GDC 2010: Design in Detail V


The second way to develop a sense of balance about paper designs is to look for anticipation. (Anticipation really isn’t the right word for it, maybe “Imperfect Predictability”?) If you make players guess, they won’t see the point and will quit. If you don’t give them a chance, they will feel controlled and quit. Balance means probable, but not inevitable, future events. This allows the player to anticipate them.


Don’t your players into ridiculous movie villains.


David Sirlin (sirlin.net) is a SF Champion and a game designer (and just happened to be in the audience when I gave this talk at GDC.) He calls this concept Yomi.
In an action game like Halo you don’t want players to engage in this kind of second-guessing. It will paralyze them from acting and end up in random guessing. The Sniper Rifle has one purpose; you know what someone with a sniper rifle is going to do. The role prevents you from guessing by allowing them to anticipate what is going to happen. If they are expecting an event, they can process it more quickly and follow the action better.


Successfully sniping confers no benefits. As designers, we throw around the term “Feedback Loop” a lot, but they are not always good because they lead to a game being overly predictable. Anticipation requires uncertainty, and feedback loops work against that.


The best thing about roles is that they help you keep things manageable by breaking the design into workable parts.


If you are using roles, make sure players always have other options. The Sniper Rifle is never your only option, so the entire balance never rests on one weapon. By using multiple gameplay channels you reduce the difficulty of your balance problem.


If you break up the balance into groups that do not require cross-balancing your problem becomes simpler. I won’t say that monolithic is always bad, just harder.


The Sniper Rifle is not on every map. This limits the number of possible interactions that need to remain balanced.


Imagine somebody is holding a gun to your head… There is too much to do, what are you going to cut! What are you going to do? How can you get control of your scope? By making the hard choices…


What are the hard choices in the paper design pass? Which mechanics will you emphasize? How will you engage the player’s imagination?


Producers, please insert your fingers in your ears at this time. Some of the best advice I ever got was “Once you are done, cut half” and I have never regretted doing this. I’m not going to say “Kill your babies” Now that I am going to be a dad, the term doesn’t seem appropriate anymore. How about “Put your babies up for adoption”?

To be continued…

GDC 2010: Design in Detail IV


How do you develop your sense of balance for paper designs? It can be done, you can look at a paper design and have an intuition about how it will work. You are looking for the role, and for a couple key factors that are the results of the role.


The first thing you are looking for is to make sure the paper design is neither too simple, nor too complex. If your paper design is one sentence long, it is probably too simple. People are going to reach the limitations quickly and stop playing. (Remember, balance is longevity)

If it is more than a page long, it is likely too complex. People will never reach their comfort level, they will stop playing because they can’t understand what is happening. Balance is a barely manageable number of choices. (I bet I end up writing a post on this slide at some point.)


This is where roles come in because they provide depth without increasing complexity.

The Sniper Rifle is the best weapon in some situations. The Sniper Rifle has a clear role, times and situations where it is the best. The payoff for using the Sniper Rifle is different depending on what situation you are in. This is good, because game theory tells us that if all the possible strategies have the same payoff, players will pick randomly. As game designers we want to avoid choices that don’t ultimately matter.

Roles are also good because they cause asymmetry, which demand movement. There are incentives to move from one strategy to another depending on the situation.


One of the tropes of the design community… Rock, Paper, Scissors. But it’s a terrible game!!! Every choice has the same payoffs, so you pick randomly. There is no player agency if their choice is meaningless.

It’s a cool shirt, though (www.noisebot.com)

This was easily the most controversial slide in this talk. Several people took issue with the fact that RPS is a bad game because many journalists and designers improperly use it to describe a situation where one unit strictly dominates another, like in a good RTS. But imagine a RTS game where you could only pick one unit, you had to pick it before the game started, and if you picked wrong you couldn’t possibly win, It’d be a bad game!
The reason a RTS game works is because it isn’t RPS:
– You can play mixed strategies (choose more than one kind of unit)
– Strategies have different costs to play (tanks cost more than barbarians)
– You can change strategies mid-game
– Strategies rarely have an all-or-nothing payoff (10 Air units can usually kill 1 Anti-air unit)

So I am not using RPS in the casual sense of “a game with counter-strategies” but as defined in game theory; Hopefully that clears things up a bit.

