Session 15 — Make Your First Game

Duration: 60 min · Format: live online · Ages: 8–11

Session goal: by the end, students can open Scratch, add a sprite, and use key-press events to make it move and react on the stage.

Before class — prep (5 min)

• Open Scratch in a browser and click Create — you'll screen-share and live-build the whole session. No install needed.
• Have a starter idea ready to build in front of them: a cat that walks left and right with the arrow keys and "meows" when you press the space bar.
• Make sure your sound is on and shared so students can hear the meow.
• Ask students to open Scratch and click Create so they have a blank project ready.

Agenda

0:00 · Hook (5 min)

Ask the class and take a few answers (chat or unmute):

• "What is your favourite game, and what do you do in it — jump, run, shoot, collect?"
• "When you press a key or tap the screen, something happens. Who tells the game to do that?"
• "Could you be the person who decides what happens when a key is pressed?"

Let them guess, then reveal: today you become the boss of the game. You will tell a character exactly what to do when you press a key — and you'll build it yourself in Scratch.

0:05 · Teach — The stage, sprites, and blocks (12 min)

Explain, pointing at each part on your shared Scratch screen:

• The stage is the big white area on the right — it's where the game happens, like a theatre stage.
• A sprite is a character or object that lives on the stage — the cat is a sprite. You can have many sprites.
• Blocks are the coloured puzzle pieces in the middle — you snap them together to give a sprite instructions.
• The sprite list (under the stage) shows every sprite in your project. Click a sprite to give it its own blocks.

Share this diagram so students can find their way around the Scratch screen — the blocks palette, the script area, and the stage:

Demo in Scratch: drag a move 10 steps block (blue, Motion) into the code area and click it. The cat scoots across the stage. Click it again — it keeps going.

⚠ Watch for the mix-up between "stage" and "sprite": students often think the whole screen is the sprite. Point clearly: the cat is the sprite; the white area is the stage it stands on.

Ask: "If I want a second character in my game, what do I add — a new stage or a new sprite?" (Answer: a new sprite.)

0:17 · Teach — Events make things happen (13 min)

Explain: a game has to wait for the player. In Scratch, the yellow Events blocks are the "listeners" — they wait for something to happen, then run the blocks under them.

Demo in Scratch, building it live:

• Drag out when [space] key pressed (yellow, Events).
• Snap play sound [Meow] (pink, Sound) underneath it.
• Press the space bar. The cat meows! Explain: the event listened, then ran the block.

Now show movement with events:

• Add when [right arrow] key pressed and snap change x by 10 under it (Motion).
• Add when [left arrow] key pressed and snap change x by -10 under it.
• Press the arrow keys. The cat slides left and right.

Key point to land: an event block starts the action. Without an event, your blocks just sit there — nothing tells them when to run.

Ask the class: "The change x by 10 block moves the cat right. What number would I use to move it left?" (Answer: a negative number, like -10.)

0:30 · Activity (20 min)

Students build in their own Scratch project. Screen-share your version as a reference but have them build their own.

Build this, step by step:

1. Keep the cat sprite (or click the sprite icon to pick a different one).
2. Add when [right arrow] key pressed → change x by 10.
3. Add when [left arrow] key pressed → change x by -10.
4. Add when [up arrow] key pressed → change y by 10, and when [down arrow] key pressed → change y by -10.
5. Add when [space] key pressed → play sound [Meow] (or any sound).
6. Test all four arrows and the space bar.

Circulate for (in breakout rooms or by asking students to share screens): - Sprites that don't move — usually the event block is not snapped to the motion block (there's a gap). - Students pressing keys but nothing happens — check the block is under the right key in the dropdown. - The cat flying off the edge — that's fine; reassure them, they'll learn to control it next session.

Encourage naming: ask each student to rename their project (top-left box) something like "My First Game."

0:50 · Check for understanding (7 min)

Ask these aloud or drop them in the chat. Answer key (for you):

1. What is the difference between a sprite and the stage? → A sprite is a character or object; the stage is the background area where sprites live and the game happens.
2. What kind of block do you need so a key press makes the cat move? → An event block, like when [right arrow] key pressed — it listens for the key, then runs the blocks under it.
3. To move the cat left, do you use change x by 10 or change x by -10? → change x by -10 — the negative number moves it left.

