[LiquidIce00]

for is a loop
its like while but its special for numbers
that loop is saying

this.i start out at 0
keep going until you are NOT less then npcscount
add 1 to this.i everytime u loop.

and callnpc is a command used to call an if statement true
if you have a whole bunch of npc's in a level and then u do that loop
and
then in a door u put if (open1) { hide; }
the callnpc will call that . it actually calls to every npc on the level cuz of ur loop ...