Thanks for the replies guys, I was thinking to have some lottery/competition in some Football game in a short time.
I don't know how it gonna be or works, but I think it at least work a try!
You can check different giveaway/competition thread available on the Game and Round board to get an idea. I believe prediction format is what suitable to use for your giveaway since you want to incorporate it on a football game.
Sportsbet giveaways is the leading casino that use this kind of giveaway format. You can copy their format and modify it base on your preference. Just put a disclaimer for the source of original format if you don’t want to modify any of it. You can use this thread https://bitcointalk.org/index.php?topic=5466451.0 as reference. Looking forward to join your giveaway!
Thank you, this was a very helpful answer. Thanks!