I also got a lot of people saying, “RPS is the foundation of Street Fighter!” This is true, somewhat, more than the RTS case, anyway. but imagine a turn-based game of SF where the first hit wins the match. Again, a bad game.

The reason SF works is that it is also not really RPS:
-SF is a series of RPS interactions, so things like reputation and anticipation come in.
-It is played very quickly, so low level decision making and muscle memory determine your strategy more than choices, so it isn’t truly random.
-And even with that, most non-expert players tend to “button-mash” which is a great example of “random strategy”

Believe me, I am not trying to insult RTS games or SF (or even Ro Sham Bo Tournament Champions) but to encourage designers to see how roles lead to non-equal payoffs, and therefore avoid random strategies.


“Rock, Paper, Scissors, Lizard, Spock” is even worse game design. (This game is from the show “The Big-Bang Theory”) It looks more interesting, but it isn’t; it is just more complicated. It will still reduce to equal payoffs and random play.


This doesn’t even make sense! (Interesting note: Halo 1 was this close to shipping without a Shotgun, which makes even less sense…)


Avoid strict dominance…Wait, what is strict dominance?


Who picked the Health Potion? The single-use health replenisher you can buy for 30 rupees?
Who picked the Piece of Heart? The totally unique health-extender you can never buy?

Right, everyone picks the Piece of Heart. (If you didn’t, it’s ok, you were probably eight.)


Iterative deletion means you remove all the dominated strategies, then you remove all the strategies that were only good against those strategies. If you cut the Tank, cut the Anti-Tank Mine. Often when you are making cuts in the final stages of production, it seems like a good idea to cut a little bit from a lot of places, but it is uaully better to cut an entire game mechanic and all of the game elements that use it. Otherwise you end up with several systems that feel like they have missing pieces, rather than a single system that is entirely absent.


After GDC I got challenged to come with an example like Rock, Paper, Scissors that is good game design, so I invented Pirates, Ninjas, Sharks. Each has their own strengths. Ninjas are better at night, but Sharks always win in the water, while Pirates come in crews, etc. A good game is one that you can argue about forever.

[Continued]

GDC 2010: Design in Detail III


The first step in Halo 3 was the paper design.


This is one of about 4 slides for Producers.

The Paper Design should happen in Pre-production. You need to do paper designs first so you don’t have 40 artists sitting around while you do it. On the other hand, if you leave it too early, you are going to waste lots of time later. So as producers, you need to find creative ways to give us room in this stage.

Every gameplay object should get a Paper Design. Don’t let Designers hand wave, because we are great at it! If we can’t write it down it means we haven’t figured it out. Lack of design discipline is a huge threat to your project. On the other hand, if you have a designer that has proven his discipline, then trust his paper design. Take off your design hat before you mess up the game!


Nobody has ever seen this outside of Bungie. It’s the original paper design for the Halo 1 Sniper Rifle. It is embarrassingly simple, but it is better to be simple than overly complicated.


Here’s the important things to note:
Some specifics are wrong. That’s because at some point the paper design is abandoned in favor of the existing object in the game.
Some mechanics are unclear. That’s because it is often difficult to capture an entire system inside a single paper design.
Many details are missing. A paper design should only include crucial or unique information, not every trivial detail.
It’s very flawed as a spec, but one thing comes through, the Role of the weapon.


So now let’s look at Halo 3’s paper design. It’s a lot more detailed. But it is still pretty abstract and the role is even more clear. (It ought to be, it was the third iteration!)
It might seem like a waste of time to do a revised paper design since it was essentially the same weapon as the first two games. But it is still important to capture and communicate the vision, because not everyone will have the same understanding of what was important in the previous versions.


“Role: Long-range instant-kill sniper rifle, but reloading makes it difficult to use”
The Role is even more clearly called out. Someone pointed out that Halo has two sniper rifles, which seems to violate the “one weapon per role” rule. Truthfully, they are right, but the missions required enemy snipers using an alien weapon. But, even in that case it is a good idea to give them unique gameplay; that’s why this paper design refers to the fact that the human sniper rifle reloads, instead of overheating.


