Musing: Chris Taylor's Call to Action

A lot of people have thoughts and ideas about game design. For example, there's Chris Taylor, famous for the RTS Supreme Commander (and it's spiritual previous game, Total Annihilation. Famous mainly for being an also-ran to StarCraft ;) ).

He wrote an article about games. The crux of his article is that games are two hard. Games punish players and they should not do so.

In essence, he's putting forth a notion of design: that games should avoid punishments. That a game is "better" if it does not punish the player, if the player is easily allowed to progress through the game and see more stuff.

The fundamental flaw with his notion is this: it's not objective. It's subjective. It doesn't work as a credible theory of design because of this. His argument isn't that games that use strong Risks in the Challenge dimension are broken; it is merely that some people won't play them.

So?

A proper Theory of Game Design is not intended to say what the most people will play. Ultimately that is a subjective notion, one that changes over time based on what the population wants. An objective Theory of Game Design's purpose is to aid a game designer in being able to tell if a game is functional, as well as describe how functional it is.

My section on pathologies does not detail subjective problems. Something is pathological if it is objectively broken. There is some subjectivity to it, as the Situation Model does model a degree of subjectivity in its representation of the player's attributes. The Situation Model only goes so far as to allow the game designer to assign a generic value to a player's attributes in an area. A kind of, "You must have this much reason to pass this section."

Given that, is it possible to have a game who's Risk dimension is too great? For a particular player, and generalized over a number of players of similar mindset, yes.

As an example, the Risk for being on one's last life in World 8-4 of Super Mario Bros is enormous. Fail, and it's back to the beginning for you, where at best, you'll have to trek through 7 levels before getting back. As children, this risk was somewhat acceptable; children tend to have more time and tenacity on their hands. Plus, children get games when their parents are good and ready to give them to them.

Even so, Risk can be mitigated by another factor: how much fun it is to play. Super Mario Bros. game mechanics are rather enjoyable. While the early levels do get boring after a while, even a seasoned expert gets a thrill from some of the World 8 levels. If a game is fun enough, Risk can be averted.

However, there is one problem. While Chris summarized his position as wanting less Risk (using different terms, of course), that's not what his article actually described. The description of why he doesn't complete games did not deal with Risk; instead, it dealt with Challenge as a whole.

He says,

For one reason and another, I was never able to complete them because at some point while playing, I would hit a "blocker." (A blocker is a term that game designers use to call a part of the game that stops the player's forward progression because of a complex puzzle, or arbitrary twist in the game.) When I hit a blocker, I give it a couple of tries, decide that this seems like a great place to take a break for the night, and lo and behold, the game begins to collect dust and I never play it again. That's the story for most games on my shelf.

That is not an aversion to Risk; that is an indictment of the entire domain of Challenge.

Do videogames need Challenge in order to be videogames? No. The definition of videogames, as I present it, does not explicitly or implicitly require Challenge. It only requires interactivity and the intent to provide enjoyment.

However, do games, whether in videogame form or otherwise, need Challenge? Absolutely; Challenge is at the core of games.

Look at the difference between Chess and Tic-Tac-Toe. Why is Chess played at high skill levels, while Tic-Tac-Toe is considered a child's game? Because Chess provides a much greater degree of Challenge. Chess played against a tough opponent requires a great deal of Knowledge, Reason, and Comprehension in order to be successful. By contrast, Tic-Tac-Toe against the smartest player of the game in the world will always result in a tie.

In terms of non-videogame games, Challenge is ultimately all there is. Enjoyment is gained from little else; the base interactivity of non-videogame games tends to be moving pieces around a board. Table-top RPGs and high-end miniatures games with grand backstories can buck this trend, but for the most part, non-videogame games derive their enjoyment entirely from the Challenge that their mechanics generate.

In terms of gaming videogames, Challenge is still a very strong aspect. The Situation Model demands it. Though it models interactivity, because most of the dimensions of Challenge are based on factors in the Situation Model, Challenge is an important component of gaming videogames.

After all, what good is gaining Knowledge if the game does not confront you with a Situation in which that Knowledge is required? What good is Experience if the game does not test it? And the only way to test such things is by creating a Situation with Challenge in the appropriate dimensions.

