How a 2-Player Controller Works

• Separate Keys: Each player listens for different keys.
• Movement: Change x for left/right, y for jump.
• Battle: Use variables for health and sense collisions for hits.

Step 0: Setup

1. Open Scratch and create a new project
2. Add two sprites: Bear and Opponent (any character)
3. Add a simple stage background

Step 1: Player 1 (Bear) Movement — WASD

when green flag clicked
forever
  if <key [a v] pressed?> then
    change x by (-6)
  end
  if <key [d v] pressed?> then
    change x by (6)
  end
  if <key [w v] pressed?> then
    change y by (8)
    repeat (6)
      change y by (-3)
    end
  end
end

Step 2: Player 2 (Opponent) Movement — Arrow Keys

when green flag clicked
forever
  if <key [left arrow v] pressed?> then
    change x by (-6)
  end
  if <key [right arrow v] pressed?> then
    change x by (6)
  end
  if <key [up arrow v] pressed?> then
    change y by (8)
    repeat (6)
      change y by (-3)
    end
  end
end

Step 3: Health Variables

1. Make two variables: Bear HP and Opponent HP
2. Set both to 100 at the start

when green flag clicked
set [Bear HP v] to (100)
set [Opponent HP v] to (100)

Step 4: Simple Attack + Hit Detection

When Player 1 presses f, check if the bear is touching the opponent. If yes, reduce Opponent HP.

// Bear sprite
when [f v] key pressed
if <touching [Opponent v]?> then
  change [Opponent HP v] by (-10)
end

When Player 2 presses l, check if the opponent is touching the bear. If yes, reduce Bear HP.

// Opponent sprite
when [l v] key pressed
if <touching [Bear v]?> then
  change [Bear HP v] by (-10)
end

Step 5: Win Condition

forever
  if <(Bear HP) <= (0)> then
    say [Opponent Wins!] for (2) seconds
    stop [all v]
  end
  if <(Opponent HP) <= (0)> then
    say [Bear Wins!] for (2) seconds
    stop [all v]
  end
end

Step 6: Visual Health Bars (Top of Screen)

1. Create a new sprite named Bear HP Bar with a green rectangle costume.
2. Place it at the top-left. Duplicate it for Opponent HP Bar (top-right).

Bear HP Bar sprite code:

when green flag clicked
go to x: (-200) y: (160)
set size to (100) %
show
forever
  set size to (Bear HP) %
end

Opponent HP Bar sprite code:

when green flag clicked
go to x: (200) y: (160)
set size to (100) %
show
forever
  set size to (Opponent HP) %
end

Tip: Keep each bar’s original costume the same height and set size by percent so it shrinks as HP drops.

Step 7: Add Punch and Kick

Bear (Player 1): Punch with F, Kick with G

// Bear sprite
when [f v] key pressed // Punch
if <touching [Opponent v]?> then
  change [Opponent HP v] by (-10)
end
wait (0.2) seconds

when [g v] key pressed // Kick
if <touching [Opponent v]?> then
  change [Opponent HP v] by (-15)
end
wait (0.3) seconds

Opponent (Player 2): Punch with K, Kick with L

// Opponent sprite
when [k v] key pressed // Punch
if <touching [Bear v]?> then
  change [Bear HP v] by (-10)
end
wait (0.2) seconds

when [l v] key pressed // Kick
if <touching [Bear v]?> then
  change [Bear HP v] by (-15)
end
wait (0.3) seconds

Optional: Add a short animation or “say [Punch!] for (0.2) secs” when the attack happens.

Extra Challenges

• Add knockback: briefly move the hit sprite backward
• Add animations when attacking or getting hit
• Add a block for “cooldown” so you can’t spam attacks
• Add platforms and gravity for a small arena

Review Questions

1. How did we keep controls separate for each player?
2. How do we check for a “hit” between sprites?
3. Why do we use variables for health?