Build your own Scratch Pong game

GoalStart with artwork that is already the right size. You will write all of the game code yourself.

1. Download the starter file with the button above, then open the Scratch web editor at scratch.mit.edu/projects/editor.
2. Choose File > Load from your computer and pick scratch-pong-starter.sb3. Loading replaces whatever was open, so save other work first.
3. You should see three sprites: Left Paddle, Right Paddle, and Ball. Click each one. The Code area should be empty.
4. Open the orange Variables category. Left score, Right score, vx, and vy should all be there. Only the two scores show on the stage.
5. Name your project, for example My First Pong Game. Keep this guide and the editor side by side.

GoalThe left player uses W and S. The right player uses the up and down arrows. Paddles only move up and down.

1. Select Left Paddle and build the Left Paddle stack. Each block color tells you which category to open: yellow Events, blue Motion, gold Control, light-blue Sensing, green Operators.
2. Select Right Paddle and build its stack. It starts at x 210 and uses the arrow keys.
3. Everything below go to x goes inside forever. The yellow green-flag block stays on top.
4. Click the green flag, click the stage, then try all four keys. Click the red stop sign when you are done.

when flag clicked
go to x: (-210) y: (0)
forever
if <key (w v) pressed?> then
change y by (8)
end
if <key (s v) pressed?> then
change y by (-8)
end
if <(y position) > (140)> then
set y to (140)
end
if <(y position) < (-140)> then
set y to (-140)
end
end

when green flag clicked
go to x: -210 y: 0
forever
  if <key [w] pressed?> then
    change y by 8
  end
  if <key [s] pressed?> then
    change y by -8
  end
  if ((y position) > 140) then
    set y to 140
  end
  if ((y position) < -140) then
    set y to -140
  end
end

when flag clicked
go to x: (210) y: (0)
forever
if <key (up arrow v) pressed?> then
change y by (8)
end
if <key (down arrow v) pressed?> then
change y by (-8)
end
if <(y position) > (140)> then
set y to (140)
end
if <(y position) < (-140)> then
set y to (-140)
end
end

when green flag clicked
go to x: 210 y: 0
forever
  if <key [up arrow] pressed?> then
    change y by 8
  end
  if <key [down arrow] pressed?> then
    change y by -8
  end
  if ((y position) > 140) then
    set y to 140
  end
  if ((y position) < -140) then
    set y to -140
  end
end

GoalGive the ball two speeds: vx for left and right, vy for up and down. Then start the main game loop.

1. Select Ball and build this stack. The setup blocks run once, before the loop.
2. For the loop, use gold repeat until, not forever. Build its condition now: two green = blocks joined by a green or block, with the orange Left score and Right score reporters inside.
3. Until someone reaches 5, repeat until keeps looping just like forever. You will not need to rebuild this loop later.
4. The set vy block holds a green pick random reporter. The if block after it swaps 0 for 2, so the serve is never perfectly flat.
5. Click the flag. The ball waits, then moves right and up or down. Stop the project: it does not bounce yet.

when flag clicked
say []
set [Left score v] to (0)
set [Right score v] to (0)
go to x: (0) y: (0)
set [vx v] to (4)
set [vy v] to (pick random (-3) to (3))
if <(vy) = (0)> then
set [vy v] to (2)
end
wait (0.7) seconds
repeat until <<(Left score) = (5)> or <(Right score) = (5)>>
change x by (vx)
change y by (vy)
end

when green flag clicked
say []
set [Left score] to 0
set [Right score] to 0
go to x: 0 y: 0
set [vx] to 4
set [vy] to (pick random -3 to 3)
if ((vy) = 0) then
  set [vy] to 2
end
wait 0.7 seconds
repeat until (((Left score) = 5) or ((Right score) = 5))
  change x by (vx)
  change y by (vy)
end

GoalThe top and bottom are walls. The left and right sides stay open so a missed ball can score.

