Worlds Made of Words and Maps
Some games have no pictures. Their world is told in words or drawn by rules. Today you try both — and see how a computer makes a new map every time.
For parents: a one-page guide — dinner questions and the paper game “Computer-Narrator”.
01Remember
Think about each question, then open the answer.
What is a command?
A word or step you use to tell the computer what to do. For example “forward” or “save”.
What does the “if… then…” block do?
It does something only when the condition is true. If it is not true, it does nothing.
What is a variable?
A box with a name that holds a number or a word. You can change what is in it, while the program stays the same.
02Story
A world of words
Remember the cave from the lesson “My Game for Someone”? You play it with words only. It inspired four people at MIT in America: Tim Anderson, Marc Blank, Bruce Daniels and Dave Lebling. In 1977 they decided to make an even better game.
In the cave, commands were two words long. They wanted the computer to understand longer sentences too. So they wrote a parser — a program that reads what you typed and splits it into words. According to Anderson, Marc Blank rewrote the parser again and again — “40 or 50” times.
The game had no name. In its file they called it “Zork” — a nonsense word that people in the lab used for unfinished programs. The name stuck. In 1979 part of the team founded a company, Infocom, and in December 1980 “Zork” came out for home computers too.
A world of rules
Around 1980 two students in California — Michael Toy and Glenn Wichman — also loved word adventures. But they had a problem: once you solve the game, it is the same the next time. So they made a game, “Rogue”, where the dungeon is built again every time you play.
First they tried to do it purely by chance. It did not work: sometimes the stairs to the next level ended up in a room you could not reach! So they added a rule: the level is a grid of 3 rows and 3 columns, the rooms sit in the cells, and then corridors join them. On the screen the map was made of characters, and you were the character “@” — the authors chose it to show “where you’re at”.
“Rogue” was not the first game with a random dungeon, but it gave its name to a whole kind of games — roguelike. Its year is given as “around 1980”: sources are not exact about when the first version was ready.
Two worlds: one is written in words, the other is made by rules. Today you make both.
03Worked example
Every world is a list of places and doors. Here is our little adventure — just three places out of four:
| Place | Exits | Items |
|---|---|---|
| Hall | north → Kitchen · east → Garden | — |
| Kitchen | south → Hall | key |
| Garden | west → Hall | — |
You are in the Hall and type: “go to the north”. Here is what the program does:
Reads (parse)
It splits the sentence into words: “go”, “to”, “the”, “north”. The words “to” and “the” are just filler — the program skips them. “Go” is a verb, “north” is a direction.
Looks it up (look up)
It finds the row for the Hall. Is there an exit “north”? Yes — to the Kitchen.
Updates (update)
Now you are in the Kitchen. If there had been no exit, you would hear “There is no way that direction.”
Says (say)
It writes the description of the new place. The program does not “understand” the adventure. It only compares your words with a list.
A map that makes itself follows four rules:
Put one room in each of the 9 cells.
Start from one room and join every new room to one that is already joined.
Add some more corridors by chance — so there is a choice.
Check: from the start, can you reach every room?
Notice: change the list (the data) and the world is different, while the program stays the same. Both worlds work that way.
04Try it
Everything here is ours — only shapes and words, nothing from other games. The page saves nothing and sends nothing.
1 · Predict
We have 9 rooms in a 3×3 grid. For every pair of neighbouring rooms we flip a coin: with a 50% chance there is a corridor. How often will you be able to reach all 9 rooms from the start?
2 · Run: a small word adventure
Find the book. Type commands (like “go north” or “take key”) or press the buttons. Use the words from the help. There is no hurry.
Also try something the game does not know — for example “fly”. What does it answer?
3 · Change the world — without touching the program
This is the same world as data: the map and the table change while you play. The glowing dot is the place where you are. Press the button and dig a new door.
The new door appeared in the table, while the program for “go” did not change. Try it: take the key and go straight from the Kitchen to the east.
4 · Run and change: a map that makes itself
This map is built again every time you press a button. starttreasurecannot be reached
“By a rule” means: join every new room to one that is already joined, and then add more corridors by chance. Compare the two ways with “100 maps”. Which is more reliable?
05No screen: “Computer-Narrator”
You need: 5 sheets or cards, a pen, an object to be the “key” (for example a button) and a family member who wants to play. You are the computer, and they are the player.
Draw and label 5 “places” on cards (for example Room, Corridor, Yard, Cellar, Attic). On each write one sentence and where the exits are (north, south, east, west). Lay them on the floor like a map. Hide the object in one of the places.
The player cannot see the map. They say commands, and you answer only with allowed answers: the description of the place, “There is no way that direction.” or “I do not understand.” You accept only a few words: go, take, look and the directions.
Do not help or hint. If the player says something outside the list, answer calmly: “I do not understand. Try another word.” This is how a parser works.
Play until they find the object. Then change only the data: move the object and add one door between two cards. Play again with the same rules.
06Make your own
Make a small world of 5 places on paper — for example your school or a park.
- Draw the map and the arrows between places. Write one sentence for each place.
- Invent one item and one locked door. What opens the door?
- Make a coin generator: draw a 3×3 grid of rooms. For every pair of neighbouring rooms flip a coin — heads means a corridor. Can you get from one room to all the others? If not, add corridors until you can.
- Show your world to someone at home and let them play using only the few words you chose.
07What I learned
- A parser reads what you typed, splits it into words and compares them with a list. An unknown word gets “I do not understand”.
- A world is data: places, doors and items. Change the data and the world is different, while the program is the same.
- A map built by a rule keeps every room reachable. A purely random one often leaves rooms out of reach.
The game says “I do not understand” when it does not know a word. And you — how do you tell people that something is not clear to you?
Check yourself
1. What does the parser do in a word game?
2. Why is the rule “join every new room to one that is already joined” better than purely random corridors?
3. The game says “I do not understand”. What does it mean?
It is yours when you can show someone how a game understands a word and how its world is stored as places and doors — and explain why a map made by a rule is more reliable. No points and no rankings — just a skill.
08I have a question
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·Sources
- Title: Worlds Made of Words and Maps (DB-IG-07) · Author: Children's Library, East Accelerator Foundation · Source: original content and our own code for the adventure and the generator, 2026 · Rights: CC BY-SA 4.0.
- The story: re-told in our own words from the public articles “Zork” and “Rogue (video game)” (Wikipedia) and “Zork” on IFWiki, checked on 2 October 2026.
- Primary source for “Rogue”: Michael C. Toy and Kenneth C. R. C. Arnold, “A Guide to the Dungeons of Doom” (University of California, Berkeley).
- Where sources are loose, we say so in the lesson: the year of “Rogue” is “around 1980”.
- “Zork”, “Infocom”, “Rogue” and “Colossal Cave Adventure” are names of games and a company and are used only to name them. We copy none of their texts, maps, pictures, sounds or characters — the adventure and the maps are ours.
- Licence: CC BY-SA 4.0 · Children's Library, East Accelerator Foundation, 2026. You may share and adapt this lesson if you credit the author and keep the same licence. Learning is free forever.