Starcraft 2 - multi weapons

[Moonwerewolf]

How do i make a unit have multi weapons? i have added 3 ATALaserBattery on it but only 1 shows up

 

[Dr Super Good]

You can not have duplicates of the same weapon. You can however duplicate the weapon 3 times to have 3 copies of it.

Alternativly you can alter the weapon's effect chain so that instead of 3 weapons it just has 3 attacks for every time the weapon goes off. This is the best and most recommended way as it avoids expensive target aqusition tests.