[quote=Boboclown89]
I guess for a plot maybe they create a creature that does not want to be in the arena, and wants to escape by force, and maybe the other creatures that support the tournament have to help and try to stop the creature?
[/quote]

And they'd be trying to cover it up too, since if the public found out that they were being forced to fight each other there'd probably be an outcry for social justice (PETA or whatever, someone would be angry) and that could threaten the whole industry.