I felt like this slide failed to capture what is really important about writing a paper design, so I wrote a much more detailed post on the topic.

[Continued]

GDC 2010: Design in Detail II


In order to develop a sense of balance, you need to understand how your brain works. You have an Orbito-Frontal Cortex; It’s called that because it is located behind your eyes, but it’s really your Gut.  When you learn something new, it goes through a process where it builds a model of the world and makes predictions about that model.  If it is right, it releases Dopamine, which cements the model a little bit.

If you are a designer, you need to familiarize yourself with how this process feels, because your ultimate goal should be to get the game inside your head.  You want the model in your gut and the game in the world to be the same.  You should be able to predict how the game will play in a given situation before actually picking up the controller.


Ok, back to Halo 2.  We had to patch, even though we didn’t want to.  Patches are risky and expensive.  Luckily we had network bugs, so we were going to have to patch anyway.  (I’m not sure we would have gotten to patch Halo 2 strictly for balance changes; I’m glad we didn’t find out.)

Choosing what to patch was harder.  You want to tweak everything, but you can’t because then testing gets out of hand.  Games that have the ability to easily change the gameplay often over-patch fopr precisely this reason.

Choosing what NOT to patch was hardest.  We didn’t change the Sniper Rifle because it was right below the line of what we could safely re-balance

Which brings me to my final theme:  Make the hard choices.  Balancing is hard because it requires you to do things you don’t want to.  And it is tricky because there are so many ways to confuse or talk yourself out doing it properly.  But the worst thing you can do is leave the decision up to chance because you can’t make a tough call.


Why are these choices hard?  Again, the answer is your brain.  You also have a Pre-Frontal Cortex.  It’s called that because… Who knows?  We call it your brain.

It is a poor tool, but it’s what we have.  You can’t reason out everything, in fact you can’t reason out very much at all.  There are so many ways that your logical mind has to trick you.  You must confine yourself to reason on the detail scale.  You just can’t hold enough factual information in your brain to make rational decisions about very complex situations.


Radiolab is a great show on New York Public Radio.  They have a podcast, you should subscribe!  In an episode called “Choice” they describe this experiment where psychologists give people a number to memorize, 2 digits to 10 digits.  Then they send them to another room to repeat their number.  On the way, they have someone interrupt them (All good psychological tests are about fooling the subjects) and ask them if they want an Apple or some Cake.

The people with short numbers pick Apples at a high rate; Apples are better for you, fewer calories, watch your waistline.  Those trying to remember longer numbers more often choose Cake.  They are so busy with numbers, they make the decision emotionally.

That’s right, 7-10 numbers are enough to completely fill your rational brain!  My high school calculator had more horsepower than that!

So when you have to think rationally, think about details or you will get hopelessly lost.  And fat.


Ok, here are the four themes of my talk:
– Balance is longevity
– Balance in passes
– Develop your sense of balance
– Make the hard choices

I am going to use these themes to explore the Detail.  Now let’s get to the Sniper Rifle!

[Continue]

GDC 2010: Design in Detail


Ok, so when I gave this talk at GDC I didn’t have time to finish, even though I was talking very fast.  I did better when I gave it at Blizzard, until my voice ran out and I could barely speak.  So I probably should have cut some ideas out and saved them for this year.

I do see the irony of failing to trim a talk that advices designers to drastically reduce the scope of their game as early as possible.  But to me, the value of GDC has always been that it makes me think about my own problems from a different perspective and inspires new ideas as I listen.  So I wanted to cram as much idea-fodder into the talk as possible, not produce a fluid, polished experience.


I did not make the call on the Pistol, I didn’t even know about that call, it was made directly to the cache file after everything was supposed to be locked down, in fact… but I’m not bitter about it.  I did decide to give the BR some spread, which has been the topic of much debate.  Luckily Reach has been even more controversial, so nobody remembers it anymore.  It’s interesting that every single Halo game has had major controversy over the MP starting weapon, I bet you could write an interesting talk about that.


