seems to reflect the fiction well. But there’s a big caveat: a new variable (yield) is undesirable complexity. Also, how will yield work for wild, unfarmed plants in the future? Will they even have it? How does it interact with more normal damage from fire or explosions? Do plants also have a health variable? The added complexity and edge case ambiguities made this seem a poorer choice.

Option 2 - Use the growth timer

Remember that plants already have a timer that counts down until they’re finished growing.

  • Each tending operation speeds the plants towards finishing growth.
  • Damage to the plants reverses their growth.
  • Being left in vacuum reduces plant growth.

Analysis: The simplicity of this is good because it doesn’t require any new variables. But this doesn’t capture reality – real plants don’t just grow slower when deprived of care or when damaged. They grow poor harvests, but they still flower around the same time. This system could lead to absurd situation like crops being slightly damaged repeatedly and just never becoming harvestable. Or plants being very well-cared for and being harvestable on a weird accelerated schedule.

Option 3 – Re-use the health variable

  • Plants have the standardized health variable.
  • Final harvest output is proportional to the plants’ health.
  • Plant health steadily decreases at all times (due to insects etc.)
  • Plants are damaged by vacuum and normal damage sources like fire.
  • Tending plants is essentially repairing their health.

Analysis: There are no new variables or interfaces, which is good. It captures the essence of the idea well enough. It even expresses the rotting of grown plants, since they lose health over time after they finish growing. This seems like the minimal representation that captures the subject matter and supports the stories I want the game to co-author with the player.

I ultimately decided to re-use the health variable. But even this could still change as the game gets tested more.

The Simulation Dream Reborn

It seems like maybe we killed the Simulation Dream. You can’t just simulate a super-complex world because players won’t understand it. And even if you did, it would be boring, because even Middle Earth isn’t very story rich.

But the Simulation Dream lives on. We just know we have to approach it very carefully. We can’t blindly simulate everything, because most things are boring and people can’t understand over-complex systems anyway. We have to carefully craft a condensed system of simple, understandable hints that cue players’ apophenia to do the heavy lifting of ascribing emotion and meaning. We have to make sure that system projects well into the Player Model. And we have to make sure that much of what happens in it concerns powerful, primal human emotions, not logistical details.

But if we do all that, I think the Simulation Dream is still in our reach.

Check out my game design book Designing Games (published with O'Reilly Media) at Amazon or O’Reilly.

Twitter: @TynanSylvester

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Lars Doucet
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Wow, this article went up nearly simultaneously with my writeup of a free-floating economic market simulator:

What you've written here is basically the perfect "before you get drunk on emergent complexity, please consider..." counterpoint. Thanks for writing it!

Tynan Sylvester
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A good related read! Checking out your article now, I'll post a response on that page.

Edit: Long-ass response posted.

Bram Stolk
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Interesting read, thanks for sharing.
What is the name of the game that features hours of boring travel to the front lines?
I think it is quite briliant: the boredom will heighten the intensity of the experience when you actually do get to the front, and see an enemy.
Getting killed in this game would be so much more dramatic.
Some time ago I finaly realized how rare a 'kill' on a real battlefield actually is, from a killer's perspective.
If in a war, N soldiers partake, and M ( < N ) get killed, kill count per soldier is almost always 0.
Compare this with hollywood or video games.

Tynan Sylvester
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Interesting note about real war kill rate. I think the kill count in real war may actually be far lower than even you're estimating. Most kills in war are accomplished with long-range weapons like artillery and bombs. You never see who you killed. Even gunfights are usually fought outdoors over distances of hundreds of meters. You'd never see more than a short flash of an enemy fighter moving on a horizon. You'd just fire at their general position and eventually, maybe, hit someone, and you'd never know about it. And he'd probably just be wounded, not killed outright. I'd bet the number of people who have looked at an enemy and shot him in a modern war are pretty darn small.

The game was WW2 Online (from long, long ago).

