Quick answer: Construct 3 collision missing thin vertical objects (lasers, beams)? Default collision polygon is rectangular; thin shapes need per-pixel.

Laser beam 4 pixels wide; bullet 32 pixels wide. Bullet flies through laser without trigger.

Per-pixel collision

Object > Properties > Collision = Per Pixel. Accurate; expensive; right for thin objects.

Or thicken collision shape

Authoring: 4-pixel laser with 12-pixel collision polygon. Visual stays thin; collision is reliable.

Use raycast

For laser-style instant beams, raycast-based detection. No collision shape needed; the ray is the test.

“Polygon collision has a minimum useful size. Below it, ray or per-pixel is the answer.”

If your game has thin gameplay elements (lasers, wires), plan the collision strategy at design time.

Related reading