In 2009 I was at the Art Institute of Chicago visiting my family.  (I grew up in and around Chicago.)  I saw one of the most famous paintings of all time and took a picture of it with my phone.  I actually did have the idea for this talk at exactly that moment, at least vaguely.  Any guesses as to the painting?


It’s “A Sunday Afternoon on the Island of La Grhand Zhot” by Zhorzh Soo-rah (I really wanted to pronounce his name right…heh)  This painting inspired my talk (and its very long title)  Still don’t recognize it?  Here it is from a little farther back.


(I showed you the part in the lower right by the monkey)
This painting isn’t famous for how it looks, or what it shows, but how it was made.


Seurat lived in the 1800’s.  He was very interested in how we perceive color.  Scientists were just discovering that what we see as one color is actually a mixture of different colored light.  To demonstrate this fact, he invented Pointillism, the artistic process of using tiny dots of basic colors to produce an image.  The same way your printer does.

There is a really great play called Sunday in the Park with George that I recommend you see if you are interested in learning more.  You can skip the final act, though.

So I started thinking…  What happens if we take Halo 3 and break it into it’s tiny details…


And analyze just one of them.  Take one tiny Decision, and explore it exhaustively.  Specifically, the time between shots for the sniper rifle.  (I had a lot of fun putting together the pictures for this slide deck.  I never tried to pointilize a screenshot before.)


So here is the actual title of my talk.

If you have been to GDC, you know that most of the talks are too broad to be really interesting.  It doesn’t get much more specific than this!  (Of course, I took this narrow topic and used it to explore lots of subjects and theories, but still…)


My opinions may not represent Bungie management.  In fact, I know they don’t.  (If I only knew the irony of that statement at the time!)  My opinions may not represent reality; this is the past as I remember it, but as we will find out, brains are not reliable.  All examples, even negative ones, are from good games.  I tried to pick on games that everyone knows are great, to avoid controversy.

This talk was really hard to write! Really hard. The more specific the topic, the more there is to say.  It ballooned to almost 300 slides, editing took forever (and it turns out I still didn’t edit it down enough!)


First, some context from Halo 2.


Halo 2 wasn’t just popular, it was popular for years and the Sniper Rifle remained balanced the whole time.  It never needed to be changed, limited, banned, it was still fun.

This can give us a practical definition of Balance:  Balance is Longevity.


(X= 3, I told them my talk would appeal to Engineers!)

Balancing an equation is a process.  But game balance is a state that either exists or it doesn’t.


The 4th rule of Jenga makes it clear (say it with me):

4. Your turn ends 10 seconds after you stack your block

It isn’t balanced unless it lasts.  (I bet you didn’t expect to see a Jenga reference!)


There have been other talks about Halo 2’s crunch; I’m not going to re-hash them.  My really quick personal post-mortem:  Don’t set yourself up to try and fix bugs in the Tutorial and balance the Weapons at the same time, It’s not going to work.  At least not without wrecking your personal life.

Production is always worried about a repeat.  (As you can tell during this talk, Production and I have a love-hate thing going.  It is mostly a joke, but Deisgn and Production have very different goals and the game is only going to work if they cooperate.)  They were always asking me when I am going to be done, so I invented the Balancer’s Paradox.

Balancer’s Paradox
– I can’t balance the Sniper Rifle damage until we set the Player’s health
– I can’t balance the player’s health until we know the engagement distance
– I can’t balance the engagement distance until we set the Sniper Rifle damage.

But after using this for awhile, I actually had to invent a solution…  Balance in passes.  The Sniper Rifle always has to be balanced! You could ship at any time!  So you keep it balanced all the time.  But there’s balanced, and then there’s balanced…


At the end of each pass, the game is balanced to a certain level.  Once a game is balanced to that level, do not backtrack.  Basically, what this means is that if you have balanced the strength of a game element, don’t make it weaker in order to limit the roles of that element.  Unless you have to, of course, in whic case it will impact the schedule so you need to let Production know.

Halo 3’s Balance Passes are listed here.  I think they would work for most games.  They match with stages of game development and I’ll go over them in more detail later.


