Where can I Play Duel Monsters Online
You can play duel monsters online at Byond.com. Not only does it allow you to play duel monsters, but it also has other games listed and you can create your own games using their software. For more information look here: http://www.byond.com/games/hub/Kajika/DuelMonstersOnline
http://www.yugiohrpgonline.com you can go to this site and duel collect new cards join tournaments and rank up no download needed.