It just occurs to me that games like DayZ feature this sort of very-slow-with-spikes gameplay and make it work. But even that world is far more action-intense than any similar real situation could be. Your lifetime is still measured in hours of playtime, not weeks or years.

Raph Koster
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Awesome article!

For the sake of providing a detailed cautionary example: Ironically, UO tried very hard to be this simple behind the scenes -- its sim was very simple! But of course, sheer number of actors led it into the complexity trap, and I wrote three articles about it:

Part three goes into exactly the problems you describe here.

But many of the most successful elements of the game, which did build on the above to some extent, were pure apophenia designs; see this piece:

Tynan Sylvester
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Well, I can imagine no greater compliment than the grandaddy of simulation complexity blogging and design enjoying my article about it. Thanks for dropping by.

And I do believe I've read some of those articles. In fact, I'm pretty sure they inspired a chunk of this one. You know how it is - you read something, it falls into your brain and six months later you have an idea from it but you can't quite identify the source.

I loved the idea of the generated nonhuman speech. That's genius.

Dave Mark
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Related to apophenia is the famous Heider-Simmel Demonstration. I talked about this (and other things) in my 2012 GDC AI Summit lecture on psychology and AI. It is yet another example of how we will construct narratives where none exist -- even with non-anthropomorphic objects like shapes.

Watch the video below and then ask yourself "what did I just see?" Then show it to other people and ask them the same questions.

Follow-ups are questions about WHY certain movements evoke different emotions, etc.

Tynan Sylvester
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I love this. Wish I'd had it for the talk.

Simon Chauvin
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That's such a great read. At first I thought that you were trying to explain how simulation is a trap, but it's actually the other way around! It has to be thought out carefully and we have to know what we're trying to do rather than simulate everything. I'll make sure to keep all of this in mind.
I really like your last example, it's perfectly demonstrative.
Also, your article made me think of the "A Certain Level of Abstraction" article of J. Juul (
and G. Frasca's article on "Simulation versus Narrative" (

Tynan Sylvester
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We need a better term for the extraction of game mechanics from the systems of a real or fictional world. "Abstraction" isn't quite right. I was actually going with "mechanicalization" in this talk for a bit (in the sense of "making something into game mechanics") but took a breather from that lump of syllables.

Just a thought. Thanks for the articles; thought-provoking.

Adam Buffett
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Couldn't you just call it "Modelling" or "Simulating"? As in... modelling real-world mechanics inside a game.

(Great article btw, along with the economics engine article too)

james vaughan
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Great article - completely agree with it. I went through a similar mental journey when designing Plague Inc. - how to make cool things happen and let the player influence them

Tynan Sylvester
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I am now back-stalking you, hour-long interview and all. Nice game, Mr. Vaughan.

Karl E
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Great post. But your view of "story-richness" is too reductionist. Any good fictional experience has to include both a simulation of everyday life and story and transcend these matters. It is only because of the descriptions of Hobbits in their everyday life that we care about whether someone drops the ring into Mount Doom or not. This is usually neglected in games - your first task is usually to save the world, it's just that you never got a feeling for the world you're saving so you don't care about it.

Simulation of everyday life might really make a difference here in grounding stories in a virtual world. But there are no shortcuts. If, as you suggest, you from the outset set out to make a "minimum representation that supports the kind of stories you want to generate" you are not exactly creating the conditions for transcendence. The result might not be failure but video-game mediocrity.

Tynan Sylvester
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You're right of course. I may have been approaching this from the wrong angle. Perhaps the solution to stories being lost in the noise of complexity is not to make stories more frequent, but to point them out more effectively. There may be a limit on how real-feeling we can make a simulated world while still pushing up its story-richness. If every character is in some super-dramatic story at all times, the feeling of reality might be a bit weak.

That said, I did note that the goal of increasing story-richness comes with the implicit side-goal of making the world continue to feel real and reasonable. If it seems like a world-spanning soap opera, we've just found a new (and very interesting) failure mode for the design.