Remember: Balance is Longevity.  And we could tell by playing it that it wasn’t going to last.  We all had the same feeling and we didn’t really doubt it.  But how did we know?  We had developed our sense of balance.


In Outliers, Malcolm Gladwell lays out his 10,000 hour rule.  This makes me the world’s only expert in trying to balance the Halo Sniper Rifle.  Sort of a narrow expertise, I admit.

Niels Bohr offers this definition of an expert.  This also makes me the world’s foremost expert in trying to balance the Halo Sniper Rifle (and in Driving too Fast for Conditions.)

But what are time and mistakes? They are just experience.  So why is experience so much more important to being an expert than training, knowledge or talent?  Because of how your brain works.

[Continue]

Balance Pass: Role

One of the most important reasons to balance in passes is a practical one.  The earlier an element is cut from the game, the more resources are available to the remaining elements.  A good designer will always have many more ideas than they could implement, and it is tempting to push all of the ideas forward until the schedule demands cuts, but it is almost always better to trim early and avoid wasted effort.  That is the primary goal of the Role balance pass.

Please pass the roles

 

Timing

Post Pre-Production.  This is the first balance pass, and it happens immediately after pre-production.  During pre-production, design should focus entirely on generating ideas and prototyping systems that are not fully understood.  Prematurely worrying about schedule or scope can strain the creative process, preventing the design team from cycling through the bad ideas that eventually lead to good ones.  There are many schedule pressures to keep this brainstorming stage short, but the costs of entering production without completing this process are often much greater.  Changes made in pre-production are much cheaper than the ones that happen after resources have been committed to a bad idea.

A Paper Design for Every Element.  The designer’s primary responsibility in pre-production is to make sure that every single game element has a paper design.  It is far too easy for a designer to be vague and only fuzzily understand how a given element will work.  Taking the time to think through and write out a paper design takes discipline, but will allow the designer and the rest of the team to proceed with more confidence, and minimize expensive surprises.

Defining a Role.  The most important part the paper design is a description of the role that the element will play in the game.  Without a clear idea of what an element is for, no amount of detail will be sufficient to describe it.  On the other hand, sometimes a role so completely defines an element, that no more information is needed.  Roles can be simple:  “A long-range instant-kill sniper rifle.”  Or more nuanced:  “An enemy character that serves as the backbone of an encounter, uses every available weapon and vehicle, and provides a foil for the player to overcome.”  But they should always be singular and establish a bar for what is required for the final in-game asset.

Methods

Even though they do not exist in the game, and cannot be played yet, once each game element has a paper design and a role they can begin to be balanced.

Remove Overlap.  The most useful way to balance game elements at this stage is to make sure they are not filling the same roles.  Two elements that have the same role are a waste of resources.  Either they will be identical except for cosmetic differences, in which case they will confuse players by offering a choice with no meaningful difference.  Or one will strictly dominate the other and be better in every situation, making the weaker one redundant.  Or you will be forced to spend valuable time differentiating and balancing them, without actually increasing the player’s options.

Often, when elements have the same role, they can be merged into a single, stronger idea.  Other times elements may appear to have the same role, but further exploration will show that they are indeed different, which provides a deeper understanding of how they will function in the game.  Regardless, by the end of this balancing pass, every element should have a unique role.

Don’t Overlook Roles.  Often the brainstorming process is very chaotic and undirected.  We never know when a good idea will occur to us!  It is easy to overlook common roles or miss very niche ones.  This balance pass is a good opportunity to take stock of all of the game elements and look for any holes.  For example, if the player will be fighting against snipers, but has no long-range weapon in his arsenal, he will feel like he is unfairly limited, that part of the game is missing.

The importance of  filling every necessary role is precisely why the weapon selection for most shooters ends up virtually identical.  Most shooters require an accurate long-range weapon, a powerful short-range weapon, a weapon that is good against multiple opponents, etc.  So most shooters end up with a sniper rifle, a shotgun, an smg, etc.  Players may complain about the lack of originality, but not as much as they would complain about the lack of a shotgun!

