This article focuses on a common feature of game design, which I will call a "Lock" mechanism. Although Locks may be found in many types of computer games, they are of critical importance to Adventure and Role Playing Games (RPGs.)
In order to craft a superior RPG or Adventure game, the gameís designer must do quite a lot of work. An entire world must be constructed. If the player is allowed to steer his character through this world unhindered, large sections of the game may be missed entirely.
To avoid this problem, the designer implements a Lock. This guarantees that the player will not venture further into the game world until he has more fully explored the areas he has already discovered.
How Does a Lock Work?
Here is a simple example of the Lock mechanism. Suppose that a playerís character has just entered a castle. There is a dungeon beneath the castle, which the player is eager to explore. But as a game designer, you have spent countless hours creating this castle. You have spent many late nights fashioning each NPC, and each has his own, special personality. You certainly donít want the player to bypass all that hard work. How will the player ever appreciate your genius for game design?
In this case, you might use a Lock, something which will prevent the player from venturing into the dungeon. This may be be simple and boring, like a locked door. Or it may be something a bit more interesting, like a disgruntled castle guard who, in a fit of desperation and delerium, has barricaded himself in the dungeonís entrance. Whatever the details, the dungeon is blocked.
In order to progress further into the game, the player must find some way of getting past the Lock. The solution which enables the player to bypass the Lock is called a Key. This may be as simple as finding a key which unlocks the door, or as complicated as solving an intricate puzzle. Whatever the details, the player cannot reach the dungeon until he has explored at least some part of the castle.
Some Common Types of Locks
All Locks have the same basic purpose. They are intended to temporarily block the player from further exploration of the game world. Locks come in many forms. A Lock may be a locked door, a ferocious beast blocking the path, a bad snowstorm which prevents travel, or anything else that a designer can imagine which will do the job.
Some Locks are so common that they deserve special mention. One common type of Lock which is a standard feature of Adventure games and RPGs is the Puzzle. There is a big difference between a puzzle which is used as an element of gameplay (such as in Tetris,) and a Puzzle which is used as part of a Lock mechanism.
Used as a Lock, the point of a Puzzle is to limit access to parts of the game world. Typically, the player encounters some obstacle, such as a path blocked by flooding, a deep chasm which cuts through a path, or something similar. In order to progress further into the game, the player must devise a solution to the Puzzle. Perhaps he must build a boat, or find something to lay across the chasm.
Switch Locks are common in Adventure games. In this case the player may encounter something like an electronic security fence. Or perhaps it is an elevated platform which is too high for the player to reach. Somewhere else, in an area the player has not yet explored, is a Switch will allow him to venture further into the game. The Switch may cut the electricity to the security fence, or it may lower the elevated platform. Of course, the Switch can be a button, computer terminal, or something else. The important point is that the obstacle is overcome by finding a release mechanism in an area some distance from the obstacle.
In RPGs, a player may encounter a Quest. This is also a Lock. In this case the player may not advance the storyline until he has performed some task. He may need to speak with a certain character, retrieve some medicine, slay a monster, rescue someone, find the Sacred Sword of the Goblin Slayers of Old, or whatever the game designer can imagine at the time.