Contents  What is Play  Balance?  Achieving  Balanceability  The Basic Play  Balance Process  Microcalibration  Printable version  Discuss this article

Abstract: There is not a large amount of information on play balance technique widely available. This article is intended to help fill this information vacuum by describing both the nature of play balance and imbalances, as well as a process by which play balance can be achieved. This process relies heavily upon existing systems engineering techniques, as well as accepted game design theory. Liberal amounts of case studies and anecdotes are used to help ground the process in real-world situations.

A lack of play balance often stands in between a great design and a great game. Most designers learn the fundamentals of play balance through trial and error. If they are fortunate enough, they might pick up a tidbit or two passed on by their co-workers. Those that do have expertise in game balance often guard their secrets jealously, or are in job situations where they have little incentive to share the details with others. As a result, while information on play balance does exist, there isn't a terribly large volume of good information available. This article attempts to convey a process with which play balance can be attained.

What is Play Balance?

Sid Meier once said, "A game is a collection of interesting choices". It follows that game elements being out of balance and thereby eliminating choices detracts from the gameplay. Ideally, a game should be a series of choices, ending with victory of defeat or some other end condition. Sometimes, some choices will become unquestionably the only choice, or definitely not a valid choice. If there is only one valid choice at some point, but the game hasn't ended, there is a play balance problem.

Nearly all situations commonly referred to as imbalances can be boiled down to a choice reduction. For instance, in a strategy game, if a particular unit is sufficiently over-effective for its cost, it could make another unit completely useless in most or all circumstances. Not only does this situation leave a player with one real choice (where's the choosing?), but it also leaves the player with numerous irrelevant distractions. These distractions actually detract from the gameplay further by obfuscating it and adding player frustration to the mix.

A good example of an imbalance is present in Monopoly. Late in the game, it is ALWAYS in the players' best interest to sit in jail as long as possible. The dominant late game strategy for players is to get into jail, then not pay their way out, in hopes that others will land on their properties and go bankrupt. Towards the endgame of Monopoly, there really aren't any choices being made - the game is just concluding. No one is choosing whether to buy property or not, seldom is anyone given the opportunity to build new property using tournament rules (because houses are all used up), and trades simply don't happen because property is lumped into monopolies across the board. Once this situation occurs, the game is basically some probability of each player winning that plays out to conclusion. Very little can be done by players (besides luck of dice) to win. This is a sharp contrast with the mid-game and early game of Monopoly, in which fierce politics go on, players attempt to realize strategic trades that subtly benefit themselves and backstab their opponents, and players must carefully decide whether or not to buy the "heavy" yellow/green/dark blue properties.

This illustrates just one type of imbalance. There are many types of imbalances that can exist in games. All imbalances involve choice elimination or a lack of choices in some form.

• Too Expensive/Weak vs Too Cheap/Powerful: Game choices usually have a game-cost associated with them, be it the loss of other choices, game money, or some other commodity. When one choice is either too expensive to be useful, or too cheap to not be the obvious choice, there is a clear imbalance, because one or more choices has been unintentionally nullified. Though his type of imbalance is by far the most common, it can usually be rectified by simple changes in either cost or basic effectiveness of the choice in question.
  
  
• Player-Time Imbalances: Most play balance comparisons are based on the cost of various choices in terms of what the player must give up to choose a particular path. It is very easy to overlook the fact that a player must spend time executing the choice. In a real-time game, the player doesn't have infinite time in the game, so not only is time a resource, but it is a limited resource. In a non-real-time game, time isn't limited, but the player's time is! This imbalances is essentially another version of the too expensive/too cheap imbalance, except the cost associated with the choice is less tangible. A good example of this imbalance is present in Starcraft with the Zerg race. Although the Zerg race units are more or less balanced by cost compared to other races, they are much easier to produce and use in terms of player time. In large part due to this characteristic, the Zerg race was the dominant race in tournaments and competitions for roughly 6 months following Starcraft's release.
  
  
• Imbalances Across Skill Levels: As players improve in skill, the relative effectiveness of game choices may change. If one choice is easy to use well, and another is extremely difficult to use well, then it follows that to an expert player, the relative effectiveness of the two options is very different than the same to a new player. This is a common trap for game developers, since most are closer to the "Expert" side of things, and as a result often lose sight of the new player. On the other end of this equation, is the fact that "evolving" gameplay with regards to skill is generally considered a good thing. It is important to be aware of this balance, and be aware of this phenomena in general.
  
  
• Forced Disadvantage/Advantage: In a player vs player game, some sequences of actions or choices can result in one player being guaranteed an advantage over the other. In addition to satisfying the traditional definition of imbalance (one choice is clearly best), this situation also isn't fair. In a multiplayer game, unfair situations are best avoided, and are a crucial piece of the play balance puzzle.
  
  

All imbalances come back to the original essence of imbalance: choice elimination. When this is kept in mind, it becomes much easier to distinguish between situations that just need to be tweaked into balance, and situations that are fundamentally imbalanced.

Next : Achieving Balanceability