Why probability is important

Maths.

It's a dirty word, to a great many people.  It has connotations of being a discipline that only 'geeks' and dweebs should be interested in, and of being an arcane practice that few people can understand well.  It underpins much of our modern life, and has enabled a great revolution in human development, but remains seen as something not quite approachable.  However we may feel about it, each and every time that we unfold our favorite gaming system to play a game and throw dice we're at the mercy of the gods of math.  Specifically, we're dealing with the disciplines of statistics and probability with each chuck of those cubes we love to hate so much.

Now, I'm not here to talk about why each of us should learn basic probability - it simply isn't something that everybody needs to know to make it through their day.  However, its my opinion that every wargame designer should be at least acclimated to the ideas of probability, if not outright able to articulate every detail about the math backing their gaming system.  That's a pretty bold claim, especially coming from a guy with zero game design credentials to his name; why precisely does a designer need to understand these interactions?

Here's the deal.  As I see it, rules sell games to a very limited minority of the gaming populace.  Instead, miniatures sell games.  People buy games because they like the miniatures, or they like the background material - in short, the aesthetics of a game are what makes sales.  But the rules of a game are what give it life, and make you want to use those models over and over again.  They are what drive communities to get together and play a fun game.  And at the very core of that idea - of a fun game - is the unalienable fact that probabilities control the interaction between the players and the ideas your game expresses.

At the most basic level, that's what rules are - they are expressions of the designer's intent, filtered through the players, about what makes for a 'fun' time.  Taking my favorite system as an example again (Heavy Gear Blitz!), the game tries to portray semi-modern combined arms warfare - with the addition of giant robots.  At some point, there's going to be an intersection between an infantryman (or squad of infantry) and a Gear - and how that situation resolves is as much about what the designer writes the rules to be, as the probabilities those rules work out to be.  A designer that's ignorant of probabilities just says something like 'a machinegun should kill infantry most of the time', fudges a number that works with the dice system they are given, and 'playtests' until that 'looks' right.

Unfortunately - playtesting isn't enough.  It's important, most certainly - and I'll talk about it soon enough. But playtesting is subject to many vagaries; different people can remember the same situation slightly different, dice can be badly weighted and few iterations of a playtest can give skewed results.  All of these things are just part and parcel of dealing with people, but they are a poor standard to gauge an interaction over time.  Because if the play testers happen to be lucky, or have a bias towards thinking infantry are too weak, or any number of other factions - the designer gets the idea that the rule isn't solid, and needs toned down.  Repeat ad infinitum and soon enough a rule goes out the door that appears solid on paper; but once it hits the wilds of the gaming tables it's obvious that it's a bad rule.

Enter probability.  By knowing how your system works mathematically, you can match your assumptions to the game mechanics more precisely.  If your expectation is that 'a machinegun kills infantry most of the time' works out to be 60% in your mind, working the probabilities for several scenarios will tell you if that 60% mark is reached or not.  If a playtester comes back saying 'infantry die all the time' you know their report is bogus, or biased - over some aggregate amount of tests, infantry only die 60% of the time, not 100% of the time.  As a designer, this strips away some of the ability for an individual playtester's bias to shine through, and puts that knowledge firmly in your own control.  If every playtester comes back and says 'infantry are dying all the time', maybe your 60% mark is too high.  If only a small group say that, then maybe they have a bias - and you should discount their remarks.  Or maybe there's an interaction you're missing that you need to account for.  But either way you have more context than the guy who flung a dart and hoped for the best.

Therein lies the difference between a designer that understands how his system works mechanically, and one that does not.  The latter designer is a slave to perception, bias and luck; the former still has to contend with bias, but has checks against it, and luck is out the door.  In addition the designer who understands his mechanics can establish 'principles' of the game as a sort of test to see if new units or rules are skewing the design too far from his or her idea.  He can do design independently of playtesting, which allows for more rapid production of material and a more unified finished product.  After all, the success or failure of the line should rely on the people responsible for creating it - not the fans who want their own particular bias to be enshrined as law.

Taking an example from Heavy Gear; in a standard roll of 2D6+0 versus 2D6+0, there's a 40% chance of 'success' for the attacker.  Somewhere down the line, the designers said you need 2 points of success to do damage with a typical weapon.  So the actual chance of doing some sort of total damage is in the 22% range, not 40% - in short, less than 1/4 of the shots in the above situation will result in something a player would consider a 'success' (i.e. damage boxes on a target).  Changing the roll to 2D6+1 vs. 2D6+0 makes it a 60% chance of a 'success'; but still only a 40% chance of a perceivable 'success'.  Does that match the expectation of the designer for the game?  Hard to tell.  But I suspect that somewhere a designer didn't consider exactly how often they wanted a player to have 'success'; instead they just kept massaging numbers until it 'looked right'.  But they are groping in the dark in this case - instead of knowing firmly "I want the success rate to be 60%".

After all, that's what a designer is paid to do - they are there to build a mental scaffolding for the rest of us to participate in.  They are there to chart a course through the conflicting ideas in all the different wargames out there, and hopefully navigate through the shoals correctly.  A large part of that relies on business sense, a good sense of aesthetics and knowledge of their market.  But it also relies on understanding just what their rules are doing - beyond the filter of the biggest fans.  And that requires knowing probability.

