DC's are currently obsessed with pokemon (aged 4 and 6), as are all their school friends - card trading etc is actively encouraged at the school and supported as a playtime activity. The cards I had less of an issue with, but when I watched this on TV with them it seems little more than glorified dog fighting - in essence on this show they catch wild creatures, store them in a ball, and bring them out to fight whenever they wish (normally cause the 'trainers' ego has been dented), until one of the pokemon gets seriously hurt, then they pop them back into a ball until the next 'battle', the creature has no choice in any of it as far as I can tell.... I'm probably over thinking this but nothing about it seems appropriate for primary aged children to me...