I think this is a question that needs more practical exploration. Working on it...

Alfa Etizado
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But what about when the player starts noticing how deep the simulation goes?

I feel in a lot of games the important thing is the feel of being in another world, not only for simulation games. But in simulation games this feel is even more important, and more powerful. At the same time, these games invite you to spend a lot of time in them and understand their systems. For me at least that breaks that feel, it is the moment I understand the blue ball does not run away from the red ball.

So I think the noise you mentioned earlier is important. Something that's too complex to understand but that constantly surprises you in the long run, just to preserve the feel that you are in a living world. In turn, this feel allows the player's imagination to keep running and so Apophneia can keep happening.

Players don't stop to watch things, so they'll miss out a lot of stuff at first, but if the player stays long enough (and if the game affords that) he/she will notice the noise, try to make some sense out of it. Maybe the noise doesn't even need to be actual noise, just fake simulated noise, player model noise. But I think it is important for it to be there one way or another. And I think it has to be noise, because I think it has to be something the player never makes sense of. It doesn't even need to be present all the time as long as it shows its face every now and then.

Of course this would probably be a waste of time if the game isn't long enough.

Tynan Sylvester
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I think a lot of systems-driven noise never becomes understood in the end. See UO and BioShock. In the end all the systems driving this noise could be replaced by random generators. From the player's perspective, it looks the same. Noise is noise.

I think what you're getting at is things that look like noise to begin with but become comprehensible over time. And this is good, healthy game design - a perfect description of a nice learning curve.

But I don't see the value in doing the work to make a system the player never makes sense of. Might as well pull a Raph Koster and just start making random systems that people will layer meaning onto (see his last article in the comment he placed above).

I wouldn't say the magic breaks when I know that the blue ball does not run away from the red ball. After all, I knew that most of that story about The Sims wasn't really true. But it was still entertaining, at least to me. I know movies didn't actually happen, but I still enjoy them. It's the story told that matters, not the story that occurred.

Thomas Grip
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Great to see someone else writing about this. I gave a talk at this year's GDC on the same topic (that much of the game happen in the player's mind), but from a different perspective.

Script here if you are interested:

Tynan Sylvester
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I think it's interesting how we seem to be independently driving at the same ideas.

One strong distinction I'd make is that I don't think the player has to be prevented from understanding the mechanics behind the apophenia. I know the Sims aren't feeling what they look like they're feeling, but I can still tell myself the story about it. Perhaps this works differently in horror games.

I do love your focus on giving up challenge. I had a whole talk section about this that I cut (stating that sim games are story co-authors, not simulated opponents to defeat). A lot of really interesting stuff emerges when you dump the deep assumption that games must be challenging. Non-challenge-driven design is, to me, a rich blue ocean in game design. And there are lots of vectors into it, including 1st person horror and world simulation.

Nice work with Amnesia, btw.

Nick Harris
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Well, I was so impressed with how well you articulated these issues that I have just been to Amazon to buy your paperback: 'Designing Games: A Guide to Engineering Experiences'. What interests me is to simulate a system so that you only pay the computational cost for what you see. So, rather than iterate the movement of a train around a city and know all the timings of the stops it makes, your character would look at a section of the overhead track visible between some buildings and the game would know that it had to check if you could see some train carriages there based on a time-based function, which ones there were from what scheduled train and what position they were in - e.g. rather like choosing to observe only a slice of an analogue clock, yet seeing the hands pass through that slice because the internal clock time fell within the time interval that was covered by that slice, you may see the hour hand or the minute hand or both doing the rounds, just as you may see two trains pass each other in their circuit going in opposite directions (yet, when the clock hands are not under the slice there is no rendering cost, just as if you were to look away from the train track). This is all probably an established technique in the industry that I just haven't stumbled across because I am an amateur, but I am hoping to use this and some hierarchical level of detail emulation approximations standing in for actual simulations to allow a form of 'Dynamic Scoping' in which extraordinarily large systems appear to be simulated (the trick being that the ground level stuff gets fuzzy as you observe from an ever greater height or change to another distant location). I simply can't iteratively calculate the next state of every little thing for every little thing happening on every street in every city in every country of every continent on every planet of every star system of every galaxy in the universe. It has to all be smoke and mirrors and mathematics.