It's like rats in a maze, really. It was discovered that rats running through a maze actually learned how to get around simply by being there. When they started putting food in various locations, the rats were able to find the food much faster than rats who were new to the maze. But nothing indicated to the researchers that the rats learned the maze until they started placing goals in it.

Only when something is Challenged are you certain that it is really there.

However, unlike most non-videogame games, videogame games can create enjoyment from non-Challenging features. The act of interaction, for example, can be enjoyable, as can the videogame's setting or other non-game factors. Even so, much enjoyment can be had by having the player surmount a Challenge.

The difficult, of course, is Pacing. That is, providing the right Challenge at the right place at the right time. As mentioned, some people like sharper pacing curves than others. Despite the fact that Myst sold many units, very few of those buyers actually liked the game. It had a very sharp pacing curve, one that was too sharp for many.

So, what Chris is asking game developers to do is lower the pacing curve. This begs a question though: is there a right pacing curve for a game? A single correct solution for a specific videogame?

No. Ultimately, everyone likes their pacing in a certain way. Some players get bored with games that are too easy. Other players get frustrated with games that get too hard too fast.

What Chris ultimately wants is for game developers to cater to the low-pacing crowd. That's his call, but it need not affect your decisions as a game developer. Higher-paced games are still valid and viable games, from an objective standpoint.

On a personal level, I can't really bring myself to care for the low-pacing crowd. It simply isn't that interesting of a task to design games for them. Their enjoyment tends to stem from the base interaction or other facets of the videogame's construction than from anything involving the game rules themselves.

This musing went kind of wide of its initial purpose, but maybe it's an interesting read none-the-less.

The Digital Game Canon: StarCraft

StarCraft

Perhaps the most definitive RTS game, ever. Consistently considered one of the best games of its genre ever. Played as a professional sport in Korea.

Obviously, Blizzard was doing something right with that one.

Basically, this game is a testament to how to balance a game with multiple distinct sides. Chess and Go are "automatically" balanced because each side has the same pieces and takes the same actions (though some suggest that the first player in Chess has an automatic advantage). StarCraft, by contrast, deals with 3 distinct sides.

The beauty, design-wise, of StarCraft isn't just that it managed the feat of almost perfectly balancing 3 sides. The beauty is that it did so in such disparate ways; that each side is so very distinct from the other and yet still is balanced.

On the small scale, take the first two units that each side gets, for example. One ranged and one melee. However, ranged units (according to the game's mechanics) have an automatic advantage over melee units. By the very nature of how they attack, lots of ranged units can all be attacking a single target, whereas far fewer melee units can gang up on a single target. Therefore, it was designed, on an implementation level, to make the early-game melee units more powerful per cost than ranged units.

Because each side is so distinct, however, they went about it in three different ways. The Protoss Dragoon is powerful, but hideously expensive. For the cost of a Dragoon, you can get anywhere from 2 to 5 melee units (except for Protoss melee units). And sheer numbers makes this a forgone conclusion. And while a Dragoon can kill a Zealot one-on-one, a Dragoon costs a lot more than the Zealot, and it will take more damage per-cost than the Zealot did.

Terran Marines are relatively cheap, and the first Terran unit, and yet two Marines will be mercilessly slaughtered by a single Protoss Zealot. A single Marine cannot hope to survive against a pair of Zerg Zerglings. And a Marine will fall to a Terran Firebat (not quite equivalent in cost, since they require gas to produce, but close enough).

Zerg Hydralisks are often considered the most cost-efficient unit in the game. Even so, a single Firebat will destroy them. And don't even consider sending them one-on-one up against a Zealot (not exactly the same cost, but close enough). And 3 Zerglings will likewise own them.

But look at how each individual melee unit achieves its dominance. The Zealot, despite having it's hugely powerful Psi Blades (16-damage per strike), doesn't win due to its damage output. It attacks far too slow for that. It wins because it can sustain massive quantities of damage. The Dragoon doesn't win in a cost-analysis because it doesn't shoot fast enough to kill the Zealot before it meets out substantial damage. A pair of Marines may not even penetrate the shields of a Zealot before it has its way with them. And a Hyralisk likewise can't kill it fast enough.

