Destroying a Target

Forget linepick - he just want to get rid of the array index error which noone seems to have addressed.

Note that you don't need to load the bullet sprite 20 times - load it once and use that as a blueprint for the others. The same applies to the sound, load it once as a global and re-use it as and when required.

There are better ways to do this but I didn't want to re-write all your code. The following should sort your array index issue though :

Const type_target=1
Const type_missile=2
Global SOUNDbam = LoadSound("Plasma Gun.wav" )

;Ceating the bullets
Global BULLET = LoadSprite("Shot 1.bmp")
ScaleSprite BULLET,.2,.2
EntityType BULLET,type_missile
EntityRadius BULLET,.02
HideEntity BULLET
Global fullmag=100
Dim bullet( fullmag-1 )
For i = 0 To fullmag-1
	bullet(i)= CopyEntity( BULLET )
	HideEntity bullet(i)
Next

;Creating the targets with an array
Global targets = 20
Dim target_one( targets-1)
For x = 0 To targets-1
	target_one(x)=CreateCube()
	PositionEntity target_one(x),Rand(-600,800)+x*5,60,Rand(-600,800)
	ScaleEntity target_one(x),2,2,2
	EntityType target_one(x),type_target
Next

Collisions type_missile,type_target,2,1

While Not KeyDown(1)

	;Firing bullets
	If MouseHit(1) And reload = 0
		EntityParent bullet(t),gun
		PositionEntity bullet(t),1,500,-10
		RotateEntity bullet(t),-90,0,0
		ShowEntity bullet(t)
		EntityParent bullet(t),0
		t=t+1
		PlaySound SOUNDbam
	EndIf
	
	bulletpath()
	UpdateWorld
	RenderWorld
	Flip

Wend
End

;====================================================================
;====================================================================
;====================================================================

Function bulletpath()

	For q = 0 To fullmag-1
	
		MoveEntity bullet(q),.02,.04,2.5

		If CountCollisions(bullet(q)) > 0

			HideEntity bullet(q)

		Else

			For x = 0 To Targets-1
			
				If EntityDistance(bullet(q),target_one(x)) <= 1
					HideEntity target_one(x)
				EndIf
			
			Next

		EndIf

	Next

End Function