I also liked Raph Koster's generated nonhuman speech mixed in with the occasional key English word and on reading through some of the comments there I felt it worth mentioning the late Douglas Adams' Spookitalk system that was used for Starship Titanic:

However, it seems that the trend is to move towards voice actors recording scripted dialogue even in multiple languages to evoke a sense of place:

Whilst it would not be impossible to expand a Spookitalk-style 'dictionary' of words to encompass all these extra foreign languages, their intonation and emotional tones as alternative recordings it would probably lead to a rather artificial result compared to a dramatically invested human actor. It is really tough to see how a game could be flexible about what its characters said, indeed, procedurally generate dramatic dialogue based on their modus operandi and what little they wanted to reveal about themselves to who they were with. The only option I can see is to make your protagonist deaf, foreign or alien and then have legitimate reason to be able to subtitle everyone's burbles and snarfs. The upside to this is that localisation becomes a lot easier as you only have to translate the text and maybe a cluster of key English words pertaining to objectives.

Again, many thanks for the excellent article. I look forward to reading your book.

Tynan Sylvester
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Raph Koster's article he posted in the comments above has another example of this static simulation-of-simulation you discuss. It's been done in many forms in many games. Unfortunately it basically breaks a lot of kinds of simulated worlds; their behavior changes at different levels of detail. Which makes sense; we can't expect a low-detail version of a simulation to have the same depth as the high-detail version.

Hope you enjoy the book!

Brent Gulanowski
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"gigantic hairball of complexity": I LOL'd. As someone who adores the Simulation Dream, this article was a real eye opener.

You glossed over the variation of appreciation of simulations shown by different audiences. Some people really like the details of complex simulation. Of course, they have to be able to observe those details and even participate in them, either as a god or an individual. There is also something to be said for simple appreciation of the inner workings, but I suppose such people might make a tiny market.

You might have also been too quick to dismiss the story potential of everyday life. I wouldn't argue that watching a farmer plow his fields, or similar mechanical work, would be interesting. But for the same reason, those kinds of things aren't usually interesting in simulators, either.

Any relationship that invokes changes in behaviour should be an opportunity for story and apophenia. If people will attribute emotions to the actions of non-living things, they would certainly attribute them to characters engaged with one another. If these relationships are hidden, or irrelevant to the central interest of the game, then I have to agree with you.

The Simulation Dream is a sort of holy grail for solving problems in creating believable game worlds. Perhaps these issues are only grating to a small number of players. Maybe in most cases they are better addressed in other ways. Like making sure that players' attention is drawn elsewhere.

Simulations are interesting in their own right, however, and not just to developers. Some players feel a certain frustration in these enticing game worlds which look so real, but are so superficial when you look closely. I suppose if you never look, you'll never notice. But the promise those worlds offer is very seductive. UO may not have afforded much opportunity for trying to smell the roses, as it were, probably because you'd get shanked and dry looted the minute you turned your back.

But Bioshock's world was, at least to me, far more interesting than the gameplay. I wanted to put down my weapons and just explore. And the fact that you couldn't do that, or that there were no NPCs that represented anything but hostile combatants, was perpetually disappointing. (I tried to read the novel, but unfortunately, and perhaps this is an equally important point, the attempt to explain the world's origin did not work; it made it obviously silly, versus just taking over an island or a small country.) I've heard lots of criticisms of Bioshock Infinite for egregious violations of believability and irritating shallowness on the part of the NPCs and the overall world. I don't suppose it's harmed the sales numbers, however. Certainly the nonsensical behaviours of characters in Bethesda's RPGs haven't hurt them in the slightest.