The Zergling wins through sheer numbers and awesome damage-over-time output. For the cost of a Dragoon, you can get 5 Zerglings, which deals 25 damage per blow. A Dragoon can kill a Zergling in 2 shots, but that's still plenty of time to get in 50-75 damage. And there's still 4 Zerglings left. A Marine costs 2 Zerglings, and Marines, despite their high rate of fire, can't kill two Zerglings before they exhaust the meager 40 Hp of the Marine. And a Hyralisk costs 3 Zerglings (or 4, depending on how you count gas costs), and they can deal damage much faster than the Hydralisk.

The Firebat wins through its brutal damage output. Though it has the same damage as a Zealot per-attack, its refire rate is far superior. It doesn't have the toughness of a Zealot, but it's not exactly weak either. One-on-one, it's a tossup as to whether a Hydralisk would win, but the costs aren't equal; a Hydra costs 33% more than a Firebat. Two on one, and it's no contest. The Dragoon's cost means that you can get fully two (2.5 by some reckonings) Firebats, and that's enough to tear down the Dragoon's defenses and kill it. And a Marine's damage output can't possibly cope with the Firebat's output.

Each unit is balanced in a way that suggests an overall strategy. They are all balanced, all following the implementation rule, "Melee beats Ranged," but each does it using entirely different mechanics.

And yet, the balance in this case isn't absolute.

Zerglings rely on numbers to be brutally effective. With a line of Dragoons, one long enough so that the Zerglings can't get around it, a problem arises. Only 3-4 Zerglings can attack a single Dragoon, but if the Dragoon line has more Dragoons behind it, then numerous Dragoons can fire at a single Zergling. Even if the costs are kept equal, 4 Dragoons in a line are better than the 20 Zerglings they would go up against. Thus, Zerglings lose their advantage.

Except, Zerglings can be upgraded. With appropriate armor upgrades, a Zergling can require 3 (unupgraded) Dragoon blasts to kill. At the very least, this requires that the Protoss player upgrade the Dragoon's attack to achieve parity again. But Zerglings also have an Adrenal Gland upgrade. This, coupled with their full attack power upgrade, can allow them to more than double their damage output. Thus, one fully-upgraded Zergling becomes two unupgraded Zerglings. To fully counter the attack power upgrade, the Protoss player must upgrade both shields and armor. And nothing can be done to counter the Adrenal Gland upgrade, so the greater rate of attack is still available to the Zergling.

In the end, Zerglings can be made less effective by a Protoss player's actions. But that player must then devote time and resources to this upgrade, thus forcing the Protoss player to slow down.

So, in the early game, melee units are better than ranged units. With time, upgrades, and numbers, however, this changes. And thus, a playthrough of the game changes from moment to moment.

Single-unit tactics eventually become meaningless, because they are easily countered. However, remove 10 of those Zerglings in the Dragoon example and replace them with 3 Hyralisks, and everything goes badly for the Protoss player.

On a large scale, one can see that each side is balanced by it staking out a particular set of player strategies/ideologies. As long as each side remains ideologically distinct, and each side can reasonably exploit a weakness of another's ideology, then the game can maintain a semblance of balance.

The Zerg ideology, for example, is on cheap units and fast expansions. One weakness of this is that these cheap units are not always monetarily efficient compared to others. The Terrans, due to their ability to quickly repair anything they make, can be more efficient in terms of resources. At the higher levels of play, it is said that for a Zerg player to beat a Terran, he has to stay an expansion ahead of the Terran player. The Protoss ideology of quickly moving powerful forces for a strike (the infamous Protoss drops) easily can counters Zerg expansion, simply by quickly eradicating expansions. This forces the Zerg player to substantially defend any expansion, which makes attacking more difficult.

The take-home lesson for StarCraft is about perfecting game balance in entirely unique ways. It's about developing a good set of mechanics that allows for deep gameplay, yet using implementation to maintain balance between different sides in unique ways that exemplify the ideology of each side.

Game Design: Knowing the Unknowable

Earlier I considered the question of what game design was. This was partially in regard to the Situation Model, but it also branched out more into the relationship between what the player sees (the set of possible inputs for a given Situation) and what the game designer creates (a list of rules and so forth that determines what a given Situation is and how the player can act therein).

