Lab 6: Text Adventure


Description of the Adventure Game

One of the first games I ever played was a text adventure called Colossal Cave Adventure. You can play the game on-line here (1), here (2) or here (3) to get an idea what text adventure games are like. Seriously, give it a try. Otherwise it will be hard to understand what we are trying to do here.

Arguably the most famous of this genre of game is the Zork series.

The first “large” program I created myself was a text adventure. It is easy to start an adventure like this. It is also a great way to practice using lists. Our game for this lab will involve a list of rooms that can be navigated by going north, east, south, or west. Each room will be a list with the room description, and then what rooms are in each of the directions. See the section below for a sample run:

Sample Run

You are in a dusty castle room.
Passages lead to the north and south.
What direction? n

You are in the armory.
There is a room off to the south.
What direction? s

You are in a dusty castle room.
Passages lead to the north and south.
What direction? s

You are in a torch-lit hallway.
There are rooms to the east and west.
What direction? e

You are in a bedroom. A window overlooks the castle courtyard.
A hallway is to the west.
What direction? w

You are in a torch-lit hallway.
There are rooms to the east and west.
What direction? w

You are in the kitchen. It looks like a roast is being made for supper.
A hallway is to the east.
What direction? w

Can't go that way.
You are in the kitchen. It looks like a roast is being made for supper.
A hallway is to the east.
What direction?

This game assumes you know the material up through Introduction to Lists and Classes, Constructors, and Attributes.

Creating Your Dungeon

Before you start, sketch out the dungeon that you want to create. It might look something like this:


Next, number all of the rooms starting at zero.


Use this sketch to figure out how all the rooms connect. For example, room 0 connects to room 3 to the north, room 1 to the east, and no room to the south and west.

Step-by-step Instructions

As a reminder, at the end of the year I do scan for duplicate homework. I keep all homework assignments from prior semesters, and assignments from non-Simpson students that I find on-line. I run a program that scans for duplicates. Make sure your work is your own.

  1. Define a class called Room as shown in Defining the Class.

  2. Define an __init__ (also known as the constructor) method as shown in Defining the Init Function.

  3. Define class attributes for description, north, east, south, and west as shown in Defining the Init Function. Default description to an empty string, all others to 0.

  4. Update the __init__ method to take in data for all five attributes when the Room is created. So instead of defaulting to zero, now set the elements to the parameters passed in. Refer back to Address Class With Init Parameters for an example of what we are looking for.

  5. Create a main function and call the main function as shown in Creating a Main Function. Make sure your main function is not inside the Room class.

  6. In the main function, create an empty array called room_list. If you’ve forgotten, see Create an Empty List.

  7. Create a variable called room. Set it equal to a new instance of the Room class. For the first parameter, create a string with a description of your first room. The last four elements will be the number of the next room if the user goes north, east, south, or west. Look at your sketch to see what numbers to use. Use None if no room hooks up in that direction. (Do not put None in quotes. Also, remember that Python is case sensitive so none won’t work either. The keyword None is a special value that represents “nothing.” Because sometimes you need a value, other than zero, that represents )

  8. Append this room to the room list. See Adding to a List if you’ve forgotten how to do that.

  9. Repeat the prior two steps for each room you want to create. Just re-use the room variable.

  10. Create a variable called current_room. Set it to zero.

  11. Print the room_list variable. Run the program. You should see a really long list of every room object in your adventure that looks something like this strange line:

    [<__main__.Room object at 0x03800520>, <__main__.Room object at 0x0398F220>,

    If you don’t, make sure you are calling your main function at the end of your program, and that it isn’t indented.

  12. Adjust your print statement to only print the first room (element zero) in the list. Run the program and confirm you get output similar to:

    <__main__.Room object at 0x03800520>
  13. Using current_room and room_list, print the current room the user is in. Since your first room is zero, the output should be the same as before.

  14. Change the print statement so that you only print the description of the room, and not the strange object printing we are getting now. You can do that by appending .description to what you printed in the prior step. When you run it, you should get your room description:

    You are in a room. There is a passage to the north.
  15. Create a variable called done and set it to False. Then put the printing of the room description in a while loop that repeats until done is set to True. We won’t set done to True yet though.

  16. Before printing the description, add a code to print a blank line. This will make it visually separate each turn when playing the game.

  17. After printing the room description, add a line of code that asks the user what they want to do. Use the input statement. Keep in mind that you will be entering letters, therefore you will not want to convert what the user enters to an integer or floating point number. This will be similar to how we got input in Lab 4: Camel. The most frequent mistake I’ve seen students make is to have an input statement and not capture the return value. See Capturing Returned Values if you have this issue.

  18. Add an if statement to see if the user wants to go north. You should accept user input like “n” and “N” and “North” and “NoRtH”. You may need to review Text Comparisons and Multiple Text Possibilities.

  19. If the user wants to go north, create a variable called next_room and get it equal to room_list[current_room].north, which should be the number for what room is to the north.

  20. Add another if statement to see if the next room is equal to None. If it is, print “You can’t go that way.” Otherwise set current_room equal to next_room. Note: This new if statement is part of the if statement to go north. So make sure it is indented inside that if. Also, if you are doing one choice or another, remember to use else.

  21. Test your program. Can you go north to a new room?

  22. Add elif statements to handle east, south, and west. Add an else statement to let the user know the program doesn’t understand what she typed.

  23. It is a great idea to put blank lines between the code that handles each direction. I don’t mean to print a blank line, but actually have blank lines in the code. That way you visually group the code into sections.

  24. It is a great idea to add comments too, to each section.

  25. Test your program. Make sure you have enough of a description that someone running the program will know what direction to go. Don’t say “You are in the kitchen.” Instead say “You are in the kitchen. There is a door to the north.”

  26. Add a quit command that ends the game.

Spend a little time to make this game interesting. Don’t simply create an “East room” and a “West room.” That’s boring.

Also spend a little time to double check spelling and grammar. Without a word processor checking your writing, it is important to be careful. Pay particular note to:

  • In the past I’ve had people capitalize words in this lab that should not be capitalized. Incorrect capitalization of directions are common. See when do you capitalize directions.

  • Do not capitalize room names unless the room name is part of a title. Don’t say “You are in the Living Room,” because the word “living room” isn’t normally capitalized.

Use \n to add carriage returns in your descriptions so they don’t print all on one line. Don’t put spaces around the \n, or the spaces will print.

What I like about this program is how easy it is to expand into a full game. Expanding the game to use all eight cardinal directions (including “NorthWest”), along with “up” and “down” is rather easy. Managing an inventory of objects that can exist in rooms, be picked up, and dropped is just a matter of keeping lists.

Expanding this program into a full game is one of the two options for the final lab in this course.