I'm personally still hopeful that first-person simulators will soon take off as a genre. I don't want to be the overlord; I just want to be an exceptional participant, and enjoy the visual wonder of an open world that lives and breathes and changes, on its own and in response to my avatar's actions. Mostly I want it to _feel_ as real as it looks. (As a developer, I realize that the onus falls squarely on my own shoulders, but it's a terribly daunting task for an individual.)

Tynan Sylvester
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True that different people have different appetites for simulation depth and different abilities/willingnesses to go through the learning curve necessary to appreciate such simulations. Really, many/most people don't have any appetite for simulation at all. They only watch movies. On the other end of the scale, we find Eve Online and Dwarf Fortress fans - a small player base, but a devoted one because there are so few products in that space. To me, deciding your depth of simulation is largely a market positioning decision. Mainstream simplicity with lots of competition, or niche complexity with just a few competitors?

I think BioShock worked more as a static portrait of a world than as a simulated world. You wanted to drop your weapons and explore, as did I. But I just wanted to look around and absorb what had been placed in the world. My desire to explore wasn't based on a desire to watch goings-on or interact or understand something happening. Only a desire to inspect the 3D canvas that Irrational painted for me. That's not simulation; it's static content.

Mike Weldon
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This was a great read. I just wanted to mention that I hope your plants can spontaneously reproduce, otherwise all your wild plants are going to be dead after a while. Or maybe you just don't have wild plants. Also I would say that, based on real life backyard experience, if your plant takes too much damage, it might not produce any fruit at all. Anyway, it seems like a good solution which I might pilfer for my own apophenia sim. :)

Tynan Sylvester
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Currently there are no wild plants. Though it's a very strong possibility that there will be some some day. And thanks for reading.

Joshua Darlington
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I put a lot of thought into the simulation dream from a writer's perspective. Modelling character behavior without some sort of cause and effect simulation is a bit iffy. My conclusion was that the quickest path to character simulation and social simulation is augmented reality. Plug real people into the social space and they they just need some minor tweaks to collide and create drama.

I think that human memory can offer some ideas on how to handle simulation. The brain has all sorts of bottlenecks for throwing out useless information, it consolidates during dreams, and then when people remember things - the compressed files pass through creative centers to reimagine the most outstanding qualities.

Tynan Sylvester
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Ever played Werewolf? Or The Resistance? I don't really think you need AR to do what you're talking about; you just need a couple cards and willing participants.

Joshua Darlington
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I keep on getting invited to werewolf events. I will check that out.

My point is that personification in computer games and connectivity in computer games is a perfect match. AR can be the rebalancing simulation with reality to make the best use of resources.

That's why I would advocate putting the human game master back into RPGs. It avoids chinese room problems with simulation(syntactical rule based limits). A real time human can shape a simulation in a way that amplifies drama by the artistic use of human biases and background.

Luis Guimaraes
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It's been a while since I /really/ liked an article around here. Needless to say it's bookmarked in a privileged spot. Amazing work, thanks a lot for sharing this.

Bioshock would have been awesome that way thou. I spent some time in each in predatory stalking of the NPCs, they always had something going on and a good line to randomly drop and a random encounter to end up in firefight between themselves. Then I'd go around and they all spawned again and different events followed.

I spent many (5 to 10) spawn-cycles in each level. It was great, but not as rich as described in the article. Sadly. Very sadly.

Tynan Sylvester
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Awesome to some of us, but as I understand it (I wasn't there) this level of complexity turned out to be:
1. Too niche for many gamers. See: commercial failure of System Shock II.
2. Clashing with the very specific story the studio wanted to tell.

In the end they had to choose between a soft story and niche market on one hand, and a strong, heavily scripted and authored story and a broad market on the other. They went with #2, and I don't blame them.

