Mini Project: The Maze Creator

This lesson has no new blocks in it.

Everything you need you already have. Today is the first time you put all of it together on one build, and find out what eleven lessons adds up to.

What you are making

A maze. A real one, that somebody else can walk into and get lost in:

• an outer wall with a roof, so it is dark inside and you cannot cheat by flying over it,
• partition walls inside it, with gaps that make a path,
• an entrance and an exit on opposite sides,
• mobs loose inside it,
• and a backup copy, so that when somebody knocks a hole in it you can put it back.

Everything comes from somewhere

Nothing below is new. Each part is a lesson you have already done:

The part	Comes from
the outer shell and the roof	Lesson 7 — fill, and hollow
building it where you stand	Lesson 8 — tilde positions
the partition walls, all alike	Lesson 3 — repeat
moving each partition along	Lesson 5 — a variable that grows
the doorways and the entrance	Lesson 7 — filling with air
the mobs inside	Lesson 9 — spawn, in a loop
repairing the damage	Lesson 10 — clone, and a master copy
keeping it readable	Lesson 11 — functions

If any of those feels shaky, this is the lesson where it stops being an exercise and starts being a tool.

⚠️ About the monsters

Your world is set to Peaceful, and monsters will not survive in it.

You have two choices, and the program is identical either way:

• Keep Peaceful and release animals — cows, pigs, chickens. A maze full of livestock is funnier and just as good a test of your code.
• Change Difficulty to Easy in the world settings, and release zombies or skeletons. Do this only if your class is happy with it.

Decide before you start, because it is the one thing you cannot change from inside the program.

How to work today

This is 90 minutes on one build, not six small exercises. So:

1. Plan on paper first. A maze is arithmetic, and arithmetic is much cheaper on paper than in the world.
2. Build the shell before the details. Get the box right, then partition it.
3. Make a backup as soon as anything works — Lesson 10 gave you the command for it.
4. Name things as you go. By Challenge 3 the program is long enough that the names are what stop you getting lost in it.

Warm-up — walk one first

Before writing anything, sketch a maze on squared paper — a box, four or five walls inside it, and a path that winds from one side to the other.

Then count: how many walls, how far apart, where is each gap? Those numbers are your program. You are not designing as you type; you are copying out something you have already worked out.

Build this together. Everyone should finish this part with a maze you can walk into.

Step 1 — The shell

A maze is a box with a lid. You have built that before.

hollow gives you four walls, a floor and a roof, with nothing inside — which is exactly a maze waiting to happen.

Type maze and walk round the outside. It should be a solid, sealed block of stone, 25 by 25.

Step 2 — The way in and the way out

Two air fills, on opposite walls, two blocks high so a player fits.

The entrance is in the wall at ~0; the exit is in the wall at ~24, at the far end. Both are at ~1 to ~2 — the two blocks a player's body occupies.

Walk in. It is a dark empty room, and now it needs walls.

Step 3 — The partitions, with a loop

Here is where Lesson 3 and Lesson 5 come back.

Every partition is the same wall, in a different place. So: one fill in a loop, with a variable that moves it along each lap.

Four walls, at ~4, ~9, ~14 and ~19, each running almost the full depth of the box. Type walls and look down into it from above.

It is not a maze yet — it is a set of sealed corridors. Every wall needs a gap.

Release the mobs.

An empty maze is a puzzle. A maze with something in it is a game.

1. Press C and write a new function called releaseMobs.
2. Using a loop, spawn at least 10 mobs spread through the maze — not all in one spot.
3. To spread them out, move the spawn position each lap with a variable, exactly as the partition walls moved in Basic.
4. Every mob must start inside the maze and not inside a wall. The inside of the shell runs from ~1 to ~23.
5. Add a call to releaseMobs at the end of your maze command.
6. Type maze, then walk in and find them.

Remember the warning about Peaceful in the Introduction. Animals work either way; monsters need the difficulty changed first.

It works if: at least ten mobs are alive inside the maze, spread across more than one section of it, none are stuck inside a wall, and none are outside the outer shell.

Repair the damage.

Somebody will break your maze. Probably you.

1. Make sure your backup command from Basic has been run, and that the master copy is safely out of the way.
2. Now damage the maze on purpose: blow a hole through two or three partition walls with an air fill, or delete a chunk of the roof.
3. Walk in and confirm it is genuinely ruined — you should be able to walk straight through where a wall used to be.
4. Write a command called restore that clones the master copy back over the broken maze and puts it exactly as it was.
5. Type restore, then walk the maze again from the entrance.

Both commands use tilde positions, so where you are standing when you type them is part of the program. Work out how to make that reliable — Lesson 10's extra challenge ran into exactly this.

It works if: after wrecking the maze and typing restore, every wall is back, the path is walkable from entrance to exit again, and the master copy is still intact and ready to use a second time.

A maze to order.

Let the player say how big it should be, and have the program work out the rest.

1. Press C and rewrite your maze command so it takes a number. Rename it size.
2. Guard it, as in Lesson 6: anything under 10 or over 40 gets a helpful message and builds nothing.
3. The shell must be size blocks across, and the partition walls must fit inside it — so how many walls there are has to be worked out from size, not typed in. A 12-block maze cannot hold four walls five apart.
4. Use if / else to make the maze change character with its size. For example: a small maze gets a few mobs and a big one gets many, or small mazes are built in stone and large ones in something darker.
5. Try maze 12, then maze 30, then maze 100, then maze on its own.

Step 3 is the real work. If the walls are five apart, the number of them is roughly size divided by 5 — and the Math drawer has a division block.

It works if: maze 12 and maze 30 both produce complete, walkable mazes of visibly different sizes with walls that fit inside their shells, the two are visibly different in character as well as size, and both maze 100 and a bare maze are refused with a message.