Download R4CCE, and load the ROM in the Game ID section. It will tell you the Game ID automatically. http://hp.vector.co.jp/authors/VA013928/soft_en.html
Re: YuGiOh! World Championship 2010 - Reverse of Arcadia game id? Enough. We already told you how to find it yourself... Run R4CCE Choose "Add Game" Click the "..." next to the Game ID entry. Select your NDS Rom. R4CCE will tell you the Game ID.