Well, it was less magic and more technology in summoning them. See, we have this thing called Real Solid Vision, which was like... holograms with actual mass. Though, I guess there was some kind of magic involved, since the duel monsters turned out to actually have souls, and it was kind of like Real Solid Vision was giving them a real body...?

[ Honestly, it was all very complicated and it'd probably take up a lot of time explaining everything... including how it was found out that the monsters had souls. Fortunately, Ochako's ramble takes her attention instead, and she laughs a bit when she hears her start to ramble, even when she calls her familiar weird. Plus, her accent was another fun thing to find out about. ]

But yes, actual monsters! There were all kinds of monsters... fairies, dragons, machines, birds, magicians, knights... and because of Real Solid Vision and Action Duels, we could touch, interact, and even ride them! That's kind of where the sports part comes from, since in Action Duels, you're running around the field alongside them.