In the campaign i'm currently playing, I'm a celestial sorcerer and i know Silent Image, so while i was in the middle of the battle with my friends i decided to try and create an illusion of a bunch of high soldiers wearing armor and with long lances besides one of my companions to scare the enemies, but the game master told me that i had to make a percentage dice to define the precision and the details of the illusion itself. Also when i tried to move it, i had to make another percentage roll and since I made a bad one he told me that i could not move it. This gave me a strange feeling, because i have never heard of something like that in manuals. Is it normal? The spell already keeps me focused and i can't do anything while i'm casting it, moreover moving it is a standard action, so if there's also the possibility of failing when creating the illusion, i might as well let it go.