The secret of game design, the purpose of having a coherent theory of game design in the first place is to answer the following question: how does a particular set of rules create a specific set of Situations that the designer would feel that a player considers interesting and potentially entertaining? That is, a full theory of game design answers the vital question of Chess. How do these seemingly simple rules create such a degree of complexity, depth, and challenge?

However, we may not want to use game design to create "complexity, depth, and challenge." We may want to do something else. Game design can be used to create other emotional reactions (fear, suspense, etc) or to do things we haven't really thought of yet. So a greater, more general formulation of the question is this:

Given a specific goal for a game's design, how do you create the appropriate elements to achieve this goal?

One problem with this question: it may not be answerable.

That being said, the Situation Model is a good tool for answering this question. Using it as a model, a game designer can test bits of gameplay (whether as a thought experiment or as a live prototype) and attempt to experience the game using particular bits of Knowledge and/or Experience. As a design tool, its most useful purpose is making sure that the decision making portion of the game is without pathologies, difficult to the specific degree the designer wants, and has the specific pacing and advancement that the game designer wants.

The Situation Model is a priori knowledge. That is, it is derived entirely from logic based on premises. You could derive the Situation Model before there were videogames, or even before there were games.

As we come to understand the decision making process, we can also see how certain aspects of game design work to create Situations. For example, the primary difference between Chess and Tic-Tac-Toe with regard to decision making depth is that Chess is, thus far, not solved. That is, we do not know the single path that leads to complete victory (or guaranteed stalemate). Tic-Tac-Toe is solved; there is a single best answer which, if taken by both parties, is guaranteed to lead to a tie game.

One of the principle differences is that Chess has a wealth of decisions available to the player from the start. Tic-Tac-Toe, even in its opening move, only really has three (corner, center, side). So, as an ad-hoc rule, one could say that the number of decisions available increases the depth of the game.

Of course, looking at other games can show that this only holds when those decisions are actually important. If some decisions are clearly wrong, then there are fewer actually viable decisions.

This kind of information is an example of a posteriori knowledge. That is, it requires evidence from the world to understand. It requires a degree of experimentation, rather than purely bound to logic.

Until we find an a priori mechanism that can directly answer the fundamental question of game design, until we have a way to know the unknowable, we are going to have to develop rules based on a posteriori knowledge. We're going to have to look at specific instances and develop a theory of how game design becomes what the player plays.

Articles in the "Design Details" section will explore this kind of a posteriori knowledge in an attempt to deduce some kind of theory of game design.

The Digital Game Canon: Riven

Riven: The Sequel to Myst

I know; worst name on Earth. The people at Cyan probably just wanted to call it Riven, but realized that it would be throwing away all the credibility that the name "Myst" had.

The reason for selecting it is that it shows exactly what an adventure game is. It has incredibly clever puzzles, that are so intricately woven into the world that they don't actually feel like puzzles. Except when they do of course, but even then, they're not puzzles so much as elaborate security systems devised by people for reasons that are very apparent.

The beauty of Riven is that it tells you all of this with very little "dialog". It never once breaks kayfabe. Your character never talks, is never seen by you. This isn't even like Half-Life, where you are a particular person (Gordon Freeman) and you can see yourself in mirrors. You can literally imagine yourself there, and just about nothing is ever done that breaks the illusion.

Another thing in Riven's favor is how it gives you information. This game will exercise your Comprehension like no other. You have to learn numbers in the D'ni language. There is one device in the world (suitably in a classroom) that teaches you numbers, but it doesn't teach you it by showing an arabic numeral followed by a D'ni numeral (that would break kayfabe). It teaches you in a more abstract way that requires a certain degree of comprehension for the player to pick up on it. Furthermore, it doesn't teach you everything about D'ni numbers either; you learn 90% of what you need to solve a puzzle, and are expected to deduce the rest. The deduction requires some guess-and-check, but the answer should be fairly obvious for those with enough comprehension, or for those who take enough time to look at the number symbols. It really is a well-crafted puzzle, especially for someone like myself who actually knows a lot about number theory (numbers in non-base-10, etc).

