Why does my Construct 3 tap event fire twice?

You're using On Touch start AND On Touch end. Both qualify for a quick tap. Replace with the dedicated On Tap event, which fires once per recognized tap.

Difference between On Tap and On Touch object?

On Tap fires for any tap anywhere; On Touch object qualifies by hitting an object. Pair On Tap object filtered by hit-test to scope.

Trigger once condition?

For continuous-trigger events that should fire once per state change, add System → Trigger Once While True condition. Caches the result and re-fires only on rising edge.

Fix: Construct 3 On Tap Fires Twice

Quick answer: Use the Touch → On Tap event, not On Touch start + On Touch end. For continuous booleans, gate with System → Trigger Once While True.

Tap your start button. Game starts twice (or score increments by 2). Touch start and Touch end events both qualify for a quick tap.

The Fix

Replace:
  Event: On Touch start         → Action
  Event: On Touch end           → Action   (remove)

With:
  Event: On Tap on StartButton  → Action

Or for boolean state:
  System: Trigger Once While True
  + Player health < 10
    → Play danger sound

On Tap is a single trigger per recognized tap gesture. Trigger Once While True caches the previous value and only fires on rising edge.

Verifying

Tap once: action runs once. Hold and drag: no firing. Without On Tap: counter ticks twice on quick taps.

“On Tap event. Or trigger once. One fire per intent.”

Related Issues

For Array picking, see Array picking. For Construct 3 family pick, browse the blog index.

Right event. One fire.