Game Balancing - Fundamentals of Game Design - page 352

sink shots because he has fewer balls to target on the table, and his opponent has
more balls left to get in the way. Pool doesn't include positive feedback to help the
leader, so this negative feedback actually tends to keep games close.
Raise the absolute difficulty level of challenges as the player proceeds. This
approach applies primarily to PvE games such as role-playing games. As the player
gains experience points and treasure through successful combat, he obtains more
and more power through positive feedback. In order to continue to offer him
meaningful challenges, increase the strength and numbers of the enemy. Defeating
stronger enemies yields larger rewards, so the cycle continues. Near the end of the
game, he fights enemies hundreds of times more difficult to beat—in absolute terms—
than those that he fought at the beginning, and this gives him a great sense of
accomplishment. But because you have matched the absolute difficulty of the chal-
lenges to the power you provide, the perceived difficulty remains under control.
Allow collusion against the leader. In games with three or more players, you
can write the rules in such a way that the other players can collaborate against the
player in the lead. The collaborating forces may be sufficient to overcome the
effects of positive feedback when the power of a single player might not be.
Diplomacy encourages collusion—forming alliances is the main point of the game.
Define victory in terms unrelated to the feedback cycle. If you define the vic-
tory condition of your game explicitly in terms of player rewards, power, or success
at achievements that make up parts of the positive feedback cycle, then positive
feedback will hasten victory. But you can also define victory in other terms. Taking
a piece in chess confers an advantage to whichever player took it, but the victory
condition in chess requires the player to checkmate his opponent's king, not to
take the most pieces. Although a player may achieve the victory condition more
easily with more pieces, it can also be useful to sacrifice a piece for strategic
reasons.
Use the effects of chance to reduce the size of the player's rewards. Role-
playing games do this to some degree by randomly varying the amount of loot that
enemies yield to the player when they are defeated. By occasionally giving players a
lower reward for their achievements, you slow down positive feedback.
Positive Feedback in Action
The set of graphs in Figure 11.7 illustrates the effects of positive feedback, or its
absence, in a variety of circumstances. Each graph shows the state of a hypothetical
game between two players, A and B, over time. When the curve passes above the
center line and into A's area, A leads; when it goes below the center, B leads. When
the curve reaches the dotted line on one side or the other, the game ends and the
player indicated wins.