FUNDAMENTALS OF GAME DESIGN, SECOND EDITION

Incorporating the Element of Chance

The role of chance varies enormously from game to game. Some games, such as checkers, make no use of chance at all; in others, such as craps, chance is all-impor­tant. We've seen that skill, not chance, must be the primary factor in determining the player's success. If chance plays a role, how can we ensure that the more skillful player wins? Here are several recommendations.

■ Use chance sparingly. Design the game so that chance affects only a minority of the player actions that lead to victory and the majority of actions depend on skill. This is the simplest solution, but it's not suitable for all types of games.

If chance is to play a larger role in the game, balance its effects as follows:

■ Use chance in frequent challenges with small risks and rewards rather than infrequent challenges with large risks and rewards. Poker provides a good example. Chance plays a large role in each hand, but smart players don't bet large amounts on a single hand; they count on the cumulative effect of good play over many hands. Player skill remains the major factor that determines winners if a game includes enough hands. This approach also appears in war games, in which chance plays a role in the mechanics governing combat between individual units (although not a large role) but plays no direct role in the victory and loss conditions of the mission. The influence of chance on victory and loss occurs frequently but only on a small scale, so good luck tends to cancel out bad luck over time, leaving skill to deter­mine long-term results.

■ Allow the player to choose actions to use the odds to his advantage. If the

player knows the probabilities that significant events will occur, he can make deci­sions that he believes will be to his advantage. Even in a game in which chance plays an enormous role, such as craps, the player may choose to bet on different outcomes that he believes more or less probable. His skill in making decisions in his
favor on the basis of the odds thus plays a role in determining his success. Video games seldom tell players the odds explicitly, but with experience, players come to learn the odds and make good decisions. If a player has no possibility of acquiring knowledge of the odds and gets no opportunity to decide whether to take a risk, chance plays too large a role.

■ Allow the player to decide how much to risk. Allow the player to choose how much he places at risk at frequent intervals. By offering the player this choice, you give him more control over his resources and so tend to reward skill. This again becomes critically important in gambling games, as in the game of poker. If you do not let the player choose how much to risk on any given challenge that involves chance, then the game should not risk too much on his behalf. In a war game, for example, chance typically affects the accuracy of each shot. By sending a unit into combat, the player risks a few health points on each shot and cannot choose how many points he risks. However, he almost always has the option to withdraw the unit from combat (retreat); the number of points at risk is seldom very large; and one shot typically affects only one unit.

Put simply, don't use chance to determine large issues unless the player explicitly chooses to take large risks (and has the option not to).