The entire game delivers information visually and auditorially. It also, in true Myst-game fashion, delivers information through a number of journals. However, in most cases, these journals are far enough into the game to where you have already picked up the subtle clues to much of this already in the world that you have seen so far. This is part of the game's genius.

Another piece of genius that should be noted in an academic setting is that the game revolves around solving 2 puzzles. These are world-spanning puzzles that require accumulating vast quantities of information to even find out about them, let alone solve them. The nature of these puzzles should be discussed at length,

Now, the game does have some downsides, despite its genius. The game has one puzzle that is patently unfair. It is a basic Negative Knowledge Pathology. One of the two world-puzzles is broken in that entering the solution to the puzzle is basically impossible. Imagine having a puzzle where the solution is a 5-digit code. Simple enough: find the 5 digits and enter them in the right order, and the door opens. Now imagine that the keypad that you enter them into is not a regular 10-digit keypad, but in fact has 20 keys, where many of the keys are repeats. So there may be 4 copys of the number 5, etc. Except that the 5-digit code does not give you a way to differentiate between number copies, yet it requires that you hit a certain number 5 or a certain number 4 to enter the code correctly. That's what the pathology in this game is; you can absolutely know the code, the digits and the order of entry, but you may not know how to enter them correctly. And the number of viable entries is so vast that sitting there and entering them all would be very boring and utterly destroy the illusion of the game.

The take-home object lesson for this game is puzzle design and worldcraft. And, of course, how easy it is to create a negative knowledge pathology just because someone on your art staff though it would be funny to have a number of symbols look very similar to one another (you'd understand if you knew the puzzle).

The Digital Game Canon, Prologue

Recently, Professor Henry Lowood of Stanford University suggested developing a videogame canon. Such a construct is analogous to the concept of the academic Western canon, which specifies a list of literature, and potentially art and so forth, that are considered significantly influential in Western culture.

I would like to do something similar with videogames. I deride the specifics of Professor Lowood's canon, primarily because of the specifics of game inclusion. From an academic standpoint, "Space War!" gives a player little real information about game design. Academically, Space War! is just not a useful teaching aid. That is not to say that it is a terrible game. But it doesn't show clearly and distinctly a specific tool in a game designers arsenal.

And to me, that is what a canon should do. It should list games that are useful as teaching tools. It should list games that have a clear and convincing object lesson associated with it that shows how a game designer can solve certain problems. And it should be the best example of that solution, not merely the first, which most of those games were.

So, what would I include? You'll find out in this new, ongoing series of articles. Each choice will be explained in detail, covering what needs to be taught in an academic setting (since that's the purpose of the list).

Musing: On PC Games vs. Console Games

In one of my very first posts, I spent some time dealing with the question of videogame genres. Mainly, I said they were useless tools for the purpose of proffering a theory of design. And they are.

But, in a more formal way, what is a genre?

Well, a genre is really a framework. It lays the foundation, providing a number of basic rules for game mechanics.

Board games, in the traditional gaming sense, are a genre. The concept of them is that each player has one or more pieces that represent an entity's location in the game world (the board). And, via some mechanism, players move pieces around or add more or whatever. The framework in this case is player ownership of pieces and that locations on the board have some meaning.

Go and Chess are both board games, yet they are worlds apart. Even their game mechanics are very distinct, yet they both use the same underlying foundation of pieces on a board where the position of these pieces have some meaning.

Contrast Chess and Go with, say, Magic: The Gathering. These have virtually nothing in common besides the fact that they're all games. The genre of M:tG is predicated on cards that create rules, having a hand with cards that are inactive until "played", drawing more cards from a deck, and having cards in a discard pile of some form. This is the trading card game's genre.

So, genre's provide a framework for build game mechanics. Some game mechanics don't work, and others do. What makes a functioning genre is a set of strong mechanics that can be used for multiple disparate kinds of games. Being able to have game experiences as distinct as Go is from Chess.

Super Mario Bros. and Sonic the Hedgehog are both platformers. And yet they are as different from one another as Chess is to Go. Yes, they both involve getting past an obstacle course populated by difficult terrain and simple AI creatures that serve as dangerous obstacles. But they both go about it in entirely different ways.