But really, even the stuff I talk about always sounds better than it actually comes off. The point of that piece of the article was that it didn't work as everyone hoped it would. The ecology sounds good in description, but in play it's just noise.

Rosstin Murphy
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Excellent article, I think about this a lot when designing games. This is the power of drawing on experience and tropes, especially when designing a game without a driving narrative force.

Kyle McBain
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This is the second article that inspired a comment about story being used as a tool. I love the idea of story richness minus the extensive narrative. It is derived from sensory rather than a writing team. I love when story is used to give the player their abilities and dictates needs and wants. I like when it is not so much the backbone as it is a tool and allows for the player to do more and experience more without realizing it.

It makes me wonder about larger games, how much is simulation and how much is deliberate design.

Also, I think it is important to note that apophenia is driven by sound and feeling (controller vibration/movement) as well. Or it can be a tool that affects the player directly, like keeping a character from being able to move during a frightening scene.

Yup loved this article. You're not a nerd, you just know more than most people. We're not children. It's okay to be smart.

Aubrey Hesselgren
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I really loved this article. Crystallised a lot of thoughts.

Recently, I've tried to only add features which I can represent in intuitive/naturalistic ways. That led me to question "what would I want to avoid representing?". The Sims example is great. You sorta don't really want to tell players explicitly how AIs come to decide things, lest those AIs are mental-modelled into human-looking-AIs. (It has a fuzzy model underneath, and until you "get it", the behavior comes off as convincingly noisy)

Modelling some obviously deterministic behaviour in character/AI mechanics is fine, especially when it's something that anyone would do (reacting to a fire alarm going off), but perhaps, if their underlying complexity reaches a level where emergent complexity/perceived noise is the net result, we can forgive it: the metaphor of an "irrational human behaviour" is a sort of envelope to allow for this sort of hidden complexity?

The "otherness" is shorthand for "they may have their own logic for what they're doing, but you haven't seen what they've seen, may never quite understand it". And that's very human.

Perhaps there's a slight taboo to break, in terms of "every game system must ideally be grokable". Maybe there are acceptable ways, which don't involve random number generators, where outcomes are noisey and their cause invisible to the player, which just make character feel a little less like complex deterministic behaviours that we want to deconstruct, like part time sociopaths?

Droqen is who I am
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This was a lovely read :3

I think it's disappointing that the reaction - in, specifically, Bioshock - was to rip the simulation out of the game. I'm sure they tried some things before removing it, but I can't imagine it'd be unfeasible to just... you know, make it harder to kill everything. ):

If the obvious path of least resistance is 'ignore the systems' then that's what will most people will do, regardless of how interesting the system's internal logic can be -- and I think a lot of game developers are afraid of forcing a player to interact deeply with complex systems.

so, hypothesis:

1. For a fraction of games, complex systems are prototyped, attempted
2. Most of them give players an easy way out, making interaction with the system mostly optional
3. Devs see that players are using the easy way out & ignoring the complex system
4. Complex system is removed because nobody is interacting with it because there's an easy way out
5. ):

Tynan Sylvester
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See my reply to Luis Guimaraes above. You really do lose players by creating complex systems and requiring that people understand them. Worse (for BioShock), sim systems are for unscripted story generation, which conflicts with the game's well-told authored/scripted story.

Droqen is who I am
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Yeah, freedom is the worst thing if you ALSO want to tell a prewritten story. There's really no way to do it without reining in freedom to the point where such things as complex systems become smothered to the point of... uh, well, you know. To the point of taking them out because nobody was experiencing them.

But you lose players by removing complex systems too. No matter what you do, you lose players and you gain other players and your existing players' opinions change because the game has changed.

Anyway! I'm not really making a point yet. I think the greater thing I wanted to say was that you can create interesting systems that will engage people, and it isn't always apophenia that makes them engaging. It's one way -- and it's a very interesting and powerful force which can make systems engaging in a human way --

but it's not the only way by which we'll reach the Simulation Dream.

