Trick-or-treat came a week early to the Paramount lot on Thursday night as the studio hosted the preem for the Halloween-themed “Fun Size.”Victoria Justice was joined at the premiere by co-stars Thomas Mann and Thomas McDonell as well as helmer Josh Schwartz. Having spent most of her career on Nickelodeon’s “Victorious,” Justice said the movie gave her the chance to eschew laughs and play a grieving daughter. “I love doing comedy, but some of the best parts about this movie is showing off my dramatic acting skills, too,” Justice said. When it came to that comedy, producer David Kanter explained how the pic was never suppose to be so family friendly. “The pic was originally suppose to be R rated, but after bringing on components like Victoria, it sort of evolved it to something that hit multiple demos,” Kanter said.