If they player can operate in only one field, there is a chance that he will become stuck or fall very far behind.
There should be more than one path to the goal, be it a ClearShortTermGoal or a long-term CompellingGoal. (Well, short term goals should be compelling too.) This can be especially relevant in preventing the player from getting stuck in a OnePlayerGame, but can be just as useful if another player is dominating one field of the game.
Called "Provide Parallel Challenges with Mutual Assistance" in Better_By_Design?, April 2002. "Mutual assistance" is essentially PositiveFeedback, but it is especially relevant here. If a player is stuck on one challenge, completing others should make him better able to confront it.
Examples:
- In Deus_Ex?, a ComputerGame, the player usually had several paths to reach a local goal. He could go in guns blazing, sneak around back, and very often hack into the security system (this is very often on the inside, and make the rest of the area easier - PositiveFeedback.)
- Ra? has several categories of tiles, each type of which tends to become better the more one player has.
- Puerto_Rico? has two ways to gain victory points, (shipping and buildings) and several ways to feed either or both of those goals.
- While a cursory glance at Formula_De? would show only one challenge, there is a delicate balance between position and the condition of one's car. A healthy car allows the player to push harder for position, while being ahead can allow a player to relax a little and take it easier on their vehicle.
- The_Settlers_of_Catan? provides victory points for nearly everything you can do.
Therefore, provide more than one way for a player to achieve goals and victories.
CategoryGoodIdea