1. Inside Ball's repeat until loop, right after change x and change y, add these two checks.
2. Build each 0 - vy with the green subtract block and the orange vy reporter. Do not type vy into the number box.
3. Do not use if on edge, bounce. It would bounce the ball off the left and right sides too, so nobody could score.
4. Run a few serves. The ball should bounce at the top and bottom but still pass through the paddles for now.

if <(y position) > (173)> then
set y to (173)
set [vy v] to ((0) - (vy))
end
if <(y position) < (-173)> then
set y to (-173)
set [vy v] to ((0) - (vy))
end

if ((y position) > 173) then
  set y to 173
  set [vy] to (0 - (vy))
end
if ((y position) < -173) then
  set y to -173
  set [vy] to (0 - (vy))
end

GoalA hit should send the ball back once, not flip it back and forth while it overlaps the paddle.

1. Add these two checks below the wall checks, still inside Ball's loop.
2. Pick Left Paddle or Right Paddle in the light-blue touching block. Join it to the speed check with a green and block.
3. After a left-paddle hit, set x to -196. After a right-paddle hit, set x to 196. That puts the ball just clear of the paddle.
4. Click the flag and rally. A paddle should only return a ball that is moving toward it.

if <<touching (Left Paddle v)?> and <(vx) < (0)>> then
set x to (-196)
set [vx v] to ((0) - (vx))
end
if <<touching (Right Paddle v)?> and <(vx) > (0)>> then
set x to (196)
set [vx v] to ((0) - (vx))
end

if (<touching [Left Paddle]?> and ((vx) < 0)) then
  set x to -196
  set [vx] to (0 - (vx))
end
if (<touching [Right Paddle]?> and ((vx) > 0)) then
  set x to 196
  set [vx] to (0 - (vx))
end

GoalA miss should add one point, then put the ball back in the middle for the next rally.

1. Add these scoring checks at the bottom of Ball's loop, after both paddle checks.
2. Past x 230 on the right? Left score goes up. Past -230 on the left? Right score goes up. Use change score by 1, not set score to 1.
3. Each branch gets the full reset: center the ball, set vx, pick a new vy, wait 0.7. A right-side miss serves right (vx 4); a left-side miss serves left (vx -4).
4. Move a paddle out of the way on purpose. Watch the score change, the ball reset, and the short pause.

if <(x position) > (230)> then
change [Left score v] by (1)
go to x: (0) y: (0)
set [vx v] to (4)
set [vy v] to (pick random (-3) to (3))
if <(vy) = (0)> then
set [vy v] to (2)
end
wait (0.7) seconds
end
if <(x position) < (-230)> then
change [Right score v] by (1)
go to x: (0) y: (0)
set [vx v] to (-4)
set [vy v] to (pick random (-3) to (3))
if <(vy) = (0)> then
set [vy v] to (2)
end
wait (0.7) seconds
end

if ((x position) > 230) then
  change [Left score] by 1
  go to x: 0 y: 0
  set [vx] to 4
  set [vy] to (pick random -3 to 3)
  if ((vy) = 0) then
    set [vy] to 2
  end
  wait 0.7 seconds
end
if ((x position) < -230) then
  change [Right score] by 1
  go to x: 0 y: 0
  set [vx] to -4
  set [vy] to (pick random -3 to 3)
  if ((vy) = 0) then
    set [vy] to 2
  end
  wait 0.7 seconds
end

GoalYour loop already stops when someone reaches 5. Now announce the winner and end the game.