Droqen is who I am
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also, that's a really nice term. simulation dream.

Kevin Reese
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My goodness Tynan Sylvester, stopping writing these fantastic and intelligent articles and book-lengths work and get designing more games :) Game fans who sometimes dream of the 'Simulation Dream' desperately need you working on some gaming projects, because the majority trend has been, in the last long stretch, seems to be mostly working towards the opposite: reduction of complexity, 'streamlining' fun out of games, limiting gamers' choice, and less randomization and variance.

I certainly subscribe to your Player Model Principle theory.

For example: currently playing a new season of Football Manager. The drama my own brain imagines around my contract negotiations with my completely randomized, fictional soccer stars is much more engaging -- for me anyways -- than following the standard story-narrative of well-rendered & voice-acted game characters in my game of Oblivion (for an example off of the top of my head).

I think, overall, many games rely too heavily on the ill-fitting constructs of film narrative when instead they should be focused on creating a world that gamers play in, with their imagination, as only games (be them pen & paper RPGs, board games, or video games) can deliver.

Tynan Sylvester
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Working on a simulation game right now. And yes - I'm hoping that unmet demand is there in the market. I'd like to be able to make another game after this one :). Email me; I'll send you a reminder when the first pre-alpha comes out soonish.

Agreed on the overreliance on filmic elements. I think if someone really wants something 'cinematic', they'll go to a cinema. Also funny to note in the context of this article - a movie is nothing but hair complexity. Nothing feeds back into anything because there is no system. Its complexity graph is just a long string.

Kelvin Autenrieth
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Lovely reading, thanks for that =)

I have been thinking about some general problems regarding the Simulation Dream (Didnt know the term till now, yet it fits perfectly), where I discovered a couple of issues that contradict each other. (Game and Simulation).
Simulations, or complex dynamic systems as I refer to them, are constituted by evolving over time. That means that the outcome of specific decisions and actions cannot be seen within the next moments. Even little insections can have not expected effects. Games in contrast are often defined as systems that have a clear and direct feedback. From a psychological and motivational point of view, this is described as self-efficacy. Here I see a conflict, because the result a player perceives can often not be related to a specific action he did. Thus he tends to feel not be in control of the system. In many cases, this is because of the inherent complexity of a Simulation.
The second point is the intransparency of genuine Simulations that a viewer/player experiences. Classical Simulations have highly cross-linked implicit variables the player doesnt know about. The most familiar example would be the satisfaction-index of the Sims Game or any other equal Game/Simulation. Some of them are quite easy to get, but in the most cases players are just seeing a gigantic black box with no motivation (and/or cognitive strategies) to reconstruct all these implicit models. This results in a trial&error-behaviour, what is clearly a no-go in game design.
I have no answers how to solve this yet, but getting to the primary issues is imo the first important step to get there.


Tynan Sylvester
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Why, thank you very much!

Think before we can "solve" any of these problems we need a clear problem statement. Which means we need to ensure that there is a problem at all with players having limited/obscure/poorly-defined influence over the system. What if it is okay for the sim to do things the player doesn't expect? Or for them to not be able to get what they want?

This is something I've been mulling over and more and more recently. We're used to thinking of games as really clear action-feedback systems, but is this really necessary? What if you take out the traditional competitive and goal-oriented elements of the game? Then the game just becomes a story co-author, kind of like I talked about in the article. And when it's a story co-author, there's much less need for it to be predictable or interactive.

I can imagine a sim game with nearly zero interactivity - just a system to watch and enjoy. Consider Gratuitious Space Battles, where players merely deploy their fleets and watch battles play out without interacting at all. It's still a fascinating simulation to watch even though all the choices are made before it even starts.

As I say, this is still something I'm mulling over. I think we draw a lot of assumptions across genre and design boundaries when we should probably be leaving them behind. The assumption of control and feedback may be one of those.

