Special Events - Good
Special events that only take place once in a while can give players a feeling of excitement. Special events are usually themed to certain holidays throughout the year. By offering players unique items and quest they fulfill our curiosity and desire for something different apart from the daily quest grind. Special events are a great way to change the game up and give players a sense of time progression.
Example: Guild Wars 2
In “Guild Wars 2” they have special events like Halloween, Christmas, etc. You can get unique quest rewards During these events. People love them because each year it's something new, and different! One of my personal favorite is the Halloween event because everyone is running around with a burning pumpkin head.
Pokemon Omega Ruby special events are a way to get special Pokemon that are not available to the regular gameplay. This means thousands of people get the opportunity to travel to different locations in real life where they are able to meet other Pokemon enthusiasts and receive a special Pokemon that will become rare because of its unavailability to the public after the event has ended.