Limit the Number of Roles.  The final step to this balance pass is to get a feel for the scope of the game and the overall number of elements that will be required.  Determine what the absolute minimum number of elements are absolutely necessary to make a functional game.  (Note: Never tell Production this number!)  If the total is more than 20-30% over the minimum amount, there are probably too many elements.  It is a good idea to have a buffer, in case certain elements don’t work or are harder than anticipated.  But the fewer elements that make it through this pass, the more polished the remaining elements will be, the easier it will be for players to understand and use them all, and the tighter the gameplay will be.

This is how I Rolls

Balance the Rolls?

Results

Confidence.  As a result of this balance pass, the entire team will feel more confident in the scope of the game and the quality of the design.  A disciplined design is less likely to have to be changed, wasting the time and effort of the artists and programmers.  It will also make the rest of the team less resistant to changes that do need to be made, because they will know the designers took every precaution to avoid them.

Depth.  Balancing the roles requires a sophisticated understanding of what each game element is for and how they will interact in the final game.  By reaching that understanding early, every subsequent decision will be able to support that role, deepening it and creating complex connections between elements.  The art, sound, effects and other aspects can reenforce this role, making it crystal clear to the player.

Manageability and Flexibility.  When overlapping or unimportant roles are removed, the following balancing passes become much easier.  Not only will there be fewer elements to balance, but they will not come into conflict as often because they will have distinct uses.  Also, a disciplined balance pass will leave some room in the schedule for the great ideas that inevitably come up later in the project.



Case Study: Tribes

Previously, we have explored how the community balances a game, sometimes despite the developer’s best intentions.  Tribes is a great example of how the community not only determines how the game is ultimately played, but often decides the path of future development.

Tribes shipped in 1998 to a fair amount of critical and commercial success.  It featured large multiplayer battles on open terrain that were beyond anything that had been seen before.  Players could choose between three armor classes (Heavy, Medium and Light), pilot vehicles, plant bases, purchase weapons and equipment… it even had jetpacks!  It also had one very significant bug, an unintended side-effect of the physics system known as “skiing”.

That flag is on fire because it's sweet

Go Zebra Tribe!

By tapping the jump button while descending a hill, players could exploit this physics bug to accelerate to an incredible speed.  Combining this technique with the jetpack would allow players to quickly cross even the largest maps, much faster than the designers anticipated.  This worked even with heavy armor, meaning there was little incentive to choose the lighter, more agile classes.  It was faster than vehicles, making them redundant.  Since most of the weapons did not have instant travel projectiles, it became almost impossible to hit anyone outdoors.  Nearly every aspect of the gameplay was affected.

In a short time, the game balance was totally wrecked… and the players loved it!  They invented new strategies, found new ways of attacking bases, used old weapons in new ways.  They became experts in using another physics bug called “body blocking” to physically bar enemies from escaping with their flag.  The chaingun, a weapon that had been scorned, became their weapon of choice because it fired one of the few projectiles fast enough to hit a skiing player.  They re-balanced the game around this new game mechanic.

Speaking of unexpected effects...

The Tribe has spoken.

The developers attempted to fix the game with a patch, but the community rejected it.  By that point, everyone who did not like the effect of skiing had already left the community.  The remaining players where those that thought it was fun.  Unfortunately, this smaller community was the only audience for a sequel, so the development team were forced to cater to them.  Tribes 2 not only included an “official” version of skiing, but even explicitly taught new players how to do it!



Takeaways:

  1. Don’t just test for bugs, but to ensure the gameplay experience is the one the designers intended.
  2. The ultimate balance of a game lies in the hands of the community that plays it.
  3. Fun activities are rare, and when we find one (even as the result of a bug) we ought to embrace it.

Balancing in Passes

As with any creative endeavor, balancing a game is a difficult process to predict, and even more difficult to schedule.  To alleviate some of the pressure, game designers invented a circular excuse known as The Balancer’s Paradox:

  • Balance cannot happen until the end.  Every game element and knob impacts the balance, so until they are all present and functional the game cannot be balanced (and it won’t be fun.)
  • Balance cannot wait until the end.  Until the game is balanced it is not clear what elements are actually necessary or what knobs will be needed to balance them, so a complete list cannot be finished until the game is balanced.

