How to make a unit attack ONLY it´s target?

[Kabel]

I want to make my marine really stupid. It shall not attack anything at all unless ordered to do so.

If I hit the A button and attack move to target location the unit will only move there. It shall only attack if I target an enemy unit.

How can this be done?

 

[Dr Super Good]

Although doing this will probably make playing your map annoying as hell...

The idea is to remove the weapon entirly (next to maybe a dummy to show the damage the unit will deal). The actual attack is done by an ability which is set to respond to smart orders (like medivacs do). You can even remove the attack button altogether (I advise this). When the ability is cast at a unit, you initiate a channeling effect which will perodicly (every unit attack period in time) deal damage to the targeted unit. When the unit dies or another order is issued the channeling will be broken so the unit will stop attacking the unit. Animations for the attacks as well as visuals can be set up by actor events.

The key idea is an ability which channels and responds to "smart" orders (right clicks at a target).

 

[Kabel]

I solved this by reduing the scan range to 0 of the weapon. In this way, the unit won´t shoot anything until I click it to attack a specific target.