As it says in the rules (#0.8), Showdown is an exception to the unofficial games rule. This is because it's an essential aspect of the competitive community and many people on our site use it.
As for why the official games rule exists in the first place:
- Most have a lower playerbase than official games, which means you are less likely to get an answer here. There are also so many of them that we cannot hope to cater for them all.
- Documentation for them is worse than official games, so it's harder for us to have the same quality standard as with official games.
- Most fan games have a dedicated community on a forum or discord server or subreddit that will be much more helpful for you than posting about it here.
- Keeping away from fan games helps the community stay focused and more aligned with the main website, which also doesn't include fan games.
