Halloween is hands down the best thing to come from the Pagan beliefs of old. As Halloween is done with, and as the kids all suffer from sugar overdose, let us ponder how Halloween can be used in our empire. First of all, Halloween allows even the most timid to break out of their shell and act the fool. Granted, as shells are broken dangerous ideas are born, but in the eventual sugar overdose, those ideas are soon forgotten in the sugar rush blur. We do not really care about that, we care about increasing our control over the masses. The biggest benefit comes from the costumes. Very quickly you will find those with the most imaginative minds. The most creative, the most likely to come up with fresh ideas. As Overlord you can choose, find this new talent and make use of them, or let them remain anonymous, quietly plotting your down fall.
Hold annual costume contests. Offer large prizes to entice participation. Even offer smaller prizes to all who dress up, sort of like giving them a bone. They will think you are letting them have fun, but you will be secretly taking notes. Use Halloween to your advantage. Exploit your workers. Strengthen your control over them. Bring the kids to the office, give them candy. Now the workers think their families are being taken care of. Major moral boost and in the big picture, cost you very little.