Decoration. If you add (ugly) more tracks, you can really play roulette (see more detailed description).
Source
You can build tracks underground, which accelerate a Minecart to a random speed. The Minecart then serves as a roulette ball and you bet on the corner of which you hope that the Minecart stops there. But I find it ugly, so I didn't do that. How this works can be seen in this video from sethbling:
The idea is from reddit, right?
I got it from the video and he got it from Reddit, as you can infer from the information given above.
Uh-huh.
Supaaa! 😉
Hehe I gamble a round
Very cool 🙂 used it on my server 🙂 .
Very cool 🙂 used it on my server 🙂 .