Learning Goals 3 min
By the end of this lesson you will be able to:
- Assemble a complete day from a written schedule, across several sprites.
- Check a project opens correctly however the previous run ended.
- Save the finished story as an
.sb3file ready to show.
Warm-Up 7 min
Everything this arc needs already exists in your project. Today is about making it hold together from the first frame to the last.
Quick-fire puzzle
Aisyah’s story works beautifully the first time and is wrong every time after. Her cat’s script starts like this. What is missing?
when flag clicked
say [Morning already.] for (3) seconds
next backdrop
Reveal the answer
Nothing sets the starting backdrop, so the second run begins wherever the first one finished — and the cat announces the morning under a night sky.
Four kinds of state stick between runs: the backdrop, and each sprite’s position, size and visibility. A finished project pins all four.
Project brief — what “finished” means 15 min
A project that works once is a demonstration. A project that works every time, for somebody who did not build it, is finished. The gap between the two is smaller than it looks and almost entirely about opening state.
The four things that stick
| What sticks | Symptom if you forget | The fix |
|---|---|---|
| Backdrop | Story opens at the wrong time of day. | switch backdrop to [Blue Sky v] |
| Position | Characters start wherever they finished. | go to x: (0) y: (0) |
| Visibility | Somebody is missing from the opening. | show or hide |
| Size | A character is mysteriously huge. | set size to (100) % |
The stop-sign test
Here is the test that catches everything. Run your project, hit the stop sign in the middle of it, then click the flag again.
Most projects fail this the first time. Running to the end usually leaves things tidy by accident; being interrupted halfway leaves a character invisible, or off to one side, or under the wrong sky. If your opening survives that, it will survive anything.
Give the transitions room
One more thing separates a finished piece from a working one: pacing around the changes. A backdrop switch landing on top of somebody’s last word feels like a mistake even when it is not. A beat either side costs one wait block and makes the whole thing feel deliberate.
Why this is a project lesson
You are not learning a block today. You are learning what it takes to hand something to another person and have it work — which is a different skill, and the one that makes the difference between a folder of experiments and a piece of work.
Guided Build — finishing the day 15 min
We take the day you already have and make it survive being handed to somebody else.
Step 1 — Get the schedule out
Put your chart from Lesson 32 in front of you. If you do not have one, write it now — you cannot finish a project whose timings you are guessing at.
Step 2 — Give the cat a complete opening
The cat owns the backdrop, so its script sets the time of day as well as its own state.
when flag clicked
switch backdrop to [Blue Sky v]
show
go to x: (-90) y: (-40)
say [Morning already.] for (3) seconds
wait (1) seconds
next backdrop
Step 3 — Give the hen a complete opening too
Every sprite needs its own, because no sprite can set another’s state.
when flag clicked
show
set size to (100) %
go to x: (60) y: (-30)
wait (8) seconds
say [Time to roost!] for (2) seconds
hide
Step 4 — Run the stop-sign test
Play it, hit the stop sign about six seconds in, then click the flag. Everything should be back at dawn with both characters present.
If the hen is missing, its script has no show. If the sky is wrong, nothing set the backdrop. This single test finds almost every remaining bug.
Step 5 — Add the second time change
Extend the cat’s script so the day reaches night, keeping to the schedule.
when flag clicked
switch backdrop to [Blue Sky v]
show
go to x: (-90) y: (-40)
say [Morning already.] for (3) seconds
next backdrop
wait (4) seconds
next backdrop
Step 6 — Fix the hen’s timing to match
The night now falls at seven seconds, not eight. Change the hen’s wait to 7 so it roosts as the sky darkens rather than a second late.
Update your written schedule at the same time. A chart that disagrees with the project is worse than no chart at all.
Step 7 — Watch it as a stranger
Play it through without touching anything and ask yourself what somebody who did not build it would understand. Anything you find yourself explaining is something to fix.
Step 8 — Add a beat where it feels rushed
If a line lands on top of a backdrop change, put a one-second wait between them. This is the cheapest polish available.
What changed: your project stopped being something you can demonstrate and became something you can hand over.
The full assembled scripts (your reference)
when flag clicked
switch backdrop to [Blue Sky v]
show
go to x: (-90) y: (-40)
say [Morning already.] for (3) seconds
next backdrop
wait (4) seconds
next backdrop
when flag clicked
show
go to x: (60) y: (-30)
wait (7) seconds
say [Time to roost!] for (2) seconds
hide
Try It Yourself — polish the day 12 min
Goal: Add a beat either side of each backdrop change and compare how the story feels.
when flag clicked
switch backdrop to [Blue Sky v]
say [Morning already.] for (3) seconds
wait (1) seconds
next backdrop
wait (1) seconds
say [Busy day ahead.] for (3) seconds
Think: take both waits out and run it again. The change lands on top of the dialogue and the whole thing feels hurried, though nothing else altered.
Goal: Give the cat something to do as well as say — a walk that happens during one of the times of day.
when flag clicked
go to x: (-170) y: (-40)
repeat (5)
next costume
move (50) steps
wait (0.2) seconds
end
Think: this walk takes about a second, so it has to fit inside a gap your schedule already has. Adding it without checking the chart will push everything else out.
Mini-mission: hand it over. Give your project to a classmate with no explanation at all, and watch them play it.
It works if: they start it without being told how, follow the story without asking questions, and you never once have to explain what is meant to be happening. Fix whatever forced you to speak.
Think: the things you have to explain are almost always timing that is too fast or a change nobody was given time to notice.
Mini-Challenge — the interruption test 5 min
“Stop it anywhere”
Prove your project opens correctly no matter where it was interrupted. Not once — five times, at five different moments.
It works if:
- You stop the project at five different moments and restart each time.
- All five openings are identical — same backdrop, same characters, same places.
- Nobody is missing, oversized, or in the wrong spot.
- You can name which reset block saves you in each case.
Reveal what usually fails (teacher)
Almost always the sprite that hides. Stopping the project after a hide leaves it invisible, and unless its own flag script begins with show, it never comes back.
The second most common is position, when a sprite walks during the story and nothing sends it home. Both are invisible if you only ever test by letting the project run to the end.
Recap 2 min
Finishing a project is mostly about opening state. Four things stick between runs — the backdrop, and each sprite’s position, visibility and size — and a finished project pins all four before anything else happens. The stop-sign test is what proves it, because running to the end tidies up by accident and hides the problem. Beyond that, polish is small waits around transitions and watching it once as though you had never seen it.
- Opening state
- Everything a script sets before the story starts, so every run begins the same way.
- Interruption test
- Stopping a project partway and restarting, to check the opening still works.
- Transition beat
- A short wait either side of a scene change, so it does not feel rushed.
- Finished
- Works for somebody who did not build it, without explanation.
Homework 1 min
The handover. Get somebody at home to play your project without help.
- Open your saved file and hand over the mouse. Say nothing.
- Write down every moment they hesitated or asked a question.
- Fix at least two of those things.
- Screenshot your Script Area after the fixes.
when flag clicked
switch backdrop to [Blue Sky v]
show
go to x: (-90) y: (-40)
set size to (100) %
Bring back next class:
- Your list of hesitations and your screenshot.
- Your answer to: “What did you have to explain out loud, and how did you change the project so you would not need to?”
Heads up for next class: SCR-L01-35 starts a new arc. Your projects have looked good for a while — now they start to sound like something.