That being said, above all, there are basically only 2 true genres, which I will call metagenres. These are Mechanics Heavy and Implementation Heavy.

For neither metagenre is the "light" portion of game design unimportant. However, the emphasis, the linchpin upon which the game will or will not work is the one that is "heavy".

The "classic" example of a Mechanics Heavy game is, well, NeverWinter Nights. It is literally built out of game mechanics from something that isn't a videogame: the 3rd edition of the Dungeons&Dragons table-top RPG.

NWN is Mechanics Heavy. It relies upon its game mechanics to create fun. If the D20 system were not interesting, if it did not create interesting choices for the player, then the game itself would not work no matter what else BioWare did to it.

Using a videogame classified as an RPG as a counter-example, we have, well, any Final Fantasy game. This game is very focused on Implementation. How much experience the player gets at a particular time. Which monsters the player faces, assuming the player has X abilities at that time. What matters in a FF game, what determines how good its gameplay is, depends greatly on exactly how the battles are put together. Which monsters are encountered when.

These issues matter in NWN, but not to nearly as great an extent. Likewise, the combat system of a FF game matters, but never to the degree that it does in NWN, if for no other reason than the fact that the system permeates every aspect of the game. Options open up for you if you have certain skills, or items or whatever.

It's funny. For reasons I haven't quite figured out, PC games tend to be Mechanics Heavy, while console games tend to be Implementation Heavy.

Just think about the great PC games. For the most part, they're Mechanics Heavy. The Sims, StarCraft, StarControl 2, Rome: Total War, pretty much every PC RPG, Civilization. Indeed, PCs have entire genres that are Mechanics Heavy: RTSs, Civ-style games, RPGs, etc.

Noticably absent from this list: FPS games. While mechanics do matter, particularly for their multiplayer aspects, the quality of the single player experience is derived from the implementation more than the mechanics. Why are they focused on PCs then? Controls. That's it. With dual-analog becoming more acceptable, you're seeing these games take the leap onto consoles.

Which is where they belong. Right alongside action/adventures, platformers, 3rd-person shooters, and the other host of console gaming genres of note.

How did this happen?

Well, part of it is somewhat historical. Consoles have been limited in what mechanics they could provide. First by the basic hardware resources (CPU power and memory), and later by what could be expressed by their controls. This forced console developers to focus their energies where they could: implementations. Mechanics had to be fairly simple, so it was the implementation, level design and so forth, that had to take to the fore.

By contrast, PCs have memory and performance available to them. What they had preventing them from exploring implementation was not hardware.

Another part of it is cultural. The PC gaming market has been ruled by, well, geeks. People who absolutely love minutiae and obsess over it. They are intrigued by interesting mechanics, and they do not like being told by some implementation (level design or whatever) that they cannot try something. Broad mechanics with fairly light implementations cater to these people. Not to mention, the first PC games were made by geeks for geeks.

By contrast, console gaming has lived a different life. Since the demise of Atari, console gaming has been focused largely in Asia, Japan in particular. There is a cultural emphasis on what would be considered focused experiences without the minutiae of clever game mechanics. You can see it with their non-gaming entertainment like anime and manga (particularly in the willingness to break with established canon if it serves the story), and the culture spills over into their gameplay. The mechanics are seen as a means to an end; a way to create the possibility of compelling gameplay.

So, there it is: the fundamental difference in PC games and Console games. One favors game mechanics, while the other favors game implementation.

Game Design: What are we Designing?

Note: This is (probably) the only article where I will actually distinguish the term "game" from "videogame". Every other place will use these as synonyms, except when we are actually discussing the game-like character. In those cases, I will use specific language to distinguish them. Unless the context suggests otherwise, you can assume that the term "game" means "videogame".

More and more, we hear about things called "non-games." Things like The Sims, Second Life, Brain Age, etc. There are basically two definitions of non-games: videogames for people who aren't traditional gamers and videogames that aren't games. So, let's discuss what it is we're talking about.

First, let's define the term videogame. A videogame is an piece of software or hardware whose primary designed purpose is to elicit some form of enjoyment or entertainment. This separates videogame software from, say, Word or Photoshop. Plenty of artists have fun with Photoshop, but it's primary designed purpose is to empower the user with regard to editing images.

