I had observed that the best games have a variety of types of puzzles,
interspersing the major set-piece puzzles with sequences of simple
object-gathering puzzles. This gives a rhythm to the game, motivating the
player and not making it hard all the time.
As a consequence, I got to thinking about how the kinds of puzzles that
occur in games could be classified. The listing here certainly doesn't
cover all puzzles, and many puzzles belong to two or more categories,
but it's a start.
There may be some minor spoilers in the lists of examples below - knowing
what category a puzzle falls into may provide help in solving it.
The solution of the puzzle requires knowing some piece of information
such as the combination for a safe, a password or a telephone number,
and using that information in the appropriate way. The puzzle lies in
the finding of the information
and the realisation of where it is to be used. The application is
Examples: The password problem in Bureaucracy is a superb example;
Hollywood Hijinx has many such.
2. External Knowledge
The player requires particular knowledge not available in the game
to solve a problem; otherwise, the puzzle is as in (1). Usually,
knowledge not in the game is in the game's packaging; extra real-world
information is usually frowned upon as bad practice. (However, it is
sometimes hard to tell when ordinary knowledge of how real-world things
like locks and lifts operate merges into specialised knowledge).
Examples: the maze in Zork II; any game with clues in the packaging
The game makes map-making difficult by calling a number of
locations by the same name, or by randomising the outcome of moving
in a given direction, or by having passages twist and turn so that
leaving a room to the north does not guarantee entering it from the
Example: the mazes in Zork I, the Bedquilt room in Collossal Cave,
the Carousel room in Zork II.
The puzzle presents a device or room that can be controlled in
various ways (for example, by a set of coloured buttons). In order
to solve the puzzle the player must experiment with the controls
and form a theory of what is happening.
Examples: the reservoir in Zork I, the atomic chihuahua in
Hollywood Hijinx, the babel fish dispenser in Hitch-hiker's,
the microwave in Lurking Horror, more or less everything in
The puzzle depends upon a realisation of a global aspect of the
geography of the game, and/or involves some management of time;
typically these puzzles involve timers or clocks or delayed
consequences of actions and a need to make sure that certain objects
are in certain locations at the right time.
Examples: the lift in Hollywood Hijinx, the loud room puzzle in
Zork I. Arguably the pearl in Collossal Cave was an early and
primitive example of this.
6. Physical Modelling
The solution depends upon having an accurate visualisation of the
physical construction of the constituents of the puzzle.
Examples: the see-saw room and the suspended safe (in Hollywood
Hijinx, a game which is full of clever puzzles).
7. Object/Inventory management
A set of puzzles are made hard by restricting the portability of
objects (by placing a small limit on the amount you can hold, by
having tight squeezes which you cannot get through while carrying
anything, theives which steal things), thus requiring the player
to move back and forth a lot, or plan very carefully which objects
Examples: the Plover room and the golden nugget in Collossal Cave,
the gold sarcophagus in Zork I, the whole of Planetfall
8. Object gathering
The puzzle requires an object to be found somewhere else, brought
to the appropriate location and used in the obvious way.
Examples: door/key, monster/sword, darkness/lamp, shopkeeper/money,
river/boat, vehicle/fuel, etc, etc.
9. Arbitrary but clued
The solution requires the player to do something nonsensical or
arbitrary. Luckily, the something has been clued elsewhere.
Examples: magic words.
10. Completely arbitrary
There is no reason or clue to the solution. Such puzzles are generally
included only as a joke.
Examples: the final points in Collossal Cave & the mainframe Zork.
Also games which it may be possible to play without ever getting
access to particular information or objects, such as a game in which
if you wait in a particular room for five turns, a gnome turns up and
offers to sell you an ice-lolly; many players will run out of things
to do in the room before the five turns are up and never discover the
11. Verb selection
The solution is obvious but you need the correct wording. (Usually
such puzzles are mistakes that somehow weren't picked up during
Examples: unlocking the journal in Sorcerer, tilting the plank in
A puzzle is conceptually easy but requires so much typing, note-
taking or map-making that the player gets bored and plays another game
rather than solve the problem.
Examples: mazes in general, the Communication problem in Planetfall.
13. Codes and Riddles
These are problems that must be solve outside the context of the game;
indeed the best examples retain their interest when removed altogether
from the game.
Examples: there are riddles in Zork II, Leather Goddesses of Phobos,
Beyond Zork and elsewhere, coded messages in Hollywood Hijinx,
Leather Goddesses, etc.
Gareth Rees <gd...@phx.cam.ac.uk>