# Theory: Using Dice as a Design Tool

As players, we sometimes feel like we’re at the mercy of the dice–but as designers, dice work for us. They make what’s going on under a game’s hood explicit, and in doing so enable us to see and work with the often-obscure probabilities underlying the game experience. When used correctly, dice can let us tune a player’s experience to the Goldilocks standard: not too little of anything, not too much, just right.

The great merit of dice is that they give the designer direct access to the player’s chance of succeeding in doing something. A bullet has pretty good odds of harming a soldier, but only a very small chance of disabling a tank. Bullets fired by a modern rifle are more effective at both of those things than a weapon from the Napoleonic era. Using dice, a designer can reach into a game and set those percentages: if history demonstrates that the odds of a bullet stopping a tank are a little less than 3%, requiring players to roll a 12 on two dice will model historical events accurately. If playtesting then demonstrates that bullets need to stop a tank about 15% of the time or else tanks are too strong, requiring a roll of 7 solves the problem.

Managing the odds of success in this fashion does more than just let designers model armor penetration; it provides a way to establish the feel of a game. When something is more likely to happen, players will naturally trend toward strategies that favor doing it. Conversely, actions that are unlikely to work will be a minor part of the overall experience.

Take Warmachine as an example. In Warmachine attacks are made by rolling two dice, adding an attack stat, and trying to equal or exceed the target’s defense. An average Warmachine soldier has a ranged attack skill of 5, and a defense of 12. Thus, on average dice the soldier will hit her target (ranged attack skill 5 + roll of 7 = defense of 12).

Since the average roll is a hit, Warmachine skews toward offensive play. Players are aggressive because they know attacking is likely to be rewarded. The game as a whole ends up feeling very active; attacks are frequent, models are steadly removed from the table, and the game constantly progresses.

Yet, making aggression good on average wasn’t enough for Warmachine’s designers. They added a mechanism by which players could roll three dice to hit instead of two. With three dice even bad rolls are enough to make contact, which lends the game even more energy; attacking isn’t just favored, it’s much better than hanging back.

Of course, too much offense would be a problem–Goldilocks’ lesson is just as applicable here as it was to heat in soup–and the precision with which dice odds can be manipulated enables Warmachine’s designers to add just the right amount of defense back in. The (arguably) best defensive spell in the game adds 2 to a soldier’s defense. That’s enough to warrant going to the trouble of getting that third die, but not so much as to make hitting impossible.

Imagine what Warmachine would be like if the average defense was 13. Now players generally need an 8 to hit–or, looking at it conversely, the average roll misses. With the best defensive spell defenses push up to 15, which can only be hit with any reliability when using the third die. It’s hard to envision that game being a high-energy affair. More likely it would mimic trench warfare, with players waiting to attack until they had a dominant position.

Going beyond the overall feel of the game, dice can also be used for subtler applications. The average defense is 12, but Warmachine’s important leader figures often have defenses in the 15-16 range. As a result, they’re hard to hit. Players are thus incentivized to push their leaders forward and get them involved in the action, which focuses attention on these thematically important pieces. The designers have used dice math to support the narrative of the game.

Subtler still. Not every soldier can add that third die. The ones that can have a much better chance of hitting a defense of 15 or 16. Hence, the soldiers who can “boost” their to-hit rolls are well-suited to knocking out enemy leaders, while those who can’t are usually sent against line troops or relatively immobile heavy targets. By setting where soldiers’ attacks fall on the probability curve, Warmachine’s designers establish their tactical functions.

Subtler still. Rolling a handful of dice is fun. People tend to like picking up and throwing more of them; it’s exciting to see if a big pile of dice will spike to a huge total, or collapse stupendously. By giving the ability to “boost” to thematically important soldiers, the designers link those soldiers with the excitement of the big pile of dice. That encourages people to play them, further reinforcing the game’s narrative and intended theme.

With all of that said, Warmachine’s approach to dice isn’t appropriate to all games. A game about World War I trench warfare probably should favor defense over offense! The take-away point is that dice, correctly implemented with an understanding of the probabilities involved, enable designers to build and modify games with substantial precision.

It’s often hard to judge exactly what effect an element of a game’s design will have. The beauty of dice is that the effect is right there to see: the probability of success is now X. Rather than fearing the randomness of dice, use the macro-level predictability they offer to shape the game they’re in.

## 4 thoughts on “Theory: Using Dice as a Design Tool”

1. I’m not too familiar with Warmachine but reading this post reminded me of the days I used to play Risk up late in college dorms. That game has very simple rules, but is extremely fun especially with a few people.

Even now I feel that there is a huge element of luck in that game (much more than I am normally comfortable with), but in a sense it’s like gambling since there is always a chance you can win, no matter what the situation.

For better or worse I’ve been away from board games (except real classics like Chess) for a long time, but I wonder if somebody could make a WiFi enabled pair of dice to help integrate the computer and paper worlds somehow.

1. There are definitely questions to be asked about the role of luck in design. As you say, part of the fun of Risk is the possibility of the lucky comeback–but going too far down that path makes chance dominant over skill. Does Risk go across that tipping point? If so, is that a problem? Lots of people enjoy Risk, so we know there’s room for games with lots of luck. What does a well-designed luck-driven game look like?

(Maybe the answer is, “it looks like Risk.”)

I feel like there’s a challenge to be accepted here. If only there was a 25th hour in the day . . . .

1. To me the great thing about Risk is that the concept is extremely straightforward (take over the world one country at a time), and the rules are quite simple too (with just a few exceptions or things to learn). You mentioned setup before and I think that is one of the weaknesses of Risk – it takes awhile to setup before you can actually start rolling dice and attacking. And I remember trying Axes and Allies once or twice – the game was much more complex (and even longer) and I felt it wasn’t worth the time since Risk was ‘fun enough’ without the extra stuff.

I am not sure if there is such thing as “too much luck”, since there are games like Casino Slot Machines that are 99% luck and people still play them like crazy. Sure the point there is more “winning money” than pure enjoyment so you could argue they shouldn’t be compared with standard “games”, but I don’t think it’s black or white.

To mention Hearthstone again as an example, I’ve heard people talk about how it has certain random elements, and even one friend of mine said that was a turn off about the game. But I don’t think the average person would choose to play or not play it because it has a certain amount of randomess. I’s a card game after all, and I feel everyone knows there is a certain amount of luck/randomess built into any card game and are usually willing to put up with it.