CHAPTER 1

THE ADVENTURER


The Adventure is a type of computer game in which the player is placed in an imaginary environment and is required to direct the computer to manipulate this environment, often with the intention of escape, but sometimes with the object of collecting treasure. Normally, in Adventures, these directions are in the form of two words: the first word is a command, and the second is an object which the command may act upon. An example of this could be "GET REVOLVER", where "GET" is the command, "REVOLVER" the object, and the intention is for the computer to pick up a revolver. The converse of picking objects up is dropping them down, the command being "DROP". One Appendix of all the commands and their meanings, and another of all the objects used in the adventures in this book are given at the end.

   Other types of directions are those involving movement, usually in the form of "N", "S", "E", and "W" standing for north, south, east, and west, although "U" for up, and "D" for down are sometimes used. These movements are between locations or places, which are termed as "rooms" to anyone writing Adventures -- this expression will be used throughout this book. This means that even though an area is in the open air, it it still called a room.

   The relevant information is displayed on the computer screen. Firstly, the name of the room is printed out at the top of the screen -- this may take the form of "Prison cell" or "Winding staircase", both rooms being in the model adventure which will be examined in great detail in the next chapter. In the first adventures made on the large mainframe computers there were vivid descriptions for each room. However, this is not truly feasible on the microcomputer as there is not a great deal of memory available for such lengthy descriptions, and after the initial novelty of these wears off, the user gradually becomes uninterested in the technicalities as he or she only really requires the basic room names as markers for their whereabouts in the maze of rooms.

   Secondly, the possible exits from the room in question are printed out. It may be expected that if one goes east and then back west then one will end up back in the same location. However, although this is true of most of the recent adventures, it was not true of many of the earlier adventures. This is a poor technique in programming as a player will be tempted to curse the programmer if he or she finds themselves in a completely different room from the one they would expect themselves to arrive in logically.

   Next, the objects in the room are displayed followed by an inventory of what the player is carrying. Such a constant display of an inventory is yet to be seen in other adventures, although I have employed this feature from quite an early stage in the structures of my adventures. In other adventures it is necessary for one to type out "INVENT" (or something similar) every time that one wishes to see what one is carrying. In my adventures, however, one can see all the time what one is carrying.

   It is useful to have a limit to what one can drop in a room, or carry, at any one time, for the screen can become cluttered if a dozen or so objects have to be printed out in each category of "Objects" and "Inventory". Many adventures have a limit in the inventory only, but not in the number of objects in each room. I define this limit as four for each category in adventures which have around twenty rooms; as the number of rooms approaches fifty or sixty, I raise this limit to six objects.

   Below the printing of the inventory on the screen, an input is asked for. This is where the users may input their two-word commands, or their intended directions. In my adventures only the first three letters of each command and object need to be typed in, although the words may be entered in full if desired. This is quite a common feature as it reduces the amount of labour required in instructing the computer. For example, instead of typing out "EXAMINE CEILING" in full, "EXA CEI" may be entered. Another feature that I have included in the input procedure, is that if the space is accidentally omitted between the two words, then the computer will still accept the command provided that it is able to carry it out, although it will print out "Learn to type".

   The final aspect of the display of the adventure is the printing out of the computer's reactions to the inputted two-word commands. If the computer replies in the affirmative to "GET" or "DROP", then it prints out "O.K.". On the other hand, however, it will print out "I cannot do that" if it is unable to carry out your command. There are various similar reactions, depending on what situation arises.

   Now that the syntax for the display of the adventure has been dealt with, the actual structure of the logic for it must be handled, for problems must be given to the player to solve -- this is what makes the adventure interesting, and a great deal of pleasure can be found in solving a very tricky problem in an adventure. From the model adventure, for example, it is necessary for a magnifiying glass to be carried, before writing, which is too small to read under normal circumstances, can be read.

   The adventurer may gain information by reading any writing that may be found, or by examining objects. For example, in the model adventure, at the "Observation point" , if one examines a window then one will gain the information that a space ship can be seen outside ready to take off.

   A useful technique in adventure logic is to tempt the player into making actions which would not be too beneficial, although he or she may succeed in a problem in spite of yielding to this temptation. From the same adventure, in the "Bell tower" ,if one rings a bell, then the "dead" are woken, object to the noise, and kill you. This leads onto the topic of the death of a character in an adventure. This may occur in two forms, the first being the running out of time -- the amount of time taken is the number of moves made. The use of such a time limit puts pressure on the player to complete the adventure in the most concise way. The other form of death arises when a particular wrong action is made, or the right one is not made.

   Now that the format of the adventure has been made clear, I would like to continue in the next chapter to show how these features are brought together in an adventure and also to show how such an adventure may be written along with the necessary routines which you will be able to apply to adventures which you may try to write yourself in the future.