Good question! There isn't a specific rule about this, because first and foremost we just want people to be inspired to create new fanworks. If you have a great idea for what happens to be your own prompt - go for it! We'll be happy to give you points for that. Just keep in mind that this community is based around a gift exchange, so use your own judgement in the end - if you want to fill one of your own prompts for Chocobo Races, maybe then make a point to fill a couple prompts from other people too in the coming months :) Thanks for asking!