Lesson 14 – Variance

Welcome again, readers, to another week of learning here at Crit the Books. This week, we’ll discuss variance in games, and the different kinds of variance that you will see in games. Variance, often called RNG or chance, is the element of games that adds interest to them beyond strategy. While many players curse games that have heavy variance, I am personally of the opinion that a healthy amount of variance adds a great amount of depth and interest to games. Let’s get into it.

First off, let’s look at exactly what variance is. Variance refers to anything in a game in which the outcome is not wholly predictable. In many games, variance is achieved through 3 main ways – In the case of digital games, a pseudorandom number generator is used to determine results, and in physical games, shuffling a deck or rolling dice are used. While these are the 3 most common, there are certainly other ways that variance can be added to a game. Some games will use coin flips, other social games will use the inherent variance of the human psyche. Regardless, variance does a lot to make games less predictable.

Now that we’ve established what variance is, let’s divide the concept up further to clarify some of our discussions. In games, there are two main types of variance – input variance and output variance. Input variance is variance that changes the options available to a player. The random order of the cards in a digital TCG like Hearthstone, and the cards that you draw, are an example of input variance. You can’t be sure at the beginning of the game which cards will be available for you to play, or what cards you will draw next turn and what options those might allow. You can take guesses and play the odds, but you will never be 100% sure what those options will be unless you have 1 card left in your deck. Since this style of variance changes the options that are available, we call it input variance. It changes what input you, the player, receive.

The other style of variance is output variance. Output variance refers to variances that changes the results of a player’s actions. Looking back at Hearthstone, cards that cast random spells or summon random minions are an example of output variance. You can take the same action as a player two different times – casting Unstable Portal, for example – and get vastly different results. Another example of output variance is the damage roll when you hit with an attack in Dungeons and Dragons. Your attack might deal 1 damage, or it might deal 6. Since you won’t know the precise amount of damage you are dealing, that is another example of output variance.

Many players have a love/hate relationship with variance. How many times have you hit the perfect topdeck and celebrated to yourself or thought, “Yes! Exactly what I needed!”? At the same time, I am certain there have been a number of times that you have made an attack and critically failed it, then looked down and glared at your dice in anger. Many players will say they dislike variance or feel that variance negatively impacts the amount of skill they are able to demonstrate in a game. This stems mostly from the fact that a player can take a strategy that has the highest probability to succeed, but still lose.

However, I am of the opinion that variance is incredibly important to a game’s health overall, and how interesting a game is to play. Whenever variance causes a highly skilled player to lose, it does another very important thing: it makes a less skilled player win. Variance makes games more accessible to newer players, and that is something absolutely critical for the health of a game as a whole. Games that have a low amount of variance – chess or go are wonderful examples – tend to be games that have a very steep learning curve and can quickly become uninteresting when a given play group has known disparities in skill level. If my best friend is a grandmaster at chess, and I am a new player, we are not as likely to enjoy repeated games. My best friend, because he finds the games boring and easy to win; myself because I find my attempts futile and frustrating.

However, games that have a higher amount of variance, such as Hearthstone or Magic: the Gathering, can create situations where even if my opponent is a better player, I drew better cards or had better results of my actions. These games are much more interesting, and while the more skilled player might generally win more often, the less skilled player still feels that they have a chance. This incentivizes both players to play more often and makes it easier for new players to enter the playgroup without feeling like they have a large cliff to climb.

In addition to this, variance makes games interesting. The faster that players can routinely determine the winner of the game from a given board state, the more deterministic the game is and the less interesting it is. For Hearthstone, it is one thing to know that when you are presenting lethal and your opponent has no way to respond to it, you have won. This is as the result of a game played. However, if you could sit down across from your opponent and determine who has won after 2 turns, the game becomes much less interesting and much less worth playing. Variance creates interest by putting players into scenarios where it becomes harder to determine who will win.

When looking at designing a game, I would encourage you to look deeply into what variance exists in your game, and what that variance provides for you. Input variance is a good way to introduce interest into your game without being overwhelming, and also serves as a way to limit complexity for a player on any given turn. When a player has 1000 options, they are more likely to suffer from analysis paralysis than when they have 4. This is also the “safer” type of variance, since players will very rarely feel let down.

Output variance, on the other hand, is the variance of high highs and low lows. This can be a very big negative, since nobody enjoys critically failing their attacks or spending resources to do nothing. However, output variance can also lead to exciting stories of triumphing against overwhelming odds, or of that one time you needed all of the dice to go right to achieve a win, and then they did! Output variance can add a lot of excitement to your game and create strong stories or memories that players will be hard-pressed to forget.

Variance is something that is central to both game play and game design. It’s a subject that I have some strong, and very controversial, opinions on. No matter how you slice it, variance is an integral part of gaming strategy, and learning to love it will get you more familiar with it. Being familiar with variance will open the doorway to being able to make the best use of it in your strategy. Love the variance. It’s here to stay.

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As always, remember that it’s not enough to just hit the books if you want to win. You’ve got to Crit the Books!