Why playing (lots of different) games is important

During Gencon 2011, I ran into an apocryphal story regarding the then the lead designer of the Classic Battletech franchise. According to the legend (which I have never been able to corroborate), the designer had posted to the Classic Battletech forums the comment that he had played his first game of Battletech in seven years, and had remembered how much fun it was. This of course caused an intense cacophony of hate and questions, as fans questioned how a lead designer could be so out of touch with the game. The person who held control over the future of their game, they supposedly cried, was incompetent to actually lead the game into the future. How could he know what course to plot, if he didn't know what the problems were in the first place?

Now, I'm not a Battletech fan (instead being a rabid fan of the Heavy Gear universe published by Dreampod 9). But being a fan of Heavy Gear I've often expressed a similar frustration rooted in different causes - namely, why exactly are people who aren't familiar with the wargame side of the house running the show? To be sure, there is some element of these frustrations that are the natural effect of wanting your favorite thing (be it a sport, religion or game) to align to your own ideas of how it should be organized. Everybody wants to be a generals, and few want to be troopers. That's normal and expected anytime there's a leadership structure in place.

Focusing on the natural leadership dynamic misses an important criticism that's being made in the above statements, though. Wargames are a hobby primarily, and a hobby with a considerable investment. Smaller wargames in particular tend to be risky expenditures of money due to the lack for used material in smaller communities. Most people want to see their games grow and evolve as time goes on, so that it has a continual lifespan. Unlike video games which tend to be picked up and put down within a span of a month or so, wargamers tend to hope for a long 'shelf-life' during which they can enjoy their chosen system or miniatures. To this end refinements and additional 'hooks' need to be continually introduced into the game, in a way that it maintains its identity but still continues to grow.

To this end, a designer has to understand the community's interpretation of a game in order to improve upon it. And the only way to understand is to play; you have to put models to the table and see how your preconditions stand up in the face of evidence to the contrary. Analysis can only get you so far; most wargames (even simple ones) tend to feature enough complexity that it's nearly impossible to keep the entire ruleset in the front of your mind, much less every permutation of rules intersections in your mind. And that's even before you start to interpret the results of those interactions, and see if they match the end design goals for the system you're working on. Most players understand that very clearly, even if at a instinctual level; how can you understand what's not working if you're not playing with it on a regular basis? If you don't play at all, you are going to be nature be blind to the relevance of flaws as exposed by your community - your decision making is entirely intellectual, logical and without any consideration to the psychological and presence implications of any given rule.

Further compounding the outrage is the observation that every group plays a slightly different game, even if the rules are the same. Interpret a rule slightly differently and it may have a very large impact on the way that the game turns out; what we would loosely call the 'metagame' of your local area. Interpreted one particular way a rule may make artillery more powerful than shooting someone with a rifle, while an equally valid alternate interpretation makes the rifle more powerful. The ambiguity of the English language makes these differences possible and potentially disastrous to a community. So not only should game designers be expected to play, but they should be expected to play lots of different groups. Like any good company head they need insights into how the game is played in small enclaves because the insights they can pickup from those games yields a better 'big picture' view of exactly what the game is in the wild - and how much that diverges from your idea of what the game should be.

Now to this point I've talked about why designers should play their own game; but that's only a part of the picture. Remember, gamers want their games to grow, preferably while keeping the games' identity intact. However, growing the game means expanding the boundaries of the game - which is contrary to the march towards perfection that introspection tends to funnel you towards. There is where other, competing games come to the fore; the time-honored tradition of stea... er, borrowing from others is perhaps the most important tool in any game designer's handbook. It's better to leverage the wargaming community as a whole rather than just the limited subset of community that is relevant to your particular game; by doing so not only do you find novel solutions to related situations in your own game, but you also start to keep a pulse on the industry as a whole.

Taking Heavy Gear as an example, it has problems with its Stealth system. It's been through several iterations of design, with varying degrees of success. In each case though the 'solution' shows obvious signs of 'in-the-box' thinking, trying to make the current system work 'better'. The are fewer signs that someone has sat down and said 'look, Infinity does it this way, and Mercs does it this way, and Warmachine does it this way. Do any of those fit the conceptual model we're gunning for?'. You really need to occasionally step back and look at the problem from a high-level rather than trying to ram a solution in using a shoe-horn.

But to do that, you've got to play. You've got to sit down and figure out what Infinity does that you really like, and what it does that you really hate. You need to play Warmachine and figure out that shooting sucks, which is fine for a medieval game, but note that the abstracted bases works just fine in their case. And you need to play Malifaux to learn about their objectives - what works, and what doesn't - and how it can apply to your game.

In short, to be a good game designer, like anything else in life, you've got to be a professional. You've got to practice the craft of designing a game, of learning about all the possible competitors, and welding all the various pieces you have floating about in your mind - and the minds of your community - into one larger whole. It's got to become something you think about, and wonder about and say 'how can this be better?'. You have to contribute to pushing games forward into the future rather than wallowing in past successes.

In short - in order to be a good game designer, you have to be a good gamer. Otherwise you're just a snake-oil salesman.