Its not used for activating or deactivating entitys.
Its used as a check for a condition to exist to allow an action choice.
;Artificial Intelligence Script
;Header
desc = Use Door (Push Open and Push Closed)
;Triggers
:state=0:hudreset,hudx=50,hudy=90,hudimagefine=gamecore\text\pressentertouse.tga,hudname=usedoorprompt,hudhide=1,hudmake=display,state=10
:state=10,plrdistwithin=60:hudshow=usedoorprompt,hudfadeout=usedoorprompt
:state=10,plrdistwithin=60,plrusingaction=1:activate=2
:state=10,activated=2:state=1,setframe=0,sound=$0
:state=1:incframe=0
:state=1,frameatend=0:state=2,coloff
:state=2,plrdistwithin=60,plrusingaction=1:activate=0
:state=2,activated=0:state=3,sound=$1,colon
:state=3:decframe=0
:state=3,frameatstart=0:state=10,setframe=0
;End of Script
As you can see in this door open script, that you apply activate and then check that it exists. After a certian point you assign a different activate value and check for that condition. It gives the ability to do different thing in a script, in this case, Push open a door, then be able to push it closed also.
Hope this helps.