This is very effective at eluding production demands, but unfortunately to ship the game the designer must actually find a way around this quandry.  The best solution is to balance in passes.  At several points during development, attempt to balance the elements that exist, using the knobs that are available.  The resulting balance will not have much longevity, but it should give you enough information to prioritize the remaining elements and knobs.

There are several crucial points at which a designer should stop and do a balance pass:

Pass Stage of Development Goal
Role The paper designs for all the game elements are finished A manageable number of roles with no overlap
Flow The elements can be tried in the game Elements allow the player to achieve flow
Strengths The game rules work well enough that elements can be tested against each other Elements that are strong enough to be useful
Limits Playtesters begin to abuse elements by using them outside their role Limit every element to its intended purpose
Exceptions The balance is stable enough for small exceptions to appear Eliminate bugs, unexpected uses and local imbalances
Perceptions The balance is polished, but the assets are not yet final Support the balance with matching effects, sounds, animations, etc.

Tripping over the Starting Line

Running is risky.  Your center of mass is so far in front of your feet that you are constantly falling forward, catching yourself with each stride.  You appear to be in control and stable, but in reality you are always one misstep away from catastrophic failure.  (Thoughts like this are why game designers are rarely world-class sprinters.)

QWOP

Ready!

During development, a game can appear to be balanced, but is actually just being carried along by momentum; the instability is masked by constant change.  Releasing the game at this point is like tying a runner’s shoelaces together.

QWOP

Set!

When the designers cede control to the community, they quickly find the truly balanced state.  Unfortunately this often results in a degenerate or random experience where entire gameplay modes are untouched, fundamental mechanics no longer have an impact, and usually the game becomes too simplified to remain interesting.  Even worse, developers are often forced to incorporate the broken mechanic into a sequel or risk alienating their fan community.

QWOP

Trip!

How does this happen?  Often it is a result of a flaw in the development process.

Unenforced Conventions

Early in development, when the game is being prototyped, it seems inefficient to rigorously encode the game mechanics.  It is easier to just ask playtesters to refrain from using certain tactics, ignore logical loopholes, and pretend the game works in a different way than it actually does.  After all, the playtesters are usually on the development team, and the prototype changes faster than the code can be updated.

The problem comes when these conventions become so firmly established that the designers start making assumptions about what the community will do based on those (false) expectations.  When the game is released, the community does not respect conventions, they will exploit any tactic or loophole the game allows, ultimately breaking the balance.

Isolated Game Systems

A common production tool is to organize features into prioritized lists, with the understanding that everything below a certain line has a chance of being cut.  This encourages designers to create isolated game mechanics, parallel systems that do not interact with one another, so that the inevitable cuts have less impact on the surviving mechanics.  These layers are frequently worked on by different designers with different goals and ideas about what the game should be.

This leads to the situation where game systems are individually balanced, but in differing, or even conflicting ways.  The progression mechanics that keeps player invested in the community might break the competitive multiplayer game.  Or large sections of an environment may go unused because of the way the mission objectives are placed.  Usually, the most poorly balanced aspects of the game drag down the other systems, leveling any interesting nuance they might have had.

Ignoring the Skill Zenith

Designers are rarely as good at the games they develop as the people that play them.  (They tend to spend more time building them than mastering them.)  It is often their ability to sympathize with the “average” player that makes them good at their jobs.  Unfortunately, this means that they have a blind spot and cannot always predict how the game will be played at the very highest level of skill.

Nothing wrecks game balance as fast as a community that is more skillful than the developers anticipated.  Actions that were meant to be impossible or happen only through luck become fundamental to the game.  The community is split between those that can execute the “impossible” tactic and those that cannot, and are no longer competitive.

No game ships with flawless balance, but by avoiding these pitfalls your game community may last long enough for you to tweak it.

