Andrew Rollings and Ernest Adams on Game Design

As we said in the introduction, each genre of interactive entertainment displays a common pattern of challenges. In later chapters, we'll look at these genres in detail, examining each to see what can be learned from it:

• Action games normally include physical challenges, puzzles, races, and a variety of conflict challenges, mostly at the personal level. They can also contain simple economic challenges, usually involving collecting objects. They seldom include strategic or conceptual challenges.

• Strategy games tend to include strategic (naturally), tactical, and logistical challenges, in addition to the occasional economic ones. Once in a while, they have a personal conflict challenge thrown in for spice, but this often annoys strategically minded players.

• Most role-playing games involve tactical, logistical, and exploration challenges. They also include economic challenges because the games usually involve collecting loot and trading it in for better weapons. They sometimes include puzzles and conceptual challenges, but rarely physical ones.

• Real-world simulations include sports games and vehicle simulations, including military vehicles. They involve mostly physical and tactical challenges, but not exploration, economic, or conceptual ones.

• Construction and management games such as Roller Coaster Tycoon are primarily about economic and conceptual challenges. Only rarely do they involve conflict or exploration, and they almost never include physical challenges.

• Adventure games are chiefly about exploration and puzzle-solving. They sometimes contain conceptual challenges as well. These may include a physical challenge also, but only rarely.

• Puzzle games tend to be variations on a theme of some kind. Sokoban is about moving blocks around in a constricted space; The Incredible Machine is about building Rube Goldberg contraptions to accomplish particular tasks . The challenges are almost entirely logical, although occasionally there's time pressure or an action element.

Some games cross genres for some reason, combining elements that are not typically found together. The adventure game Heart of China, for example, included a small 3D tank simulator at one point. This is occasionally a design compromise between two people on the team who want the game to go in different directions. It's also sometimes an effort to appeal to a larger audience by including elements that both will like.

Although it can add flavor and interest to a game, crossing genres is a risky move. Rather than appealing to two groups, you might end up appealing to neither . Many players (and game reviewers) prefer particular genres and don't want to be confronted by challenges of a kind that they normally avoid. The wholesale buyers , who are planning to purchase a certain number of games from each genre for their stores, might not know which pigeonhole to put the game into and might shy away from it entirely.

However, you should not allow these genre descriptions to circumscribe your creativity ” especially at the concept stage. If you have a wholly new, never-before-seen type of game in mind, design it as you see it in your vision; don't try to shoehorn it into a genre for the wrong reason. A game needs to be true to itself. But don't mix up genres purely for its own sake. A game should cross genres only if it genuinely needs to as part of the gameplay. A flight simulator with a logic puzzle in the middle of it, just to be different from other flight simulators, will only annoy flight sim fans.