Kelvin Autenrieth
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After heading through the first pages of your book (that I got today), I think I understand what you mean. You offered a quite suiting definition for a game (an artificial system for generating experiences). We could use this point of view also within the game-vs-art debate that I am observing for a long time. My argument here would be, that there wouldnt be any difference between any kind of an (virtual) interaction-system and a game in the strong sense (goal-oriented etc.).

If we leave the idea about control and feedback behind us, what would be new "phrases" about a game? The old one clearly doesnt make sense anymore: "Lets play a game" is classically mostly about competition. And competition always implicit a social behaviour. Maybe this motivational/emotional aspect needs to be refitted into more cooperative tasks.
For myself, I spent hours together with friends experimenting with the mechanics of a game, while discussing possible options to solve a specific ingame problem. Maybe this is one way to go.
I am also looking for player-typologies that could serve this kind of understanding a game. Maybe the "Manager" is one:
Nevertheless it just includes some of these new thoughts.

I am a bit biased anyway, cause I work "on the base" and doing lectures and workshops for non-gamers what means to have a clear view about (digital pc) games. Telling people about the motivation and meaning of gaming requires often a clear strike that even non-gamer get. Though I love the academic discussion about games, Ill try not forget the public argument that can get through.

Daniil Sarkisyan
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I have enjoyed this article very much, as it touches on a sensitive nerve of the outcome for game player.

IMHO the "Player Model" is not just an important part, it is THE only tangible thing a player gets for all his time and effort consumed by game. For example, if one builds a simulator to train pilots or London bus drivers, it is clear that the whole point of such game is to help player construct a "mental model" as close to the real process as possible. Obviously, a minimalistic design will be counterproductive in such cases.

If one designs a game whose sole purpose is to burn gamer's money in exchange for "fun", you might want to aim for complexity just above "siting back and watching TV". Simple mental model, self-adjusting difficulty so that the player can forget about unresolved complexities of the real world and enjoy being in control. The amount of sugar on toxic waste (I mean "fun" on wasted time) is hard to predict due to natural human heterogeneity. Yes, one could try to aim for a niche, but IMHO it will be much more beneficial to dynamically measure player's response and adjust the difficulty. Slower reaction, less precise aiming ... ok, maybe the gamer is tired after a bad day ... let's make it easier for him today.

As for the conflict of preset storyline and dynamic game ecology... have you looked into "Control Theory"? A surprisingly good way to make your simulation "track predefined trajectory" is to design hidden "input variables" that receive "dynamic feedback" computed from linearized "tracking errors". For example, this is how a modern plane is controlled with "fly-by-wire" system. There are plenty of grad students in Department of Mathematics that will be glad to do the scary math details.

Tynan Sylvester
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Adaptive difficulty systems are powerful. But I'm always conflicted on using them. I think they deny the extremities of the experience from those players who want them. E.g. You can't really struggle with AD in place. And those crazy-hard monster invasions that lead to such great drama in Dwarf Fortress can't happen if we require that the game be balanced.

This is why I'm leaning towards a design philosophy that actually denies the concept of difficult altogether and focuses entirely on the quality of the generated stories. At least for simulation games like mine.

The same goes for any system that suppresses runaway feedback. It keeps things on track, yes... but then you're on a track. Tradeoffs.

I should look into Control Theory, I never have and usually there's lots to learn from non-game-designers. Thanks for the heads up!

Ben Serviss
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Had this on my to-read list for about a month and finally got around to it. You did not disappoint! Lots of great thoughts and jumping-off points for further reading. Although:

"It was mentioned to me at a conference that hair simulations (e.g. Tomb Raider) are, ironically, hair complexity, since they don’t affect anything else in the game. Har har."

I'd say this is the opposite of irony - appropriateness. Now, if hair simulations ended up *not* being instances of hair complexity, then that would be ironic indeed :)

Tynan Sylvester
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You are completely right. I can't believe I misused the word ironically on the Internet. Shameful!