Balance by Attrition

In classical physics, Newton’s Second Law of Thermodynamics states that over time, differences in temperature, pressure, and energy even out across an isolated physical system.  If you leave a fresh cup of coffee on your desk in the morning, by the afternoon the coffee will be much colder and the room will be slightly warmer, leaving them both at the same temperature.  (Most game designers aren’t physicists, so we are constantly surprised by mouthfuls of disgusting lukewarm dreck.)

A similar law holds for multiplayer games.  Immediately after release they are in a very energetic state as the community tries every game mode, tests every tactic, exhausts every possibility.  (Like a human Monte Carlo simulation.)  Gradually the community activity slows down.  Certain gametypes become ghost towns.  Entire classes, tech trees and strategic choices are dismissed.  Carefully crafted game mechanics are ignored.  Map rotations shrink to a few prefered maps.

de_dust

Or maybe just one

Ultimately every game is balanced by the community through this pruning process.  Ideally the surviving experience is close to what the developer intended, but they will not stop until they reach one of the following stable states:

1.  There is no game left. 

Unfortunately, once the players remove the broken game mechanics, unfinished features, buggy networking and superfluous options from some games, there is nothing to play anymore.

Potential Community:  The immediate families of the dev team and game reviewers looking for easy targets.

2.  The game outcome is random.

Many games have random factors with enough impact that they determine the course of a match.  (The first player always wins Tic-Tac-Toe.)  Other games do not allow players to adapt or execute more skillfully, so the winner is determined by the game’s initial conditions.  (All the strategies in Rock-Paper-Scissors have the same chance of winning.)  Some games have an inherent imbalance that cannot be overcome, so your chance of winning is determined by who you are playing against.  (Games with a severe host advantage favor players with good connections.)  No matter what the cause, these games are essentially decided by dice rolls.

Potential Community:  New or non-competitive players who want an equal chance of winning.

3.The game is determined only by skill.

If the players discover a single dominant strategy, or if a superior strategic choice can be overcome by faster reflexes or more skillful execution, the game will be simplified to a straightforward contest of skill.  (The only strategy in the 100 yard dash is “run faster.”)  Any subtle game mechanics will be ignored and the experience will become extremely predictable, allowing players to focus entirely on improving their execution.

Potential Community: “Pro” gamers who want to remove every consideration except execution skill, especially random factors.

4. The game has irreducible strategic complexity.

If there are enough choices, mechanics and contexts that nobody can completely predict them all, players must make decisions on incomplete information. This allows for mistakes and adaptations as the game plays out, and the winner is often the player that changes their strategy to fit changing circumstances.

Potential Community:  Gamers that want to invest a lot of time learning a complex game and do not want it to become predictable.

If you can anticipate the eventual balance the community will reach, you can design more intentionally, avoiding features or mechanics that will be removed, and ensure that the experience is tuned properly from the beginning.

Definition: Balanced

Balanced (see also: Fairness, Longevity)

A state in which a game can be played indefinitely by its entire community without developer interventions or player conventions.

There is no such thing as a “balanced game”.

This is not to say that there is no such thing as a perfectly balanced game, but that balance is not a quality of a game at all, but of the experience of playing a game.  And since this experience depends on who is playing, a game can only be considered “balanced” for a specific group of players.

The latest 2d fighting game might be balanced when you and your friends are taking turns mashing buttons, but degenerate into ridiculous 100+ hit combos when mastered by a some over-zealous Japanese teenager.  To be considered truly balanced, a game must go beyond this kind of local balance and be balanced for the entire game community.

Welcome to the Wire

Balance is often temporary; Imbalance usually permanent

In a similar way, it’s clear that any game may be balanced for brief periods of time. Often the most balanced point in a multiplayer game’s life-cycle are the first few nights after launch, before the community has discovered the optimal strategies, glitches and cheap tactics, before the unending train of patches and tweaks.  So any useful definition of balance must also require the game experience to remain stable for a significant time.

Finally, balance requires a certain amount of independence and permanence.  The purpose of balancing a game is to allow players to strategically plan and skillfully execute within an impartial system that they can predict.  This does not happen if the game requires constant changes and tweaks, either by direct developer updates or community-endorsed “honor rules”.

Note:  This definition of balanced does not require that a game be “fun” to be “balanced”.