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Asymmetry between players is one of the designer’s best – and most challenging – tools. Not only does it spice up the experience of playing the game, when implemented well it also greatly enhances replayability. Let’s look in detail at the impact it can have, along with why it’s sometimes so hard to incorporate.

What Does Asymmetry Add?

The more new experiences a game can provide players the more replayable it is. One of the best ways to expand that variety is with asymmetric factions. In the original Civilization all of the civs were identical, so outside of one’s imagination there was no reason to ever play anyone but the default. In Civilization 5 this is no longer the case, and the goal of the design team was to have factions that were unique enough to all be worth playing, but not so much so that these differences stole the show from the core mechanics.

Other games fully embrace asymmetry, and almost make experiencing the unique aspects of each side the game. In the old strategy game Master of Magic, each faction was very different – and also fairly imbalanced. But most players shrugged this off because it’s a game about using magic in interesting and “fun” (read: broken) ways. Had Master of Magic been perfectly balanced it likely would have lost much of what made it charming.

Aside from just keeping a game on people’s hard drives longer, asymmetry can also enhance strategic decisions. If all sides play the same way, then the optimal response in an identical situation will always be the same. In Civilization 1, if the player finds him or herself next to a weak, unfriendly rival the right response is basically always to build an invasion force and attack. Once players have figured this out, any true strategy that had once existed vanishes. (One might say that this is mainly an issue of balancing, but there’s no doubt that asymmetry at least helps deflect problems like this!)

While it’s not chunky mechanical design, “feel” is another area where asymmetry can pay large dividends. The three races in Blizzard’s Starcraft series are obviously visually distinct, but their unique mechanics are just as important. The Zerg and Terrans could maintain their excellent art direction, but if they had basically the same units with the same abilities, only with different coats of paint, it would no longer feel like Starcraft. The Zerg are an organic swarm – their units should be more numerous and should have unique abilities like burrowing out of the ground. Their art plus their asymmetric traits is what makes them among the most memorable factions in all of gaming.

The Challenges of Utilizing Asymmetry

One of the toughest problems for me to tackle as a designer of complex strategy titles is finding ways to incorporate asymmetry without breaking what’s already in-place. The fewer moving parts a design has the easier it is to ensure good pacing and balance. This is doubly true when asymmetry is a factor, because it means each side is essentially playing its own slightly-different version of the game.

Last year I had a great discussion with the brilliant David Sirlin about the value and appropriateness of asymmetry. I felt that a sufficiently well-designed game of a certain complexity didn’t need it, and it might in fact be harmful. But David argued that asymmetry makes every game better – it’s just that implementing it properly can be immensely difficult.

I can certainly see David’s case, although I do still believe that there are some games where incorporating asymmetry is unfeasible given the constraints of the real world. If every faction in a Civilization title were as unique as the races in Starcraft, the end result would be an absolutely broken mess. Certainly players would love the extra variety, but a great many would be turned off by the inevitably abysmal pacing and balance. (Heck, some people would argue that’s already the case for the Civ games – well, if you’re one of those people just imagine if it were ten times worse!)

Pacing and balance are certainly important, but my bigger concern with asymmetry in complex strategy games is its potential to lock players into completely obvious and uninteresting paths. “Oh, so the Mongols are the warmonger race? Okay, why should I even bother doing anything else?”

It’s already a tall order to produce a game filled with tough strategic decisions from start to finish. If you have very unique factions then you’re basically multiplying your workload that many more times. Okay, so you have the culture game and the military game balanced with one another and they’re both interesting. You’ve even made it so that switching gears is possible and you always have to consider the best option available. Alright, now make sure that’s true for the warlike Mongols. And the maritime Japanese. And the industrious Germans. Yikes!

Many games aren’t faced with a spiraling complexity of this sort, and for those a great deal of asymmetry probably makes sense. But every project has a limited amount of time and resources. Do you want a more complex game, or a more asymmetric game? Ultimately the designer has to make that call knowing that this decision shapes the direction for every facet of the game.

- Jon