Is my teacher doing something illegal?

just wondering bcuz he told us to make a war poster from WWII and never gave us a rubric and grades it on w/e he thinks it is. 18/20 4 me bcuz my picture wasn't "creative" when i drew an army star, a camoflauge backround print, and said words like the more mistakes we make,= more fuel 4 "them"... join the army yada yada. and i think creativity can be expressed through words 2! my friend got 20/20 bcuz in pencil she drew this women from a poster online and he knows! i'm like so that is creative, and he is like i said u could do that?!?" ok and also he lets everybody grade each others test and w/e they put is the score he enters, he nvr double checks them. i got back a 9/12 when i added up the scores it was really 11/12 and had him fix it. last of all he gave us a hw worksheet and i found the same1 online by a different teacher.