0:57 · Wrap-up + homework (3 min)

• Ask one student to finish the sentence: "An event block is like a…" (a listener / a helper that waits for the player).
• Homework — Add a Trick: add one new thing your sprite does when a key is pressed — say something with say [Hi!], change colour, or play a different sound. Bring it to Session 16.

Teaching notes

• Correct this misconception: "the blocks run in order, all by themselves." In Scratch, a stack of blocks does nothing until an event (or a click) starts it. Keep pointing at the yellow "hat" blocks.
• Fast finishers (extension): have them build a mini keyboard piano — add several when [key] pressed blocks, each playing a different sound (Scratch has drum and note sounds). Then challenge them to make the sprite change costume on one key so it looks like it's moving its mouth or legs while a sound plays. Ask them to explain out loud which event triggers which action.
• Low-tech fallback: if a student can't run Scratch, pair them with a partner to co-drive one screen, or have them sketch on paper which key does what ("→ = walk right, space = jump") and take turns "being the computer" for a partner.

Practice set

Assign in class or as homework. Answers are for you, after the arrow.

1. Add a sprite and make it move right when you press the right arrow key. → Use when [right arrow] key pressed snapped to change x by 10. Test by pressing the key.
2. Make the same sprite move left, up, and down with the other three arrow keys. → Three more event blocks: left → change x by -10, up → change y by 10, down → change y by -10.
3. Make your sprite play a sound when you press the space bar. → when [space] key pressed → play sound [Meow] (or any sound from the Sound tab).
4. Change the "10" to a bigger number, like 50. What happens? → The sprite jumps a bigger distance each press — it moves faster/further across the stage.
5. Add a second sprite and give it its own key to move (for example, "d" to go right). → Click the sprite, add when [d] key pressed → change x by 10. Each sprite has its own blocks.
6. Make your sprite say "Ouch!" when it reaches the edge — for now, just make it say "Ouch!" on a key press. → when [key] pressed → say [Ouch!] for 1 seconds. (Real edge-detection comes in Session 17.)

Going deeper (optional)

• What do x and y really mean? Show the stage's hidden grid: x is left–right (across), y is up–down. Drag the sprite and watch the x and y numbers change in its info box. Ask: "If x gets bigger, which way does the cat go?" (Right.) This plants the idea of coordinates without any maths lecture — they see it move.
• move 10 steps vs change x by 10. Both can move a sprite. Explain that move goes in the direction the sprite is pointing, while change x always goes sideways. Have them turn the sprite with point in direction and watch how move now goes a different way. This previews steering, which makes games feel alive.

Common mistakes & fixes

• Mistake: blocks are placed near each other but not actually snapped, so nothing runs. → Fix: show the white shadow that appears when blocks are about to connect; drag until you see it, then drop. Wiggle the top block — the whole stack should move together.
• Mistake: the event block has the wrong key in the dropdown (e.g. set to "up" but they press "right"). → Fix: click the little dropdown arrow on the event block and pick the exact key they want.
• Mistake: adding motion blocks to the stage instead of a sprite. → Fix: remind them to click the sprite in the sprite list first; the stage can't move.
• Mistake: expecting the sprite to move when they click the green flag, but only key-press events were added. → Fix: explain the green flag runs when green flag clicked blocks; key-press blocks need the key to be pressed.
• Mistake: using set x to 10 and wondering why the sprite jumps to one spot every time. → Fix: set x puts it at an exact position; use change x to add movement each press.

Vocabulary

Resources

• Scratch — free, in your browser, no install (main tool).
• Scratch Starter Cards — printable idea cards for quick projects.
• Scratch Tutorials — the built-in "Getting Started" walkthrough inside Scratch.
• Scratch Ideas page — starter guides and inspiration for young game-makers.

Next session

Session 16 — Score & Loops: students add a score with a variable, use forever loops to keep the game running, and send messages between sprites with broadcasts.