FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
Exploration Challenges
Exploration is often its own reward. Players enjoy moving into new areas and seeing new things, but exploration cannot be free of challenge or it becomes merely sightseeing. Design obstacles that make the players earn their freedom to explore.
The most basic form of exploration challenge simply requires the player to learn her way around an unfamiliar and complicated space. In the old text adventure games, this was particularly difficult because the games lacked visual cues, but even modern 3D environments can be made so tangled that they're hard to navigate. Unfamiliar architecture also challenges the player; navigation is easier when things look the way she expects them to look. Descent required the player to move around a warren of similar corridors inside an asteroid and complicated matters further by setting the environment in zero gravity, so the player perceived no obvious up or down to help her orient herself.
To make spatial awareness challenges easier, give the player a map that always shows his location precisely within the game world. If you want to give the player a map but also make it slightly more difficult, give him a map of the game world that doesn't include his location, so he has to determine his location from landmarks.
Locked door is a generic term for any obstacle that prevents the player from proceeding through the game until he learns the trick for disabling it. A sheet of ice covering a cave entrance that melts if you build a fire constitutes a locked door for game design purposes. Assuming, for discussion only, you want an actual door, you can require that the player find a key elsewhere and bring it back, find and manipulate a hidden control that opens the door, solve a puzzle built into the door, discover a magic word that opens the door, defeat the doorkeeper in a test of skill, or perform some other task—just make sure you offer an interesting and fresh challenge.
Avoid using an unmarked switch far from the door. Doom featured these, and they weren't much fun. Arriving at a locked door and seeing no means of opening it or any clue, the player had to search the entire world pressing unmarked switches at random, returning to see whether one of the switches had opened the door. Worse yet, in a few cases, the switch did open the door, but only for a little while. If the player didn't get back to the door in time, he found it locked again and assumed that switch must not be the right one.
A trap is a device that harms the player's avatar when triggered—possibly killing her or causing damage—and, in any case, discourages her from going that way or using that move again. Similar to a locked door with higher stakes, a trap poses an actual threat. Traps can take a variety of forms:
■ Some fire once and then are harmless.
■ Others fire and require a certain rearming time before they can fire again.
■ Still others respond to particular conditions but not to others, like a metal detector at an airport, and the player must learn what triggers the trap and how to avoid triggering it.
A player may simply withstand some traps that don't do too much damage; he may disarm or circumvent other traps. A trap the player can find only by falling into it is really just the designer's way of slowing the player down; if you make these, don't make many of them because the player can only find them by trial and error and they become frustrating after a while. For players, the real fun comes in outwitting traps: finding and disabling them without getting caught. This gives players a pleasurable feeling of having outfoxed the game.
A maze is an area in which every place looks alike, or mostly alike; to get out, the player must discover how the rooms or passages relate to each other, usually by wandering around. Good designers implement mazes as logic or pattern - recognition puzzles in which the player can deduce the organization of the mazes from clues found in the rooms. Poor mazes offer no clues and make the player find the way out by trial and error. Mazes are now considered rather old-fashioned and difficult to justify in the context of a story, but they can still be fun to solve if you make them truly clever and attractive.
In illogical spaces, areas do not relate to each other in a way that the player might reasonably expect. In text adventures, a player sometimes finds that going north from area A takes him to area B, but going south from area B does not take him back to area A. Illogical spaces require the player to keep a map, because he can't rely on his common sense to learn his way around. Now also considered outdated, and more difficult to implement with today's 3D engines, illogical space challenges still crop up from time to time. If you use them, do so sparingly, and only if you can explain their presence: "Beware! There is a rip in the fabric of space-time!"
Teleporters superseded illogical spaces in the game designer's toolkit. A teleporter is any mechanism that suddenly transports the player from where she is to someplace else, often without warning if the designer created no visual representation for the teleporter device. Several hidden teleporters in an area can make exploration difficult. Teleporters can further complicate matters by not always working the same way, teleporting the player to one place the first time they are used but to some other place the second time, and so on. You can also use one-way teleporters if you want to leave the player with no way to get back.
To make the exploration challenge created by teleporters easier, make the teleporter predictable and reversible, so the player can return at will to where she came from. (A good many games include teleporters not as a challenge but as a visible and optional feature to let the player jump across large distances that she has already explored.)
Many games require the player to find an object hidden somewhere in their simulated space, often in areas that are difficult to get to. Sometimes the objects are hidden in reasonable places that the player can deduce from clues; sometimes they are in obscure ones. The player not only has to learn his way around, he has to keep a sharp lookout for whatever he needs. A number of puzzle games use a variant of the "find the hidden object" challenge in which the player doesn't move through a simulated space, but simply looks at a picture of a room with dozens of objects in it, trying to find the ones required, sometimes against a time limit. This works well in games for casual players who want an uncomplicated point-and-click puzzle, rather like the printed "spot the differences" challenges often found in children's puzzle books.
Easter eggs are a specialized variant of hidden objects. They're items, or sometimes hidden regions or game features, that are fun to discover but not actually needed to win the game—a bonus such as special clothing for the avatar or an extra-powerful weapon. Players love finding Easter eggs. You should hide them in particularly obscure locations.
