set mood to 5initialize memory
Public lesson / Scratch & Game Design
Where Does the Score Live?
A space pet insists it was fed, but the program has forgotten. What information must the game remember, when should it change, and when should a new run reset it?
Lesson rhythm
The idea moves toward a demonstration.
Story, problem, or provocation
Name the problem before opening the build.
Theory and concept
Make the hidden rule visible with small tests.
Guided build
Use the idea inside a working project system.
Modification challenge
Change one rule and predict the effect.
Demonstration and cleanup
Explain the result, save safely, and leave a known state.
Learning goals
What students should be able to do and explain.
- Create a meaningfully named variable.
- Set an initial value.
- Update a value from an event.
- Use a value in a condition.
- Separate score, state, and visual display.
Theory kernel
Small examples before the larger build.
change mood by -1update over time
if mood < 2make a decision from memory
set game_state to PLAYINGname the current mode
Guided-build preview
The Suspiciously Emotional Space Pet
Care for an alien pet that may be hungry, tired, delighted, or deeply suspicious of the snack button.
At least two changing needs, Actions that affect those needs, Visible mood or state, Time-based change.
Variables, State, Events, Conditions, Timers.
A working version, one modification, one repaired problem, and an explanation.
Teacher checkpoints
Evidence before adding complexity.
- 1Variable name describes its purpose.
- 2Restart restores the initial value.
- 3One event changes the value once.
- 4A condition reads the value.
- 5Student explains the current state.
Common mistakes
Pause, inspect, and test one cause.
- Variable never resets.
- Several scripts change the score unexpectedly.
- A display is hidden but the value remains.
- Text and number values are compared accidentally.
Modification challenge
Three levels, one concept kept visible.
Higher levels are optional. They deepen the current idea rather than turning a beginner lesson into an unrelated advanced task.
Builder
- Add a second need such as energy.
Inventor
- Make needs affect each other.
Boss Level
- Create named pet states from several variables.
End-of-class demonstration
Explain the work while it is still visible.
- What does the variable remember?
- Where is it initialized?
- Which event changes it?
- Which decision reads it?
- What state is active now?