FUNDAMENTALS OF GAME DESIGN, SECOND EDITION

Game Balancing

To be enjoyable, a game must be balanced well—it must be neither too easy nor too hard, and it must feel fair, both to players competing against each other and to the individual player on his own. In this chapter, you'll learn what qualities a well-bal­anced game has, and how to balance your own. We'll begin by examining dominant strategies and how to avoid them. We'll look at ways to set up and balance both transitive and intransitive relationships among player choices and how to make them simultaneously interesting and well balanced. We'll also look at ways to incorpo­rate chance into games in such a way that the game still rewards the better player.

The bulk of the chapter examines two major issues of balance: fairness and diffi­culty. The meaning of fairness differs between player-versus-player and player - versus-environment games, and we'll address each separately. The question of difficulty applies primarily to player-versus-environment games, and this chapter will expand upon ideas in Chapter 9, "Gameplay," explaining the various factors that affect the player's perception of difficulty and how to manage those factors.

Next we'll look at the role of positive feedback in games: how to use it and how to control it. Finally, we'll briefly investigate the problems of stagnation, trivialities, and how to design your game in order to make the tuning stage of the process easier.

What Is a Balanced Game?

So divinely is the world organized that every one of us, in our place and time, is in balance with everything else.

—Johann Wolfgang von Goethe

As with so many other game design concepts, the conventional notion of balance defies formalization. In the most general sense, a balanced game is fair to the player (or players), is neither too easy nor too hard, and makes the skill of the player the most important factor in determining his success. In practice, several different game features combine to produce these qualities, and game balancing refers to a collection of design and tuning processes that create those qualities in a game under development.

The concept of balance differs considerably depending upon whether we speak of games in which a player plays against one or more opponents (whether human players or artificial opponents implemented by software) or of games in which a player faces challenges posed by the game world, without an opponent. The first
type of game, in which the player faces one or more opponents (even artificial ones), is called a player-versus-player (PvP) game. The second type is a player-versus - environment (PvE) game. As you look at the techniques for balancing a game, note how they differ between PvP and PvE games.

A well-balanced game of either type, PvP or PvE, possesses the following characteristics:

■ The game provides meaningful choices. If the game allows the player to choose from several possible strategies for approaching the game's challenges, no strategy should be so much more effective than the others that there is no point in ever using a different one. If such a dominant strategy exists, it indicates a poorly balanced game. When a game gives a player a choice of strategies, each strategy must have a reasonable chance of producing victory. The later section "Avoiding Dominant Strategies" discusses such strategies.

■ The role of chance is not so great that player skill becomes irrelevant. This does not mean that a player cannot have bad luck, but in the long run—over the course of a long game or over the course of many short games—a better player should be more successful than a poor one.

A well-balanced PvP game also possesses the following qualities:

■ The players perceive the game to be fair. As Chapter 1, "Games and Video Games," explained, the exact meaning of fairness varies among different players. The later "Making PvP Games Fair" section addresses this further.

■ Any player who falls behind early in the game gets a reasonable opportu­nity to catch up again before the game ends. The definitions of early in the game and a reasonable opportunity vary depending on how long the designer expects a game to last. If a player falls behind in the first 10 minutes of a 2-hour game and the rules give him no chance to catch up, most players would perceive that game as unfair, and a game designer would describe that game as poorly balanced. Similarly, a game that the designer intends to last 2 hours but that someone invariably wins in 15 minutes also gives other players no time to catch up or even to test their skill. These imbalances often indicate problems with positive feedback, a game feature that the later section "Understanding Positive Feedback" discusses.

■ The game seldom or never results in a stalemate, particularly among players of unequal ability. A stalemate disappoints players because their efforts produce no victor. If stalemates occur frequently among players of unequal ability, the game violates the principle that player skill should influence the outcome more than any other factor. Chess, though a well-balanced game, can still end in a stalemate, but this seldom happens between players of unequal ability. Other games, such as back­gammon, make stalemates impossible. "Understanding Positive Feedback" addresses this.

In a well-balanced PvE game, these characteristics should be evident:

■ The player perceives the game to be fair. In a PvE game, the player's percep­tion of fairness involves a number of factors and is complicated by the absence of an opponent. The later section "Making PvE Games Fair" addresses these issues.

■ The game's level of difficulty must be consistent. The perceived difficulty of the game's challenges (described later) remains within a reasonable range so as not to surprise the player with abrupt jumps or drops. The perceived difficulty may be low or high but should not change suddenly, especially within a single game level. The later section "Managing Difficulty" discusses this in detail.

To balance your game, you need to use certain design and tuning techniques to be sure the game exhibits these properties. The remainder of the chapter discusses these techniques.