1. Find the bottom of Ball's repeat until loop. Snap the blocks below underneath it, outside the loop.
2. Build the if/else with a green = block and the orange Left score reporter. Put a purple say block in each branch.
3. Finish with stop all from the gold Control category.
4. Test both winners. After a win, clicking the green flag must clear the message, reset both scores, and move all three sprites back.

if <(Left score) = (5)> then
say [Left player wins! Click the green flag to play again.]
else
say [Right player wins! Click the green flag to play again.]
end
stop [all v]

if ((Left score) = 5) then
  say [Left player wins! Click the green flag to play again.]
else
  say [Right player wins! Click the green flag to play again.]
end
stop [all]

when flag clicked
say []
set [Left score v] to (0)
set [Right score v] to (0)
go to x: (0) y: (0)
set [vx v] to (4)
set [vy v] to (pick random (-3) to (3))
if <(vy) = (0)> then
set [vy v] to (2)
end
wait (0.7) seconds
repeat until <<(Left score) = (5)> or <(Right score) = (5)>>
change x by (vx)
change y by (vy)
if <(y position) > (173)> then
set y to (173)
set [vy v] to ((0) - (vy))
end
if <(y position) < (-173)> then
set y to (-173)
set [vy v] to ((0) - (vy))
end
if <<touching (Left Paddle v)?> and <(vx) < (0)>> then
set x to (-196)
set [vx v] to ((0) - (vx))
end
if <<touching (Right Paddle v)?> and <(vx) > (0)>> then
set x to (196)
set [vx v] to ((0) - (vx))
end
if <(x position) > (230)> then
change [Left score v] by (1)
go to x: (0) y: (0)
set [vx v] to (4)
set [vy v] to (pick random (-3) to (3))
if <(vy) = (0)> then
set [vy v] to (2)
end
wait (0.7) seconds
end
if <(x position) < (-230)> then
change [Right score v] by (1)
go to x: (0) y: (0)
set [vx v] to (-4)
set [vy v] to (pick random (-3) to (3))
if <(vy) = (0)> then
set [vy v] to (2)
end
wait (0.7) seconds
end
end
if <(Left score) = (5)> then
say [Left player wins! Click the green flag to play again.]
else
say [Right player wins! Click the green flag to play again.]
end
stop [all v]

when green flag clicked
say []
set [Left score] to 0
set [Right score] to 0
go to x: 0 y: 0
set [vx] to 4
set [vy] to (pick random -3 to 3)
if ((vy) = 0) then
  set [vy] to 2
end
wait 0.7 seconds
repeat until (((Left score) = 5) or ((Right score) = 5))
  change x by (vx)
  change y by (vy)
  if ((y position) > 173) then
    set y to 173
    set [vy] to (0 - (vy))
  end
  if ((y position) < -173) then
    set y to -173
    set [vy] to (0 - (vy))
  end
  if (<touching [Left Paddle]?> and ((vx) < 0)) then
    set x to -196
    set [vx] to (0 - (vx))
  end
  if (<touching [Right Paddle]?> and ((vx) > 0)) then
    set x to 196
    set [vx] to (0 - (vx))
  end
  if ((x position) > 230) then
    change [Left score] by 1
    go to x: 0 y: 0
    set [vx] to 4
    set [vy] to (pick random -3 to 3)
    if ((vy) = 0) then
      set [vy] to 2
    end
    wait 0.7 seconds
  end
  if ((x position) < -230) then
    change [Right score] by 1
    go to x: 0 y: 0
    set [vx] to -4
    set [vy] to (pick random -3 to 3)
    if ((vy) = 0) then
      set [vy] to 2
    end
    wait 0.7 seconds
  end
end
if ((Left score) = 5) then
  say [Left player wins! Click the green flag to play again.]
else
  say [Right player wins! Click the green flag to play again.]
end
stop [all]

GoalA game is finished when it works every time and you can open it again later.

1. Run the test checklist below, including a win by each player and a fresh restart.
2. Choose File > Save to your computer. Keep the .sb3 somewhere you can find it, and make a spare copy before experimenting.
3. Open a new editor tab, load your saved file, and play again.
4. Pick one challenge from Make it yours. Change one thing at a time and rerun the tests.
5. Sharing is optional. Never put your full name, school, or contact details in a shared project.