Now the phrase "primary designed purpose" is key. Why? Because Mario Paint is a videogame while Photoshop isn't. And this is not simply because Mario Paint came out on a console and Photoshop didn't. Eletroplankton is a videogame, despite the fact that it could be considered a strange combination of Photoshop and a sound synthesizer.

The reason Mario Paint is a game is because its user interface for editing images is designed for the purpose of making it fun, not useful. You can do things of value in Mario Paint, but the main purpose is to fool around, stamp out some nifty animation with Mario characters, and so forth. Maybe if you really get into it, you might try something serious, but its tools are really too simplified for that.

Microsoft Paint also has simplified tools. The primary difference there is that Paint's simplification is not designed so much for entertainment, but for ease of implementation. For just about every one of Paint's features, there is an equivalent Windows graphics API call. In short, Paint is really a thin user interface over the Windows graphics API.

Photoshop is designed to give the user powerful features for editing an image. This is its primary purpose. Whatever enjoyment comes out of using Photoshop is provided by the user's enjoyment of creating art, not the designed intent of the Photoshop developers. They merely provide what is useful towards the end of creating images.

So, a videogame is merely an electronic "device", hardware as in the earliest days of arcades, or software as in modern times, that is designed for the purpose of being entertaining.

However, that doesn't deal with the Game vs. Non-Game distinction.

Personally, the distinction between the two comes down to the traditional definition of the term "game".

What is a game? Well, a game is a set of rules for interacting with something and a set of objective conditions that determine when the game ends and who won, if anyone. This definition covers everything from Chess to Tic-Tac-Toe to Super Mario Bros. So, what doesn't it cover?

The Sims, for starters. SimCity as well. Will Wright famously and rightly states that these are not games; they're toys. A toy is something that has a set of rules for interacting. You can bounce a ball off of objects, but you cannot turn it inside out (well, you can, but it is a different object now) That is, a game is a toy that has explicit victory conditions.

Brain Age is a game. It is a game because it has an explicit score, and you know when you've won, because it tells you. Old-school arcade games that measure success by score are games. Competitive FPS's are games.

Note that the definitions of "game" and "videogame" are not related at all. There were games before videogames, and there are videogames that are not games. I use the term "videogame" as opposed to something that doesn't use the root word "game" simply because it's more widely know. I could say, "Interactive Entertainment" or something of that nature, but it's difficult to know how that is different from table-top Chess.

So what is the difference between a game videogame and a non-game videogame? Gaming videogames are about one thing: winning. The Interactive Loop is used to improve the player's skills and provide appropriate challenge. Mechanisms of design create interesting Situations for the player to overcome. And the design gives the player a way to tell how well they're doing and whether they "win". But even victory is secondary to the enjoyment gained from the Situation-to-Situation momentum of playing the game.

Non-gaming videogames use the Interactive Loop for some other purpose. Simulation-type videogames use the loop for the purpose of modeling a simulation, whether based on real principles or not. What matters in those videogames is how interesting the simulation is and that the rules of the simulation create interesting situations. These too have a degree of Pacing, though in their case, it is not always based on challenge; it depends on what the player chooses to try to achieve with the simulation. The quality of a simulation videogame is judged based on how interesting the situations that it naturally creates are, and how these situations flow one into the next, much like for gaming videogames.

There is a great deal of potential for finding other uses for the Interactive Loop. For example, Electroplankton uses the loop, not specifically to create a simulation, but to create audiovisual patterns. There is no victory; it is simply about the player creating an interesting audiovisual effect. Mario Paint does something similar, though in a more traditional way. Some videogames have even tried to deliver narrative content through the Interactive Loop, though with limited success.

Note that these are not hard-and-fast categories. Simulation-type videogames can have substantial elements of gaming properties, and vice versa. We will deal with this later as we look more in-depth at game design.

As for videogames for non-traditional gamers, the distinction matters, but not from a design point of view. Granted, videogames of this type tend to have slower pacing models and generally less complexity in terms of challenge and/or fewer dimensions of challenge. Their purpose tends to be introductory in nature, which is a reasonable goal.